Somatom Sessions Computed Tomography November 2008

SOMATOM Sessions 23

Through a combination of unprecedented speed and innovative dosereduction features, the new SOMATOM Definition Flash offers patients a healthier CT scan.

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SOMATOM Sessions The Difference in Computed Tomography

Issue Number 23/November 2008 RSNA Edition | November 30th – December 05th, 2008

Cover Story SOMATOM Definition Flash Dual Source CT: Leaving Dose Behind Page 6

News Dual Source CT on Scientific Center Stage Page 14

Business RSNA Edition

Global Siemens Headquarters

As Radiation Dose Goes Down, Attractiveness of CT Rises Page 20

Clinical Outcomes

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Coronary CTA with Flash Spiral Scanning in 300 msec Scan Time Page 26

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CT put to the Test Page 56

Science

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Editorial

Imprint

“Lowest radiation dose is important to physicians and patients. It’s important to us.” Sami Atiya, PhD, Chief Executive Officer, Business Unit CT, Siemens Healthcare, Forchheim, Germany

SOMATOM Sessions – IMPRINT © 2008 by Siemens AG, Berlin and Munich All Rights Reserved Publisher: Siemens AG Healthcare Sector Business Unit Computed Tomography Siemensstraße 1, 91301 Forchheim, Germany Chief Editors:

E. Hendrich, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

M. Remy-Jardin, MD, PhD, University Center of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille, France

M. Higashi, MD, Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan

P. Schramm, MD, Department of Neuroradiology, University of Göttingen, Göttingen, Germany

R. Hoffmann, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany T. Jakobs, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany S. Kanzaki, MD, Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan K. Kichikawa, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan S. Kitano, MD, Department of Radiology, Nara Medical University, Nara, Japan

Monika Demuth, PhD (monika.demuth@ siemens.com)

Stefan Wünsch, PhD (stefan.wuensch@ siemens.com)

Responsible for Contents: André Hartung Editorial Board: Andreas Blaha, Andreas Fischer, Thomas Flohr, PhD, Klaudija Ivkovic, Axel Lorz, Jens Scharnagl, Heiko Tuttas, Alexander Zimmermann

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Authors of this Issue: S. Achenbach, MD, Department of Cardiology, University of Erlangen-Nuremberg, Erlangen, Germany

A. Kohli, MD, Department of Radiology, Breach Candy Hospital Trust, Mumbai, India

“The new scanner is a true revolution. We never before dared to scan with such a low dose and such a high speed.”

17.11.2008 7:53:09 Uhr

Editorial

André Hartung, Vice President Marketing and Sales

Dear Reader, For the Siemens Healthcare Sector, being the industry’s innovative leader in medical technology – year after year – has become almost routine. But innovation leadership in pioneering new clinical terrain with unmatched technology alone is not sufficient: From the very beginning, we have maintained a strict focus on patient safety as well. And in computed tomography (CT), patient safety translates primarily into dose reduction. For this reason, we have, from the earliest days, always given dose reduction top priority. The actual danger caused by X-ray radiation in rather low amounts as required for CT scanning is difficult to measure since there exists almost no adequate information or scientific studies on the problem. We have therefore committed ourselves to the ALARA (i. e. As Low As Reasonably Achievable) principle of exposing patients only to the minimum amount of radiation absolutely necessary to achieve the best possible diagnosis. Consequently, in recent years, we have developed many significant products and protocols to conform to the ALARA principle, for example, Adaptive Dose Shield and others that reduce radiation dose to the lowest possible level. Following closely on the development and introduction of Dual Source CT (DSCT) in 2005, we have once again achieved a new milestone in CT dose

reduction with the new SOMATOM® Definition Flash scanner. This scanner delivers greatly improved diagnostic quality with levels of dose lower than ever before possible because its modern and future oriented technology efficiently utilizes the next generation DSCT. With its revolutionary Flash Spiral mode resulting in very high speed, the SOMATOM Definition Flash scanner is not only the lowest dose scanner known today, it is also the fastest, being able to virtually eliminate the need for breath holds and do a whole body scan in four seconds or to scan an entire thorax in less than one second. And it accomplishes these breath-taking performances with the lowest dose known world-wide. Flash speed plus lowest dose are the core of the new scanners’ advantages. Even under unfavorable conditions, the patient’s dose exposure is less than what is required for diagnostic cardiac cath. And triple rule-out examinations are possible with doses below 5 mSv, up to four times lower than any other scanner available on the market. Furthermore the SOMATOM Definition Flash can selectively reduce sensitivearea exposure up to 40% without loss of image quality by turning down the X-ray tube while scanning dose-sensitive body areas such as female breasts. The SOMATOM Definition Flash opens new dimensions for functional 4D imaging

by combining the unique Adaptive 4D Spiral with Flash speed, thereby introducing Adaptive 4D Spiral Plus for longrange dynamic imaging of up to 48 cm, enabling dynamic imaging with half the dose. An additional dose-saving feature is the Selective Photon Shield, filtering out unnecessary photons of the high energy X-ray tubes resulting in a better separation of 80/140 kV images by simultaneously providing dose-neutral, Spiral Dual Energy. In addition to the advanced technology required for lowest dose imaging, adequate training is provided by our highly competent application team so that you and your medical team will be able to take full advantage of both the superior scanning performance and the dosereducing features of the new scanner. With the SOMATOM Definition Flash all patients benefit from the extremely low dose levels, thus making CT a healthier examination than ever before. And your work will be easier and faster, your diagnoses more accurate with completely new clinical applications that only Dual Source CT can provide. Enjoy reading,

André Hartung

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Content

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SOMATOM Definition Flash

Visualization of Brain Vessel Connection

Cover Story

Cover Story The new SOMATOM® Definition Flash Dual Source CT scanner can sweep through the entire thorax in 0.6 seconds and speed through cardiac scans in less than half a heartbeat. But the talk will be about more than speed alone. That’s because the new scanner also promises an impressive reduction in radiation dose for all patients and all types of scans. In a word, the SOMATOM Definition Flash has been designed to be a healthier CT scanner.

6 SOMATOM Definition Flash Dual Source CT: Leaving Dose Behind

News 14 Dual Source CT on Scientific Center Stage 15 First U.S. Payor Reimburses CT Colonography (CTC) for Screening 16 The SOMATOM Definition AS 20-Slice Configuration 16 4D Noise Reduction: New Filter Setting for Dose Decrease and Image Enhancement 17 The Success Story of the SOMATOM Emotion Continues 17 3D on the fly with new syngo WebSpace 2008B 18 Proactive Tube Failure Prediction: Siemens Guardian Program now Includes TubeGuard for the SOMATOM Definition Family 19 Molecular CT – Imaging in Living Colors

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Virtual Histology with DSCT

Siemens Guardian Program Supports Clinical Workflow

Business 20 As Radiation Dose Goes Down, Attractiveness of CT Rises 22 Making a Case for the SOMATOM Emotion 24 syngo WebSpace: Command Central for Fast and Efficient Image Processing

Clinical Results Cardiovascular 26 Coronary CTA with Flash Spiral Scanning in 300 msec Scan Time 28 Low Dose Coronary CTA Reveals High Grade Stenosis 30 Dual Source CT: Pediatric Congenital Heart Disease 32 Identification of Vessel Stenosis of the Lower Leg by Dynamic CT-Angiography Using the SOMATOM Definition AS+ Oncology 34 SOMATOM Definition Dual Energy Scanning: Liver Imaging with Optimum Contrast 36 Lung Parenchyma Analysis Software with Automated Three-Dimensional Quantification of Emphysema

Neurology 38 Acute Left Hemispheric Ischemic Stroke: Comprehensive Stroke Imaging Using Neuro Volume Perfusion CT 40 SOMATOM Definition AS+: Neuro Volume Perfusion CT of Intracerebral Metastatic Disease 42 Dual Source CT: Visualization of Brain Vessel Connection of Siamese Twins 44 A Rare Anomaly of the Middle Cerebral Artery Detected by Three-Dimensional Subtraction CT-Angiography Acute Care 46 Complete Thorax with Flash Spiral 48 Dual Source CT: Carotid Stenosis Diagnosed with Dual Energy Orthopedics 50 Screw Placement and Pelvic Osteoplasty Under CT – Fluoroscopic Guidance

Science 52 CT-Guided Osteosynthesis in Instable Pelvic Fractures 54 Clinical Advantages of Automated CT Tumor Measurement

56 CT put to the Test 60 Virtual Histology with Dual Source CT

Life 64 Proactive Services for and by Radiologists 68 Customer Report: Upgrade from SOMATOM Plus 4 to SOMATOM Definition Delivers a new Picture of Health 70 syngo CT 2008G – New Software Release for SOMATOM Definition 70 CT Research Collaborations in China: a True Win-Win Situation 71 Recording of Hands-on Workshops at ECR 2008 71 New E-Learning for CARE Dose4D 72 Free 90-Day Trial Licenses for Clinical Applications 73 Clinical CT Posters 73 Frequently Asked Questions 74 Clinical Workshops 2009 75 Scientific Photography Prize for Anders Persson 75 Upcoming Events & Congresses 76 Siemens Healthcare – Customer Magazines 77 Imprint

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Cover Story

SOMATOM Definition Flash Dual Source CT: Leaving Dose Behind Through a combination of unprecedented speed and innovative dose-reduction features, the new SOMATOM Definition Flash offers patients a healthier CT scan. By Catherine Carrington

Flash speed. Lowest dose: The new SOMATOM Definition Flash Dual Source CT Scanner is the healthier CT System.

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How can CT scanning become healthier for your patients?

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Cover Story

“Our goal was to build the most patient-friendly CT by significantly reducing dose through faster speed.” Sami Atiya, PhD, Chief Executive Officer, Business Unit CT, Siemens Healthcare

Flash. It’s a word that grabs your attention, immediately evoking speed or brilliance. The new SOMATOM® Definition Flash Dual Source CT scanner hits the mark on both counts. With an acquisition speed and the ability for low dose-scans never before equaled in CT, it outpaces all rivals. It can sweep through the entire thorax in 0.6 seconds and speeds through cardiac scans in less than half a heartbeat. Still, when Siemens Healthcare unveils the SOMATOM Definition Flash at the 2008 annual meeting of the Radiological Society of North America, the talk will be about more than speed alone. That’s because the new scanner also promises an impressive reduction in radiation dose for all patients and all types of scans. In a word, the SOMATOM Definition Flash has been designed to be a healthier CT scanner. “We have a strong focus on putting the patient in the center of all we do,” says Sami Atiya, PhD, chief executive officer of the CT Business Unit of Siemens Healthcare. “Our goal was to build the most patient-friendly CT by significantly reducing dose through faster speed. Lowest radiation dose is important to physicians and patients. It’s important to us.”

How it Works Dual Source technology was introduced by Siemens in 2005 with the launch of the SOMATOM Definition CT scanner. With two X-ray sources and two detectors, the scanner not only enabled an unprecedented improvement in temporal resolution to 83 msec, it also made Dual Energy scanning possible. But the ability of Dual Source CT to push data acquisition speeds to new levels went relatively unrecognized until recently. In one of those “light bulb”

moments, Siemens scientists and engineers realized that with two detectors, it was no longer necessary for the patient table to inch forward during data acquisition. Instead, a Dual Source scanner could achieve gapless z-sampling, even with the wide-open spiral created by a pitch of above 3. That’s because the two detectors create two complementary data spirals that, when put together, include all the information that would be found in a single spiral

“The new scanner is a true revolution. We never before dared to scan with such a low dose and such a high speed.” Willi Kalender, PhD, Director of the Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany

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acquired at a much lower table speed. “The new scanner is a true revolution,” says Willi Kalender, PhD, director of the Institute of Medical Physics at the University of Erlangen-Nuremberg in Erlangen, Germany. “It picks up on the well established concept of Dual Source CT but improves it in several ways. We never before dared to scan with such a low dose and such a high speed.” Not only can the patient table travel at more than 43 cm/sec, the SOMATOM Definition Flash is equipped with two 4 cm detectors that each acquire 128 slices of image data. Gantry rotation time has dropped to 0.28 s, which translates into a temporal resolution of just 75 msec. X-ray tube power has been increased to 2 x 100 kW to accommodate even the most obese patients. Sophisticated technical features further lower radiation dose. All of these features are available merely on the SOMATOM Definition Flash. “The fastest scan is only possible through Dual Source,” Atiya says. “That’s why it’s unique. Unless you have Dual Source technology, you can’t do all these other things.”

The new scanner is of even greater benefit for trauma patients, who are often in too much pain to lie still. With its ability to scan 120 cm in less than three seconds, the SOMATOM Defintion Flash will not only reduce motion and breathing artifacts, but will get the patient out of the CT scanner and into surgery much more quickly. “For the trauma surgeon, the faster you’re done with your scans,

the better,” Nikolaou says. Triple rule-out examinations are also likely to enjoy renewed interest. These all-in-one scans evaluate patients for three common causes of chest pain – pulmonary embolism, aortic dissection, and coronary artery disease. However, their popularity has been hampered by a radiation dose of 15 to 20 mSv, a direct consequence of a lengthy, electro-

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Split-Second Thorax If you want to picture just how fast the SOMATOM Definition Flash is, consider a full thoracic scan that takes about 0.6 seconds. That means, for the first time, that patients will no longer have to hold their breath during scanning. Not only will this be a welcome relief for patients who are sick or injured, it will shorten patient preparation time, an important plus in any busy CT department. “This will save time for the tech,” says Konstantin Nikolaou, MD, an associate professor of radiology and CT section chief at Ludwig Maximilian University of Munich, Großhadern, Germany. “With a very fast scan, you don’t have to train anyone to hold his breath or be concerned about motion artifacts. We will just tell the patient to use shallow breathing, and that should be fine.” Pediatric scanning will also be easier and safer with the SOMATOM Definition Flash.

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Triple rule-out without breath hold in less than one second – at a dose below 5 mSv.

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cardiographic (ECG) gated exams that use a pitch of 0.2 to 0.4. But with the SOMATOM Definition Flash running at a pitch of above 3, a triple rule-out scan will take no more time than a standard thoracic study and expose the patient to no more radiation, approximately 5 mSv. Less contrast material may also be needed. “This protocol facilitates the diagnostic procedure in chest pain patients, as the

scan can be performed very fast and with low dose, while still potentially providing substantial information on the heart and the coronary arteries,” Nikolaou adds. The speed of the SOMATOM Definition Flash promises to boost CT dynamic imaging as well. With its 4 cm detector and a shuttle mode that continuously glides the patient table back and forth, the

SOMATOM Definition Flash is capable of a dynamic scan range of 48 cm, the longest available today. This lengthy 4D spiral opens the possibility of scanning the entire thorax in a time-resolved way. In patients with aortic dissection, the radiologist could watch contrast material flowing in and out of the true and false lumens and observe how various vessels and organs

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Rule-out coronary artery disease for early detection and prevention – Flash Spiral CTA with 0.9 mSv.

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1A

< 1 sec

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1B

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Selective Photon Shield

80 kV Attenuation B < 1 mSv

140 kV Attenuation A

1D 1 Flash speed. Lowest dose: SOMATOM Definition Flash

X-ray off

Split-second thorax: Scanning heart/thorax needs 0.6 s, taking the burden of breath-holding off the patient and allowing functional imaging for body regions up to 48 cm (Fig. 1A). Sub-mSv heart: temporal resolution of 75 msec and scan speed of up to 43 cm/s make heart-scanning without beta-blockers possible or without breath hold a standard with dose levels below 1 mSv (Fig. 1B). Single dose Dual Energy: now dose neutral with the Selective Photon Shield and the widest range of FDA-cleared applications (Fig. 1C).

X-ray on

Organ-sensitive dose protection: The SOMATOM Definition Flash prevents clinically irrelevant dose for spiral examinations and introduces organ-sensitive dose protection (Fig. 1D).

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are supplied. It also offers the option of dynamically scanning the entire abdominal/pelvic region, for example, in a patient with renal cell carcinoma that has metastasized throughout the mesentery. An exciting further development, 4D Noise Reduction, makes it possible to significantly improve image quality with no increase in dose or, alternately, reduce dose up to 50% without compromising image quality. But Nikolaou is also intrigued by the possibility of using the extended dynamic scan range to improve run-off studies of the lower leg. He is already using a hybrid, two-injection technique to achieve a true arterial phase of the lower leg, even in patients with advanced

“For the trauma surgeon, the faster you’re done with your scans, the better.” Konstantin Nikolaou, MD, Associate Professor of Radiology and Section Chief of CT Department, Ludwig Maximilian University, Campus Großhadern, Munich, Germany

peripheral arterial disease. Still, the smaller detector on his existing scanner permits viewing of only about two-thirds of the lower leg. That will change with the SOMATOM Definition Flash. “With 48 cm coverage, you could really have a lower leg CTA with time-resolved imaging,” stresses Nikolaou. “This will definitely change our protocol.”

Sub-mSv Heart Dual Source CT took cardiac imaging to new heights. Now, the SOMATOM Definition Flash goes even further, scanning the heart in about 250 msec at a temporal resolution of 75 msec and with a radiation dose of < 1 mSv. With specs like that, Flash scanning has the potential to stretch cardiac CT applications to include everything from screening to stress myocardial perfusion imaging. Consider the use of CT coronary angiography for preventive screening. It has the potential to unmask a silent killer, but until now, radiation dose has been a significant stumbling block. “If we could detect coronary disease earlier, it might have a tremendous impact on prognosis,” says Jörg Hausleiter, MD, an associate professor of medicine at the German Heart Center in Munich. “But with currently available CT technology, a CT-Angiography of the heart delivers a dose of approximately 13 mSv, which is not acceptable for early detection. Anything less than 2 to 3 mSv would be great.” In addition to the ultra low-dose Flash protocol – which uses a pitch of above 3 – the SOMATOM Definition Flash also offers the Flash Cardio Sequence. This “intelligently triggered” step-and-shoot method is not only suited to higher heart rates, it automatically adapts to variations in cardiac rhythm, ensuring that images are always acquired during diastole. On top of coronary imaging it also allows, for the first time ever, to calculate ejection fraction to the new dualstep pulsing approach. “We’re already doing step-and-shoot with Adaptive Cardio Sequence on our current system, but with the larger

“If we could detect coronary disease earlier, it might have a tremendous impact on prognosis.” Jörg Hausleiter, MD, Cardiologist, Associate Professor of Medicine, German Heart Center, Munich, Germany

detector and the higher temporal resolution of the SOMATOM Definition Flash, we expect to have even better image quality,” Hausleiter says. “It’s probably the most attractive alternative to the pitch 3 Flash mode.” CT myocardial perfusion imaging is another application that is catching the attention of cardiologists. Today, it is possible to do such functional imaging at resting heart rates using Dual Energy. The SOMATOM Definition Flash, thanks to a temporal resolution of 75 msec and a shuttle mode that covers the entire

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myocardium, offers the possibility of doing perfusion imaging at high heart rates, even during exercise or pharmacologic stress. “The role of CT myocardial perfusion imaging is still evolving, but it is intriguing,” Hausleiter says. “This would give us additional information on the severity of the lesion and the hemodynamic impact of that lesion. If we could determine that while the patient is still on the table of the CT scanner, that would be very beneficial.”

3A

3B

Single Dose Dual Energy Dual Energy imaging is made possible by the simultaneous operation of two X-ray sources at different energy levels, which enables differentiation of fat, soft tissue, and contrast material on the basis of their unique energy-dependent attenuation profiles. The SOMATOM Definition introduced Dual Energy in 2005. Since then, the Food and Drug Administration has cleared 10 Dual Energy clinical applications, an achievement only Siemens can claim. Still, Dual Energy imaging is underutilized in everyday clinical practice, in part because of a dose penalty of about 20 percent in some scans e.g. in the case of obese patients. The SOMATOM Definition Flash could change all that. A new Selective Photon Shield pre-filters high kV X-rays, removing low-energy photons. This has two beneficial effects. First, it improves energy separation and, therefore,

3 Fast and reliable removel of calcifications in the entire vasculature with syngo Dual Energy Direct Angio: VRT (Fig. 3A), MIP (Fig. 3B).

material differentiation by 80 percent. Second, it markedly reduces dose. “The availability of a dose-neutral scan is likely to spark renewed interest in Dual Energy,” says Elliot Fishman, MD, a professor of Radiology and director of Diagnostic Imaging and Body CT at Johns Hopkins Medical Institutions,

Baltimore, MD, USA. “If you come up with something new and it has the same or lower dose – and yet provides all sorts of additional information – that becomes very exciting. This new scanner has the potential for raising the bar.” At the same time, new features will make Dual Energy scanning easier to

“The availability of a doseneutral scan is likely to spark renewed interest in Dual Energy.” Elliot Fishman, MD, Director of Diagnostic Imaging and Body CT, Johns Hopkins Medical Institutions, Baltimore, MD, USA

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Cover Story

4A

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4 X-CARE reduces direct exposure of dose sensitive organs, e.g. minus 40% for breast tissue – while maintaining a homogeneous image quality over the entire scan field of view.

use in everyday routine. For example, better image processing, including zerodelay bone removal, will save time. Increased tube power and a wider field of view on the second detector will also expand the possible range of patients and applications. Making Dual Energy images available on syngo WebSpace will enable radiologists to interpret Dual Energy scans from any PC anywhere. “This new scanner has new capabilities that could allow Dual Energy to become a robust study that is part of a routine examination,” Fishman says. “And that this system is better, that it lowers the radiation dose, and speeds up workflow – that will make a tremendous difference.”

Organ-Sensitive Dose Protection The SOMATOM Definition Flash is designed with dose savings in mind. Besides the reduced radiation exposure

that automatically results from the high table speed, the scanner has several other dose-conscious features. The Selective Photon Shield and the ECG-pulsing in the Flash Cardio Sequence are just two. In addition, the new scanner is equipped with Adaptive Dose Shield, which blocks X-rays from the portion of the spiral that will not be used in image reconstruction. This amounts to a half-detector’s width at the beginning and end of each acquisition. In the case of cardiac scans, Adaptive Dose Shield cuts radiation dose by as much as 25 percent. The scanner also features organ-specific dose protection, a technique that enables the radiologist to turn off the X-ray tube during the portion of the gantry rotation that would directly expose radiation sensitive organs, such as the breast, thyroid gland, or eyes. Siemens is already looking to the future, developing iterative reconstruction techniques that promise to further reduce

dose. The idea is to acquire the dataset at a low dose, which results in noisy images. Through repeated reconstruction steps, image artifact and noise are removed, and quality is improved. “I’m impressed by the concept,” Kalender says. “You can scan at a lower dose, and make up for the additional image noise using this new reconstruction method.” “For now, the main limitation to iterative reconstruction is its need for massive computing power,” Atiya says. “But we believe that the iterative reconstruction holds potential and we will be coming up with a first set of applications in the near future.” Medical writer Catherine Carrington holds a master’s degree in journalism from the University of California Berkeley and is based in Vallejo, CA.

Further Information www.siemens.com/somatomdefinition-flash

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More than 400 Dual Source installations worldwide More than 100 peer-reviewed publications Q

Q

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Faster than every beating heart – with 83 ms true temporal resolution and no need for beta-blockers, proven by more than 25 publications. Full cardiac detail at half the dose – down to 2.5 mSv average dose, proven by 5 publications. One-stop shop in Acute Care – fast diagnosis to save time, lives and money, proven by 4 publications. Beyond visualization with Dual Energy – with 10 released applications and Optimum Contrast, proven by 14 publications. etc.

More than 400 SOMATOM Definitions are in clinical use worldwide, not only for daily clinical routine, but also for cutting-edge research. Meanwhile, more than 100 peer-reviewed publications have been released, documenting Dual Source CT, focusing on DSCT´s unique strengths.

Dual Source CT on Scientific Center Stage By Peter Seitz Business Unit CT, Siemens Healthcare, Forchheim, Germany

Seldom does a new technology find its way to a leading role in the world of scientific publications within only a few months. But after Dual Source CT was announced at the RSNA 2005 and made available commercially in summer 2006, it took over center stage almost immediately. In the 2 years since then, more than 100 peer-reviewed articles have already been published. Dual Source CT virtually introduced the topic of Dual Energy CT into most major congresses – and scientific discussions regarding Cardiac CT were brought to a whole new level. This impressive success was crowned by the offer to devote an entire issue of the European Journal of Radiology on Dual Source CT, resulting in 12 new publications featured in the December 2008 issue.

DSCT in Cardiology The foremost capability responsible for this development is, without doubt, the ability of Dual Source CT to utilize 2 X-ray tubes to achieve a true temporal

resolution of 83 ms and thereby, for the first time, allowing robust cardiac imaging without beta-blockers. The clinical effect of this improvement has been best demonstrated by Achenbach et al1 in a randomized study of 200 patients. 100 patients were examined using single source, 64-slice CT and the other 100 with Dual Source CT. Within both sub-groups around half of the patients received oral and intravenous betablockade for a target heart rate ≤ 60 beats/min, whereas the other half did not receive any pre-medication. Results confirmed a clear advantage of Dual Source CT, no matter if the analysis was performed per-patient, per-vessel or persegment. In the case of single source CT, with beta-blockers 91-93% of all studies proved evaluable. Without betablockers this number dropped to 6982%, depending on the analysis approach. On the other hand, imaging with or without beta-blockers didn’t show a significant impact on the number of evaluable patients, vessels or

segments when using Dual Source CT. In all cases results remained above 96%. First studies even suggest that Dual Source CT allows for robust diagnosis of significant stenosis in patients with atrial fibrillation2,3, in the past a common rule-out criteria on single source CT. But while the impact of DSCT on increased temporal resolution is unquestioned, the more robust cardiac CT imaging gets the more it is brought into the spotlight on the topic of radiation exposure. Recently a special focus has been put to the question: What dose values can be reached reliably with a low-dose approach such as a step-andshoot mode? In their study on 120 patients, Scheffel et al.4 from the University of Zurich found that DSCT allows mean effective doses of 2.5 mSv, while 98% of all segments provided diagnostic image quality and 97% of significantly obstructed segments were classified correctly, compared with conventional coronary

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News

angiography. While further improvements on dose reduction are clearly warranted, these results confirm that effective DSCT doses below average diagnostic catheter doses are becoming more and more common.

DSCT in Acute Care A completely different approach is taken by recent publications on DSCT in Acute Care, where, next to clinical effectiveness, economical aspects are considered increasingly important for the everyday question of evaluating patients with suspected acute coronary syndrome. Researchers from the University of Pennsylvania compared conventional approaches, e.g. serial cardiac markers as well as stress testing, with the outcome of an immediate CT coronary angiography5. While the immediate CTA approach was as safe and able to identify as many patients with coronary artery disease as the other approaches, it resulted in the lowest cost and shortest length of stay. Overall, an immediate CTA reduced average costs to $1,240 vs. $2,318 - $4,024.

The average length of stay could be shortened to 8.1 hours vs. 20.9 – 30.3 hours for the other strategies. As the number of CT systems in dedicated emergency department environments is increasing, further studies with larger patient groups are under preparation.

DSCT and Dual Energy Finally, a whole new field of research was opened with the introduction of DSCT Dual Energy, made possible by applying different energy spectra (of 80 kV and 140 kV) to the two X-ray tubes simultaneously. The results are two spiral data sets acquired simultaneously in a single scan providing diverse information that permits differentiation or characterization of the imaged tissue and material. Possible applications are, e.g. an accurate subtraction of bone in CTAs or iodine removal from liver scans to generate a virtual unenhanced image. A brand-new application, the visualization of iodine content in the myocardial blood-pool to diagnose perfusion defects, has just been evaluated by Ruzsics

et al. from Medical University of South Carolina6. They evaluated this approach on 35 patients, and correlated the results with SPECT. Initial results are promising, proving 91% accuracy in comparison with SPECT (per-segment) for detecting any type of myocardial ischemia. In the meanwhile, more than 400 Dual Source scanners have been installed worldwide, generating a rising number of publications on the cutting-edge of CT imaging.

Sources 1 Achenbach S et al. – JACC, VOL 1, NO. 2, Jan 2008. 2 Oncel D et al. – Radiology 2007 Dec; 245(3):70311. 3 Wang Y et al. – Eur J Radiol Nov 2008. 4 Scheffel H et al. – Heart Jun 2008. 5 Chang AM et al. – ACADEMIC EMERGENCY MEDICINE 2008; 15:649-655. 6 Ruzsics B et al. – Eur Radiol 2008 June.

First U.S. Payor Reimburses CT Colonography (CTC) for Screening By Joachim Buck, PhD, Business Unit CT, Siemens Healthcare, Forchheim, Germany

VC has been validated as a screening test for colorectal cancer and detection of large and medium-sized polyps.

According to the ACRIN* 6664 trial, CT Colonography (CTC) – respectively Virtual Colonoscopy (VC) – was comparable to the gold standard colonoscopy for screening intermediate and large-sized polyps. Based on these results, VC has been validated as a screening test for

colorectal cancer and detection of large and medium-sized polyps. Results from other VC trials (IMPACT, Munich Colorectal Cancer Prevention Trial and Wisconsin Trial) have also shown positive results for VC. Thus, the American Cancer Society (ACS) recently added virtual colonoscopy to their new colorectal cancer screening guidelines. This decision is, for the first time, triggering reimbursement for colon cancer screening in the U.S. Colon Health Centers of America (CHC), a provider of VC services for gastroenterology specialists, has signed a contract with Blue Cross Blue Shield of Delaware (BCBSDE). This agreement represents the first major commercial payor

in the United States to reimburse VC screening. BCBSDE has agreed to reimburse CHC of America’s patent-pending, integrated colon screening model, followed by therapeutic colonoscopy for those with discovered polyps. They provide a single, bundled, episode-of-care payment ‘per screening event’. The payor believes that it is essential to have the capability to provide same-day, sameprep therapeutic colonoscopy for patients who need it. This is the first step toward future reimbursements in the U.S. *ACRIN (American College of Radiology Imagin Network).

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The SOMATOM Definition AS 20-Slice Configuration By Jan Chudzik, Business Unit CT, Siemens Healthcare, Forchheim, Germany Since its introduction at RSNA 2007, the SOMATOM® Definition AS, the world’s first adaptive scanner, has already become the fastest selling single source CT in Siemens history with 200 installations worldwide within the first months from market introduction. In its multiple configurations (40-, 64- and 128-slice), it describes another success story for Siemens Healthcare. At this year’s RSNA, the Definition AS platform introduced a further expansion with its new 20-slice configuration attracting the interest of a wide range of healthcare facilities by providing easier and more economical access to the latest innovations of highend CT. This enables a broad spectrum of clinical applications at a great priceperformance ratio. And, with its full,

onsite upgradeability, the 20-slice configuration is able to grow with clinical needs, allowing a continuous expansion of radiology offerings in the future, improving the services for referring physicians and patients. The new SOMATOM Definition AS 20-slice configuration, with its large 31 inch (78 cm) gantry bore, the optional 660 lbs (300 kg) patient weight capacity and its high scan speed, is designed perfectly for high patient throughput, even for obese patients. With this new SOMATOM Definition AS family member, clinicians have access to excellent image quality and clinical capabilities in a very affordable and compact unit, greatly improving patient care.

The new SOMATOM Definition AS 20-slice configuration

4D Noise Reduction: New Filter Setting for Dose Decrease and Image Enhancement By Rainer Raupach, PhD, Business Unit CT, Siemens Healthcare, Forchheim, Germany With the introduction of multi-slice CT making scans with large volume coverage possible, dynamic CT examinations have stepped into clinical routine. With modes like organ perfusion or 4D CT, angiography time series* can be taken, exposing a large part of the body to time-dependent X-rays. Therefore, patient dose has to be considered carefully. 4D image data are routinely acquired by means of multi- or adaptive 4D spiral 1A

1B

scans. Applying a newly developed, elaborate filtering technique, the radiation dose of dynamic CT exams can be reduced by a substantial amount, while retaining equivalent diagnostic information. The procedure is as follows: At a fixed time point, the data from the time series mentioned above are separated into soft contents and sharp edge information, containing the major amount of image noise. By combining the sharp 1 CT perfusion evaluation (blood volume) of the original images (Fig. 1A) and results after image enhancement (Fig. 1B). The number of pixels where perfusion parameters could not be determined due to noise (violet) is significantly reduced.

portion of different time points, the dose can be used more efficiently, thereby leading to an image with significantly reduced noise and improved image quality. The effect of this method can, on the one hand, be utilized to reduce radiation dose while obtaining the same image quality as without 4D Noise Reduction. On the other hand, the spatial resolution of the CT perfusion images can be increased or the reliability of the perfusion parameters improved while maintaining the same dose (Fig. 1). In the perfusion study shown, the perfusion parameters of many pixels cannot be evaluated due to noise (Fig. 1A). Using 4D Noise Reduction mode, these pixels can be reduced, yielding tissue perfusion information with higher quality (Fig. 1B). * Images from a defined body region or organ during a defined period of time.

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The Success Story of the SOMATOM Emotion Continues By Steven Bell Business Unit CT, Siemens Healthcare, Forchheim, Germany In June 2008, the Portsmouth Imaging Centre in Rhode Island installed the 6,000th SOMATOM® Emotion system – making this system the most popular CT in the World. The success of the SOMATOM Emotion continues with installations now heading towards 6,500. “At our new Portsmouth Imaging Centre, we use a Siemens SOMATOM Emotion CT scanner because it provides speed and extremely high resolution that is essential for fast and accurate diagnoses,” said Todd Cipriani, vice president, Professional Services, Newport Hospital.

“Both patients and physicians like knowing that image clarity is excellent.” With the SOMATOM Emotion, the combination of high-end image quality, efficient gantry design, low running costs, high reliability and the smallest installation space requirements, underpin the success. These factors were some of the driving forces behind Newport Hospital’s purchasing decision and the decisions of over 6,000 other SOMATOM Emotion customers.

Simon Shaw (US Product Marketing Manager for SOMATOM Emotion, right) hands a plaque commemorating the 6,000th SOMATOM Emotion installation to David Card (CT/MR Manager, Portsmouth Imaging Center, left).

3D on the fly with new syngo WebSpace 2008B By Christoph Hachmöller, MD Business Unit CT, Siemens Healthcare, Forchheim, Germany Previously, radiologists who were seeking additional reconstructions in coronal, sagittal or other planes to support their diagnosis, needed to call the technologist at the scanner and request them. The technologist then needed to manually start the recon jobs and send the images to the PACS – a time consuming and cumbersome procedure, not to mention the additional amount of data that needed to be archived in the PACS. Now, with the latest functional enhancements of syngo WebSpace 2008B, this annoying work step can be eliminated. The time consuming, traditional “image reconstructions on demand” are being replaced by the interactive “3D on the fly”. With a click on the syngo WebSpace button in the PACS environment, the same case opens in 3D at the very same workplace. The interactive 3D functionality

Image Reconstructions on Demand 1 Auto send images Call for additional image reconstructions 2 3 Manually create and send additional image reconstructions

Interactive 3D on the fly 1 Auto send images

syngo WebSpace

of syngo WebSpace can provide a coronal, a sagittal or any other view on the image data. These views do not need

2 Interactive 3D on the fly

to be prepared beforehand. They are dynamically created on the fly by syngo WebSpace.

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Proactive Tube Failure Prediction: Siemens Guardian Program now Includes TubeGuard for the SOMATOM Definition Family By Ulrike Dräger-Klar and Holger Reinsberger Business Unit CS, Siemens Healthcare, Erlangen, Germany

Hard-down of system

including TubeGuard for the SOMATOM® Definition family is Siemens’ new proactive solution that allows prediction of potential tube and system failure in advance.

k unpredicted tube failure and tube replacement

How does it work?

Reactive service Tube failure – without Siemens Guardian Program™ including TubeGuard Tube break down services request

Continuous Examination

Proactive service – continuous monitoring of various sensor data Tube failure – with Siemens Guardian Program™ including TubeGuard

Scheduled tube exchange triggered by Siemens

Soft-down of system k planned and scheduled downtime

Continuous Examination

CT systems are crucial for clinical diagnosis and important to support emergency processes like trauma patient examinations. Doctors as well as patients are dependent upon the reliable availability of their systems. The CT tube is a component with a usage-dependent life span. It is absolutely vital to system

availability. But a tube can also fail, causing a hard-down of the CT system. This can lead to disruptions of the clinical workflow, and the immediate need for patient rescheduling or transfer to another department. This was the motivation for a new and innovative idea: the Siemens Guardian Program™

Measurement of Cooling Performance measured and calculated lifetime [rel. units] 1,2

proactive triggered tube change

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0 0

20

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140 time [rel. units]

Cooling, vacuum, filament, anode, rotation, focal spot and high voltage all have a significant impact on the operation of the CT tube. Once TubeGuard has been installed, sensors proactively monitor the tube functions via real-time data flow with Siemens Remote Service (SRS) – the efficient and comprehensive infrastructure for medical-equipmentrelated remote services. By doing this, deviations can be detected before problems occur. One example of sensor monitoring is the measurement of cooling performance. The measurement via SRS is based on sensor data of oil temperature, gantry temperature and oil pressure. If the cooling performance falls under defined limits, the tube could possibly fail, Siemens will schedule a tube change at a convenient time for the customer before the failure occurs. This program brings it all together: state-of-the-art technology to assess and transfer information to the Siemens Service Center, expert analysis through our support engineers, and the development of a plan together with the customer to convert system downtime into a planned service visit. With the Guardian Program including TubeGuard, the majority of all tube failures are predicted well in advance, proactively and efficiently.

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1A

1B 1 Biograph mCT (Fig. 1A) offers excellent resolution and contrast in PET•CT imaging, such as in this primary squamous cell carcinoma in the left lung with hilar lymph metastases (Fig. 1B).

Molecular CT – Imaging in Living Colors Siemens Biograph mCT opens doors to earlier disease detection and integrated diagnostics in radiology. By Claudette Yasell, Business Unit MI, Siemens Healthcare, Hoffman Estate, USA

The recent past has seen monumental advances in CT technology, proving the clinical value of multislice capabilities, speed and resolution. But even exquisite CT images can leave unanswered clinical questions and could benefit from the addition of molecular contrast to add metabolic information. Using the most advanced PET (positron emission tomography) technology combined with Siemens adaptive CT technology (known from SOMATOM Definition AS) makes Biograph mCT the crossover scanner that is destined to change the way radiology looks at integrated diagnostics. To move oncology forward, the next innovation in CT should include a “smart” contrast agent. The concept of using molecular contrast with PET and CT has already been applied in the molecular imaging arena with unprecedented success. With this knowledge in hand, together with the increasing demand for PET, asserting that every CT can have molecular imaging capabilities clearly addresses the need for more effective imaging in oncology. Molecular CT makes this technology more

widely available, offering personalized and very specific information about patients’ diseases. Patients will benefit from higher quality diagnostic information that can lead to definitive changes in disease management. Providers could benefit from the potential cost savings from the purchase of one all-encompassing scanner like the Biograph mCT instead of two, a PET scanner and a CT. Biograph mCT was specifically developed for an integrated imaging environment – designed to obtain functional, anatomical and molecular information from one non-invasive diagnostic exam. Using Siemens premium CT technology, it adapts to virtually any patient and clinical need for higher resolution, contrast and speed. Biograph mCT comes in a powerful, small package. It boasts a large bore, short tunnel and a very small footprint for unparalleled patient care and comfort. Biograph mCT is available with up to 128 slices and a table that can accommodate patients up to 500 pounds (227 kilograms). In addition to cutting-edge CT technology, Biograph mCT maximizes the most

advanced PET technology available, including features such as unique PET extended field of view and ultra highdefinition imaging technology with time of flight reconstruction, enabling the possibility of a routine, five-minute PET scan. It offers the ultimate in PET image quality and count rates for faster, more comprehensive scanning, and provides maximum patient comfort and workflow efficiency. Latest applications in oncology from CT and PET include the ability to delineate target volumes for diagnosis, staging and re-staging of cancer, providing exquisite anatomical detail plus a measurement of cell metabolism. Future functionalities may include correlation of information about organ perfusion derived from CT and tumor metabolism derived from PET. Physicians as well as patients will benefit from the valuable information provided by molecular CT.

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As Radiation Dose Goes Down, Attractiveness of CT Rises In recent years, Siemens scanners have steadily decreased radiation dose in CT exams, making CT use in everyday diagnostics all the more interesting. Now, for example, cardiac CT can be performed with doses as low as the “gold-standard”, cardiac catheterization and below, as studies at the University Hospital Zurich have shown. By Oliver Klaffke

Hatem Alkadhi, MD, radiologist and associate professor at the University Hospital Zurich, is excited. Together with his colleagues he performed tests on patients with cardiac computed tomography (CT) utilizing two of Siemens newest high-end scanners, the SOMATOM® Dual Source Definition and the SOMATOM Definition AS. The radiation doses required were no higher than cardiac catheterization or scintigraphy. “This opens totally new perspectives for cardiac diagnostics with CT,” Alkadhi says. “Excellent images and low dosage is what physicians have always wanted,” he adds.

His findings are in line with the general trend in CT in recent years. The radiation dose needed for reliable diagnoses was considerably reduced when Siemens, the leader in the field of CT, pushed the frontier of progress forward with new Siemens dose-saving technologies such as the Adaptive Dose Shield, CARE Dose4D, ECG-Pulsing and Adaptive Cardio Sequence that are used today to deliver optimal images with as low dosage as possible. This, of course, is of great benefit for patients. “Dosage is always an issue, especially for children and patients who need a number of consecutive CTs,” says Prof. Borut

Marincek, MD, head of radiology at the University Hospital in Zurich. “For the sake of our patients, we will always opt for the latest technology that offers the best results with the lowest possible dosage,” he says. This was one of the main reasons why he and the hospital decided to purchase two Siemens highend CT scanners, the Dual Source SOMATOM Definition and the SOMATOM Defintion AS. Both of them provide unique technologies to significantly reduce patient exposure in both clinical routine and advanced applications and, therefore, assure better patient care.

Economic benefits of using CT

“Excellent images and low dosage is what physicians have always wanted.” Hatem Alkadhi, MD, Radiologist and Associate Professor, University Hospital Zurich

In addition to the main health issues criteria such as dose reduction, there are significant financial reasons for investing in CT. This is especially true for cardiac diagnostics. ”Through the increased use of CT for cardiac diagnostics, a large hospital can clearly reduce costs,” says Marincek. The increased use of computed tomography has a great number of advantages for hospitals. “With a stronger emphasis on CT, it’s possible to save on expensive investments for the procurement and maintenance of various other equipment that, so far, has been primarily used for diagnostics,” he points out.

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“ Dosage is always an issue, especially for children and patients who need a number of consecutive CTs.” Prof. Borut Marincek, MD, Head of Radiology, University Hospital Zurich

For his department at the University Hospital in Zurich, Marincek calculates that CT represents lower procurement and infrastructure costs than an additional gamma chamber or further installations for cardiac catheterization testing. His conclusion: “The costs of the individual tests are much lower with CT than with the other procedures.” As in other fields of CT, the dosage needed in cardiac diagnostics can now be kept very low. “Radiation exposure is no longer a reason to refrain from using CT for cardiac testing,” asserts Alkadhi. The Zurich-based physicians completed their tests using very low doses. On average, only 2.5 mSv were required to obtain high-quality, meaningful images. As a result, the radiation exposure remained well under the values that have previously been typical with CT-Angiography. Depending on the test conditions, these have ranged between 9 and 21 mSv. “The radiation doses of our tests are below those currently necessary with cardiac catheterization,” says Alkadhi. He and his colleagues applied CT to 120 patients suspected of coronary heart disease. They were able to obtain diagnostically valuable and unrivaled data at minimal radiation exposure.

This was possible as the result of technical advances in Siemens’ CT technology and through the development of intelligent software applications for CT. The tests in Zurich used the Siemens SOMATOM Definition, a CT equipped with two X-ray tubes functioning simultaneously. “It is a significant advancement that dose can be kept so low using for example the step-and-shoot procedure,” says Alkadhi. This and also other new features, such as the Adaptive Dose Shield, are implemented as well in the SOMATOM Definition AS, offering dose reduction in every spiral exam. This means that the patient is not subjected to radiation not needed for the diagnosis. “Using the lowest possible dose is of definite benefit to the patient,” Alkadhi says. Because computed tomography technology will surely be more frequently used in the future, dose reduction becomes a more compelling issue. This is one of the reasons Zurich University Hospital always opts for the latest technology in computed tomography. It should not be assumed that dose reduction has been accomplished only in this area. Such Siemens innovations are used today to deliver optimal images with as low dosage as possible. All together, they bring CT into the

mainstream of clinical routine making the SOMATOM Definition and the SOMATOM Definition AS scanners intelligent buying decisions. “With future purchases, dose will be one of the most important criteria when deciding in what system to invest,” Marincek says.

Oliver Klaffke is a science journalist in Switzerland.

“With future purchases, dose will be one of the most important criteria when deciding in what system to invest.” Prof. Borut Marincek, MD, Head of Radiology, University Hospital Zurich

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Business

Making a Case for the SOMATOM Emotion The long list of benefits reported by the staff at Northside Hospital in Atlanta, Georgia, since five new SOMATOM Emotion scanners were installed in January 2008 reads like a testimonial – from exceptional images and increased throughput to patient satisfaction and financial benefits. By Sameh Fahmy

“16-slice is a configuration that offers all the necessary protocols and offers them efficiently and with good diagnostic capabilities.” Carolyn J. Weaver, MD, Radiologist at the Northside Hospital in Atlanta

With 14 imaging facilities spread across a large metropolitan area, Northside Hospital in Atlanta, GA, needed a CT solution that would reliably and efficiently allow its staff to image a large volume of patients with a broad range of medical needs. “Our goal is to make sure that our healthcare is convenient and patient focused, while also providing our referring physicians with high-quality imaging, regardless of location,” says director of radiology services Deidre Dixon. Northside originally had a variety of single-, four- and six-slice CT scanners at its facilities and sought to upgrade with a solution that would provide superior image quality, rapid workflow, and maximum return on investment. In January 2008, after a collaborative decision process, they chose to install five Siemens SOMATOM® Emotion CT scanners. As a result, Northside has been able to expand its imaging services while gaining efficiencies and measurable financial benefits from faster workflow. “We were looking for a workhorse scanner,” says radiologist Carolyn J. Weaver, MD, “and the SOMATOM Emotion has proven to be just that.”

The 16-Slice Choice Weaver says the hospital’s previous scanners limited the protocols that Northside could offer at some locations. “Configurations greater than 16 slices allow for cutting-edge applications,” she says, but Northside needed a scanner that could

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“Our goal is to make sure that our healthcare is convenient and patient focused, while also providing our referring physicians with high-quality imaging regardless of location.” Deidre Dixon, Director of Radiology Services at the Northside Hospital in Atlanta

capably handle their day-to-day needs. “For basic outpatient scanning, 16-slice is a configuration that offers all the necessary protocols and offers them efficiently and with good diagnostic capabilities,” Weaver says. In addition to superb image quality, Northside wanted a system that would efficiently handle its large volume of CT procedures. In 2007 alone, Northside performed more than 78,000 CT exams. The expansion of services after installation of the SOMATOM Emotion 16 systems has also resulted in a financial benefit to the group by increasing patient volumes. One imaging center, for example, increased patient capacity by 71 percent after upgrading from a single-slice scanner to the SOMATOM Emotion 16. The ability to expand services and increase throughput aren’t the only features that boost return on investment. Another reason is that the SOMATOM Emotion has an economical price/performance ratio and minimum lifecycle costs. The SOMATOM Emotion has the industry’s lowest power supply demand, requiring 70 kVA versus 90 to 100 kVA for other vendor’s 16-slice scanners. Its low heat dissipation of less than 6.8 kW also reduces cooling costs compared to competition.

Fast Installation and Minimal Down Time Northside Hospital clearly isn’t alone in choosing the SOMATOM Emotion. As

of July 2008, more than 6,000 customers have installed the system, making it the most popular CT scanner in the world. In many cases the SOMATOM Emotion can be installed in only three days while, in contrast, many other scanners require more than a week to install. Longer installation results in greater patient rescheduling and inconvenience. The ease of installation is facilitated by the remarkably small, 18 square meter (194 cubic feet) footprint of the system. Weaver says the compact gantry design also creates a more relaxing environment for patients. “Anytime a patient sees something that is overwhelming in size, particularly in proportion to the room it’s in, it creates anxiety,” Weaver says. “And that could make it more difficult to get an IV and make the whole experience more difficult.” Downtime can be costly for hospitals, but Dixon points out that it is also a major inconvenience for patients. “If a patient has taken a day off work to have a CT and comes in to find that there’s a machine issue, it not only impacts us but, subsequently, also the patient,” Dixon says. “Even if we’re able to get the machine up that same day, we’re left with customer dissatisfaction.” The SOMATOM Emotion was built with reliability in mind, and has not disappointed the staff at Northside. “We’ve never had any problems with it since we’ve had it here,” says radiology supervisor Reginald Moultrie. “It’s great.”

Advice to Other Facilities With their purchase behind them, administrators and technicians at Northside Hospital are now realizing the benefits of a decision that was truly collaborative. Dixon recommends visiting many sites and asking users about downtime and how well scanners perform day-to-day. Image quality must meet the expectations of radiologists, and she recommends choosing one vendor so that technologists can easily share information and support each other. The amount of support a vendor offers in optimizing applications is important, too, she says. “We feel that partnership is a key component of the vendor selection process,” Dixon says. “We want to feel that the vendor has knowledge of our core business strategy and based on that knowledge can suggest products that fit within our organization to make sure patients receive the best care possible. We’re very pleased with our collaborative relationship with Siemens.”

Sameh Fahmy, is an award-winning freelance medical and technology journalist based in Athens, Georgia, USA.

Further Information www.siemens.com/somatomemotion

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Business

syngo WebSpace: Command Central for Fast and Efficient Image Processing In a recent interview with SOMATOM Sessions at the Hospital Notre-Dame in Tournai, Belgium, Jacques Kirsch, MD, head of the Department of Radiology, shared his insights on the impact of syngo WebSpace on his facility’s diagnostic capabilities and workflow processes. By Rita Wellens, PhD

“The essential workflow advantage of syngo WebSpace is centralizing and making available all diagnostic solutions from any workplace.” Jaques Kirsch, MD, Head of the Department of Radiology, Hospital Notre-Dame, Tournai, Belgium

Jaques Kirsch, MD, reading at his integrated PACS / syngo WebSpace workplace of the Hospital Notre-Dame.

syngo WebSpace is the latest innovation in client-server solutions for image processing. Any personal computer or laptop is turned into a diagnostic command center when linked up with syngo WebSpace. It allows for real-time access to image data – from anywhere*.

Radiology Department with Cutting-Edge Technology The Hospital Notre-Dame is a general

hospital located in the city of Tournai, about 85 kilometers southwest of Brussels. The hospital provides – considering its size, with 300 acute hospital beds – a respectable spectrum of radiological services and is equipped with state-of-the-art technology. The radiology department covers the entire spectrum of conventional radiology and CT. This includes very sophisticated computed tomography such as cardiac CTA and CT

colonography. In addition, many CT interventions, especially for pain therapy, are performed in the department. The radiology department operates a SOMATOM Definition Dual Source CT scanner and a SOMATOM Definition AS scanner. The latest innovation in the department of radiology is the syngo WebSpace client-server solution, which the head of the department, Jacques Kirsch, MD, uses together with four staff radiologists.

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Business

Easy Access to Image Data – Everywhere

Interactive 3D for Referring Physicians

The obvious benefit that Kirsch enjoys while using syngo WebSpace is the fact that many time-consuming steps have been eliminated, especially for the manipulation, retrieval and distribution of thin-slice CT data. The radiologist no longer has to walk to his 3D workstation, and patient data no longer has to be physically moved to another location for accessing at a particular workstation. In addition, everyone always knows where to find the thin-slice data sets: on the syngo WebSpace server. “The essential workflow advantage of syngo WebSpace is centralizing and making available all diagnostic solutions from any workplace,” Kirsch emphasizes. ”The fact that syngo WebSpace allows the transfer of reconstructed thin-slice CT volume data to the central server in real time offers radiologists the unique possibility of accessing the complete patient CT imagery – thick and thin slices – from any connected workstation, and to have all of the software wizardry at hand. This immediate availability of CT images speeds up workflow and strengthens diagnostic capabilities as well as intervention planning. Multiple users can in parallel access 3D diagnostics and may even hold 3D interactive sessions through the internet.” Of course, thin-slice data was already being used by the radiologists before syngo WebSpace was in place, for example, to evaluate very small lesions. However, another dedicated thin-slice server had to be used to temporarily – eight to nine months – store the large-volume thin-slice CT data. syngo WebSpace has clearly done away with the previously existing restrictions tied into scanners and their networking. “We do not need to switch to another workstation or room – we have everything right at our fingertips. In other words, once syngo WebSpace was connected to the network, it started functioning as a ‘central dispatch.’ syngo WebSpace is totally integrated into PACS – I rate that as a feat of genius,” Kirsch says.

Kirsch explains this syngo WebSpace advantage while beaming up 3D images at the PACS console: “In pre-syngo times, the diagnostic reconstructions of thick slices would be transmitted through the central PACS and thus would be available to all clinicians.” Radiologists performed 3D reconstructions at a separate workstation. When the pathology was obvious in the 3D image, they created a screenshot and sent it back to the PACS. Other clinicians could retrieve and review only this screenshot, which of course could no longer be manipulated. “Totally new is not having to forward clinicians those flat, static images anymore,” says Kirsch. “Thanks to syngo WebSpace, we can send real-time, dynamic volumes! This is truly a spectacular innovative feature. Typically – pre-syngo WebSpace – only radiologists worked with volumes, and clinicians worked with images. Now, clinicians have full access to the fascinating world of volumes.” Radiologists working in 3D on syngo WebSpace can save a bookmark when the pathology becomes obvious on the screen. Later other clinicians just need to click the bookmark in “their” syngo WebSpace environment and immediately get the same image that the radiologist prepared for them. They now have an interactive 3D image. The difference is that the clinician can further manipulate the image in order to get a better understanding of the pathology. One can think about a comminuted fracture. The orthopedic surgeon highly appreciates the ability to turn the fracture around to get an estimation of the spatial situation of the bone fragments.

consuming and cumbersome procedure. Not to mention the additional amount of data that needed to be archived in the PACS. With syngo WebSpace this annoying work step can be almost entirely eliminated. The time-consuming traditional “recons on demand” can be replaced by the interactive “3D on the fly.” With a click on the syngo WebSpace button in the PACS environment, not only the same case and the same image series open in 3D at the very same workplace, but additionally, each data set can now be presented in an individual, pre-defined screen layout which contains the planes to display such as coronal, sagittal or any other plane, as well as the favorite hanging protocols and window settings. Kirsch adds that being able to share these incredibly fast diagnostic capabilities with colleagues anywhere has boosted overall efficiency, patient care and staff satisfaction. In order to size up the positive impact of syngo WebSpace as suggested by the many superlatives he uses to describe it, Kirsch is asked whether he could envision operations at his department now without the syngo WebSpace solution. He sighs heavily and answers, “It would be very, very difficult – such a huge step backward! syngo WebSpace has facilitated so many aspects of our work. It has seamlessly integrated with PACS and other existing IT applications, and it has given us such diagnostic flexibility. Not being able to use this resource anymore is quite unthinkable.” Even after such a short period of time in routine use, syngo WebSpace’s impact is already being felt in countless positive ways at the Hospital Notre-Dame.

on the fly Recons

*internet connection required.

So far, radiologists who were seeking additional reconstructions in coronal, sagittal or other planes to support their diagnosis, needed to call the technologist at the scanner and ask for additional reconstructions. The technologist needed to manually start the recon jobs and then send the images to the PACS – a time

Rita Wellens, PhD, is a medical writer and clinical research consultant residing in Belgium.

Further Information www.syngo-webspace.com

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Clinical Results Cardiovascular

Case 1 Coronary CTA with Flash Spiral Scanning in 300 msec Scan Time By Stefan Achenbach, MD* and Andreas Blaha** * **

Department of Cardiology, University of Erlangen-Nuremberg, Erlangen, Germany Business Unit CT, Siemens Healthcare, Forchheim, Germany

HISTORY A 58-year-old male patient with atypical chest pain and a family history of premature coronary artery disease was referred to the cardiology department to rule out coronary artery disease. Coronary CT-Angiography (CTA) was performed with a Dual Source CT in low dose technique using prospective

DIAGNOSIS triggering in combination with Flash Spiral Cardio. This new heartbeatcontrolled scan mode allows ultrafast spiral acquisition as a direct result of having 2 X-ray tubes, simultaneously collecting information. The entire scan was acquired in just 300 ms.

1

After determination of the contrast transit time using a test bolus approach, coronary CTA was performed in craniocaudal direction after injecting 60 ml iodine contrast agent followed by a 50 ml saline chaser, both at 6 ml/s. The mean heart rate of the patient was 52 beats per minute, which allowed

2

Neurology Clinical Results

1 Volume Rendered Image of the heart shows artifact free course of the right coronary artery (RCA) including side branches.

2 Zoomed VRT of left main coronary artery (LM, white arrow) including left circumflex (LCX, blue arrow) and left artery descending (LAD, green arrow).

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Cardiovascular Clinical Results

3A

3B

3C

3D

3E

3 Curved Planar Reformation (CMPR) of the RCA. A series of crossectional reconstructions of the artery shows no lumen narrowing; only minor calcified plaques proximal.

COMMENTS for a particularly sharp visualization of the coronary tree. Tube voltage was set at 100 kV, with a tube current of 280 mAs, which resulted in a very low dose of 0.9 mSv. Coronary vessels were visualized free of artifacts. The left anterior descending coronary artery (LAD) and the right coronary artery (RCA) showed minor calcified and non-calcified plaques without lumen narrowing. The left main coronary artery (LM) and left circumflex coronary artery (LCX) did not show any abnormalities.

Scanning with Flash Spiral Cardio allowed accurate and artifact-free visualization of the coronary arteries in one ultrafast acquisition of 0.3 seconds. The Flash Spiral Cardio scan mode combined with the simultaneously working two X-ray tubes results in significantly faster scan time, reducing the applied dose to the patient.

The RCA and LAD revealed minor calcified plaques and non-calcified plaques without vessel stenosis. No further diagnostic method was needed to determine an adequate diagnosis for the patient. The new scan mode allows to rule out coronary stenosis at an extremely low dose, making further diagnostic assessment unnessesary.

EXAMINATION PROTOCOL Scanner

Flash Spiral mode

Scan area

heart

Spatial resolution

0.33 mm

Scan length

138 mm

Slice width

0.6 mm

Scan time

300 ms

Reconstruction increment

0.5 mm

Scan direction

cranio-caudal

Reconstruction kernel

B26f

Heart rate

52 bpm

Contrast

Tube voltage

100 kV

Volume

60 ml

Tube current

280 mAs/rot.

Flow rate

6 ml/s

Dose

0.9 mSv

Start delay

26 s

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Clinical Results Cardiovascular

Case 2 Low Dose Coronary CTA Reveals High Grade Stenosis By Stefan Achenbach, MD Department of Cardiology, University of Erlangen-Nuremberg, Erlangen, Germany

HISTORY

1

A 38-year-old female patient with a history of former nicotine abuse, arterial hypertension, and family history of premature coronary artery disease, hyperlipidemia, and apoplectic stroke was referred to the Cardiology Department with atypical chest pain to rule out coronary artery disease. Coronary CT-Angiography (CTA) was performed with a SOMATOM Definition Dual Source CT in low dose technique using prospective triggering (Adaptive Cardio Sequence), with a temporal resolution of 83 ms and spatial resolution of 0.33 mm.

2

1 VR visualization of the left circumflex (LCX) artery shows the stenotic segment (arrow).

2 syngo Circulation provides angiographic like view of the entire heart.

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Cardiovascular Clinical Results

DIAGNOSIS After determination of the contrast transit time using a test bolus approach, coronary CT-Angiography was performed in cranio-caudal direction injecting 75 ml of iodine contrast agent followed by a 50 ml saline chaser, both at 6 ml/s. Due to the relatively low heart rate of 50 bpm, a sequential scan was chosen. Tube voltage was set at 100 kV, with a tube current of 215 mAs, which resulted in a very low dose (1.6 mSv). Total scan time was 8 seconds. Coronary vessels were visualized free of artifacts. The left circumflex coronary artery (LCX) revealed a high grade stenosis. The left anterior descending coronary artery (LAD) and the right coronary artery (RCA) showed no relevant plaques or stenosis.

3

4A

COMMENTS SOMATOM Definition Dual Source CT allowed accurate and artifact-free visualization of LM, LAD and RCA without showing any stenosis or plaques, while a high grade stenosis was demonstrated in the left circumflex coronary artery, at a total dose of 1.6 mSv. The patient was referred to the angiography suite for revascularisation of the circumflex artery by percutaneous coronary intervention (PCI).

3 Multi Planar Reformation (MPR) of left circumflex artery (LCX) and a crossectional view of LCX.

4A Conventional angiography prior to percutaneous coronary intervention (PCI).

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

heart

Scan length

104 mm

Scan direction

cranio-caudal

Scan time

8s

Heart rate

50 bpm

Tube voltage

100 kV

Tube current

215 mAs

Dose

1.6 mSv

Spatial resolution

0.33 mm

Rotation time

0.33 s

Slice collimation

0.6 mm

4B

4B Conventional angiography after PCI.

Reconstructed slice thickness

0.75 mm

Increment

0.6

Kernel

B30f

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Clinical Results Cardiovascular

Case 3 Dual Source CT: Pediatric Congenital Heart Disease By Suzu Kanzaki, MD, Masahiro Higashi, MD, Hiroaki Naito, MD, PhD Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan

HISTORY A 10-day-old newborn was referred to the pediatric cardiology department for treatment of his congenital heart disease. Examination by transthoracic echocardiography led to a diagnosis of right isomerism, complex cardiac type of total anomalous pulmonary venous

1A

connection with obstruction, double outlet right ventricle with complete atrioventricular septal defect, coarctation of the aorta and bilateral superior vena cava. An ECG gated cardiac Dual Source CT scan was taken to help confirm the diagnosis.

The patient’s height was 43.5 cm, body weight was 2.4 kg, and mean heart rate during the scan was 142 bpm. Due to the fast scan time of only 3 seconds, he had to be sedated only by oral medication before the scan.

1B

1 Volume rendered display of the pediatric cardiac scan reveals aortic coarctation (Fig. 1A) and a complex cardiac type of anomalous pulmonary venous connection even at a mean heart rate of 142 bpm (Fig. 1B).

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Cardiovascular Clinical Results

2A

2B

40 mm 20 mm

2 Maximum Intensity Projection (MIP) of the aortic coarctation (Fig. 2A) and double outlet right ventricle (Fig. 2B).

DIAGNOSIS

COMMENTS

The aortic coarctation and the anomalous pulmonary venous connection to the abnormal site of the atrium are shown in the DSCT (Dual Source CT) images above. DSCT could confirm the morphologies of these great vessels, which were difficult to discern by echocardiography alone. The morphology of the cardiac chambers was also well detected as diagnosed by echocardiography. Based on these findings, palliative surgical correction was planned.

The Dual Source CT images were of diagnostic quality despite the small size of the patient’s heart and despite his high heart rate of 142 bpm. The patient could not hold his breath, but scan time was short enough to suppress the influence of banding artifacts. The high CT im-

age quality made precise surgery planning possible. This scan was performed shortly after installation of the Dual Source CT at the radiation center. With more experience, it’s possible to reduce the dose to pediatric patients by about 2/3.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

thorax

Scan length

80 mm

Scan time

3s

Scan direction

cranio-caudal

Tube voltage

100 kV

Tube current

280 mAs

Rotation time

0.33 s

Spatial resolution

0.33 mm

Slice collimation

0.6 mm

Reconstructed slice thickness

0.6 mm

Increment

0.5 mm

Kernel

B25f

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Clinical Results Cardiovascular

Case 4 Identification of Vessel Stenosis of the Lower Leg by Dynamic CT-Angiography Using the SOMATOM Definition AS+ By Wieland H. Sommer, MD and Konstantin Nikolaou, MD Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

HISTORY A 82-year-old man presented with peripheral occlusive disease. A previous occlusion of his left superficial femoral artery had been treated by a femoropopliteal bypass. A second bypass became necessary after occlusion of the first. The patient now presented with an advanced stage of disease with rest pain of his left lower leg and foot

(Fontaine stage III). He was referred to our radiology department to undergo imaging of the vessels of the lower extremity.

1A

1B

DIAGNOSIS Performing a standard peripheral run-off CT-Angiography, significant disease in

33 s* 1C

40.5 s* 1D

45.5 s* 1

50.5 s*

Contrast enhancement of the lower leg at different points of time. The initial enhancement of the left and right lower leg differs by 12.5 seconds. Without the venous overlay, it can be seen, that only the fibular artery is contrasted in the left lower leg.

the proximal parts of the lower extremity and stenotic or occluded bypass vessels may lead to asymmetric contrast enhancement of the lower leg, which may cause a reduced diagnostic accuracy in the region of the calf, either by insufficient contrast enhancement of one side or by venous overlay of the contralateral side. To overcome this problem, an additional time-resolved CT-Angiography of the lower leg can be performed before the standard lower-extremity run-off. In the time-resolved examination, we cover a range of 27 cm including the distal popliteal artery, the trifurcation and the proximal part of the three arteries of the lower leg. Twelve phases are used, one every 2.5 seconds. This enables a clear depiction of the contrast dynamics and there will always be a truly arterial phase on either side that is perfect for diagnostic purposes. In this patient, the standard peripheral CTA protocol, covering the peripheral run-off from the renal arteries down to the feet, proved that the femoro-popliteal bypass on the left side was not occluded. The right superficial femoral artery showed no significant stenosis, but was rather aneurysmatic. However, in the standard lower-extremity run-off, the contrast enhancement of the lower leg was asymmetric. On the left side, venous overlay made an evaluation of the calf arteries difficult. On the right side, the lower leg was not yet sufficiently contrasted. Adding the dynamic information of the

*After contrast media injection.

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Cardiovascular Clinical Results

time-resolved CTA revealed an asymmetric enhancement of the lower leg. The initial enhancement of the left and right popliteal artery differed by 12.5 seconds. On the left side, only the fibular artery was continuous, while the other two vessels were not contrasted. On the right side, the anterior tibial artery only showed proximal enhancement and was then occluded in the distal vessel segments.

2A

2 VRT of lower extremity run-off: The aneurysmatic right superficial femoral artery leads to a delayed contrast enhancement of the right lower leg. While the left lower leg already shows venous overlay, the right side is not sufficiently contrasted.

2B

COMMENTS In case of asymmetric proximal stenosis or bypass grafts, the dynamic of the blood flow of the lower leg may be influenced such that at the time of image acquisition, vessels of one side are not yet enhanced or the other side shows venous overlay. This problem can be overcome by dynamic CT-Angiography, using multiple phases in image acquisition. A further advantage of dynamic CT-acquisition is the evaluation of stenosis. Especially in patients with peripheral arterial disease, multiple confluent or circular calcifications make it difficult to estimate the residual lumen. The time-resolved information of the arterial enhancement provides additional information for radiologists and vascular surgeons. In patients with peripheral arterial disease, therefore a first dynamic scan covering the lower leg was performed including the lower popliteal artery, the trifurcation and the proximal and middle portions of the fibular artery, as well as the anterior and posterior tibial artery. In order to lower the radiation exposure the range was limited to 27 cm and the tube current and the tube voltage were lowered to 165 mAs and 80 kV, respectively. Dynamic CT-Angiography, as it is rendered possible by the SOMATOM Definition AS+, is therefore a helpful tool for the evaluation of the lower leg arteries in patients with known peripheral occlusive disease.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition AS+ CT-Angiography

SOMATOM Definition AS+ Adaptive 4D Spiral

Scan area

run-off

lower leg

Scan length

1335 mm

270 mm 12

Scan phases Scan time

27 s

Scan direction

cranio-caudal

25 s cranio-caudal

Tube voltage

120 kV

80 kV

Tube current

130 mAs

165 mAs

Dose modulation

CARE Dose4D on

CARE Dose4D off

Rotation time

0.5 s

0.3 s

Pitch

0.6

Adaptive 4D Spiral

Slice collimation

0.6 mm

0.6 mm

Slice width

0.75 mm

1.5 mm

Reconstruction increment

0.5 mm

1 mm

Reconstruction kernel

B20f

B30f

Volume

100 ml

50 ml

Flow rate

5.0 ml/s

5.0 ml/s

Post processing

syngo InSpace 4D

syngo InSpace 4D

Contrast

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Clinical Results Oncology

Case 5 SOMATOM Definition Dual Energy Scanning: Liver Imaging with Optimum Contrast By Satoru Kitano, MD, Nagaaki Marugami, MD, Toshiaki Taoka, MD, PhD, Kimihiko Kichikawa, MD, PhD Department of Radiology, Nara Medical University, Nara, Japan

HISTORY

DIAGNOSIS

COMMENTS

A 55-year-old male was referred for a Dual Source CT follow-up scan after transcatheter arterial chemoembolization (TACE) of his hepatocellular carcinoma (HCC) 6 years ago. A contrast enhanced, dynamic CT scan of the abdomen was performed on the SOMATOM Definition using Spiral Dual Energy for screening for recurrences after chemoembolization.

The hepatic arterial-dominant phase images revealed numerous hyper-attenuating lesions (Fig. 1B). In the virtual non-contrast image, the lesions showed almost iso-density with the liver parenchyma (Fig. 1A). From syngo Dual Energy (DE) Optimum Contrast images – improved even more after post-processing – a clear analysis of the visible lesions was possible (Fig. 1C). The patient was then diagnosed with multiple HCC recurrence with liver cirrhosis.

In the Dual Energy mode, two X-ray sources can be operated simultaneously at different kV levels: 140 kV/80 kV. The results are two spiral data sets acquired in a single scan, providing diverse information that allows one to differentiate, characterize, isolate, and distinguish the imaged tissue and material. Enhanced patterns of liver lesions can be visualized with the syngo Dual Energy Liver VNC (Virtual NonContrast) application. With the VNC-mode,

1A

1B

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Oncology Clinical Results

any contrast-medium generated contrast disappears, with the remaining images indicating just tissue related differences (Fig.1A). The standard mixed view shows iodine-contrasted structures (light-col-

ored) against non-contrast enhanced structures (dark-colored) (Fig. 1B). With Optimum Contrast, an image that combines the high contrast of the 80 kV image and the low noise of the mixed image can

be generated (Fig. 1C). Optimized differentiation of contrasted and non-contrasted regions allows an even more detailed and clearer diagnosis compared to the standard mixed view.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

Abdomen

Slice collimation

0.6 mm

Scan length

268 mm

Slice width

1 mm

Scan direction

cranio-caudal

Reconstruction increment

0.5 mm

Scan time

10 s

Reconstruction kernel

30 D

Tube voltage A/B

140 kV/80 kV

Contrast

Tube current A/B

80 Eff. mAs/345 Eff. mAs

Volume

100 ml

Dose modulation

CARE Dose4D on

Flow rate

3 ml/s Iodine 370 mgl/ml

Rotation time

0.5 s

Postprocessing

syngo DE Virtual Unenhanced

Pitch

0.8

1C

Bolustracking

1 Virtual Non-Contrast mode: any contrast-medium generated contrast disappears with the remaining images indicating just tissue related differences (Fig. 1A).

Standard mixed view: shows iodine-contrasted structures against non-contrast enhanced structures (Fig. 1B). Optimum contrast: an optimized noise-to-contrast ratio can be reached, resulting in clearer and better contrasted image quality (Fig. 1C).

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Clinical Results Oncology

Case 6 Lung Parenchyma Analysis Software with Automated Three-Dimensional Quantification of Emphysema By Myrna C.B. Godoy, MD and David P. Naidich, MD Department of Radiology, New York University Medical Center, New York, USA

HISTORY A 72-year-old male, a former smoker on home oxygen with history of severe COPD, was referred for a DSCT scan of the thorax for follow-up due to worsening dyspnea. The patient had bilateral upper lobe lung volume reduction surgery 8 years ago.

DIAGNOSIS The DSCT scan with lung window setting showed diffuse severe emphysema and bullous changes were identified throughout the upper lobes. Severe centrilobular emphysema was also identified including the lower lobes (Fig.1A). Surgical clips and architectural distortion from prior bullectomy were noted in the upper lobes. syngo InSpace Lung Parenchyma Analysis software was then used to quantify the amount of emphysema, characterized by lung attenuation below -950 HU1. Results were stratified by lung thirds (upper, middle and lower) to evaluate the distribution of the disease. As illustrated in Figs.1B and 1C, the software allowed the automatic three-dimensional quantification of total lung volume and relative volume percentages, mean lung density, and low and high attenuation volumes. The low attenuation volume (LAV) corresponds to the volume of emphysematous lung and is displayed as a percentage of the total lung volume. In this case, the analysis showed that 51.5% of the left lung and 38.4% of the right lung volume corres-

ponded to emphysema (Fig. 1C, arrows). It also confirmed the upper lobe predominance of the disease. Emphysema cluster analysis was automatically performed, showing clusters class 1 (> 2mm3), class 2 (> 8mm3), class 3 (> 65mm3), and class 4 (>187mm3) colored in blue, green, yellow, and red, respectively (Figs. 2A-B). The vast majority of the emphysema in this patient was classified as cluster class 4, which involved 50.3% of the left lung volume and 37.0% of the right lung volume (Fig. 2C).

COMMENTS The syngo Lung Parenchyma Analysis software enables automated evaluation of emphysema. It permits not only precise quantification of the amount of disease, but also classification of the foci of emphysema by size and distribution of the disease. The importance of these parameters resides in the preference for accurate quantification of disease when compared with routine pulmonary functional testing for assessing potential therapeutic options in patients with emphysema. While characterization of large bullae indicates the possibility of treatment with bullectomy, in fact, most patients present with either predominant centrilobular or panlobular emphysema. Over the past several years, a number of innovative therapeutic options have been developed for treating patients with predominant upper lobe centrilobular em-

physema. In addition to routine lung volume reduction surgery (LVRS),2,3 newer interventional bronchoscopic techniques have emerged as potential alternatives, including the placement of one-way endobronchial valves and bronchial fenestration.4,6 As emphasized in this case, in addition to preoperative evaluation, it is equally important to monitor disease progression following surgery. For this purpose, quantitative CT offers a potential alternative to less precise measurements of disease severity, including routine exercise testing and PFTs. In addition, CT allows identification of potential complications (including the development of lung cancer in this especially predisposed population). In this regard, the availability of a “user-friendly” CT application will be of critical importance in establishing quantitative CT as the gold standard for both pre- and post-operative assessment of patients with emphysema. In this case, the degree of residual emphysema following lung volume reduction surgery established this patient as a candidate for lung transplantation.

References 1 Gevenois PA et al. Am J Respir Crit Care Med 1996; 154:187-192. 2 Lederer DJ et al. Clin Chest Med 2007; 28:639653, vii. 3 Fishman A et al. N Engl J Med 2003; 348:20592073. 4 Wan IY et al. Chest 2006; 129:518-526. 5 Reilly J et al. Chest 2007; 131:1108-1113. 6 Cardoso PF et al. J Thorac Cardiovasc Surg 2007; 134:974-981.

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Oncology Clinical Results

1A 2A

1B

1C

1 Lung parenchyma analysis: general analysis stratified into upper, middle and lower lung thirds. Axial CT scan at the level of the carina showing severe emphysema with bullous changes in the upper lobes and centrilobular emphysema in the superior segments of the lower lobes (Fig. 1A). Histogram showing severe emphysema bilaterally with upper third predominance in both lungs (Fig. 1B). Quantitative three-dimensional analysis of lung volume, mean lung density, low and high attenuation volumes are displayed (Fig. 1C). The low attenuation volume (LAV %) indicates the percentage of the lung with emphysema.

2A

2B

2C

2 Lung Parenchyma Analysis: Cluster classification stratified by thirds in the left and right lung. Axial and coronal reformats (Figs. 2A-2B) showing emphysematous clusters, color-coded by size. The red color corresponds to the largest clusters (Class 4, ≥ 187 mm3). Results displayed in the table (Fig. 2C) show the percentage of lung volume involved by specific cluster’s size. In this case there is severe emphysema characterized by Class 4 clusters involving 50.3% of the left lung volume and 37% of the right lung volume.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

thorax

Slice width

0.75 mm

Scan length

348 mm

Reconstruction increment

0.5 mm

Scan direction

cranio-caudal

Reconstruction kernel

B40

Scan time

8.2 s

Slice collimation

0.6 mm

Tube voltage

120 kV

Pitch

0.8

Tube current

160 qual. ref. eff. mAs

Rotation time

0.33 s

CTDIvol

11.5 mGy

Postprocessing

syngo InSpace Lung Parenchyma Analysis

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Clinical Results Neurology

Case 7 Acute Left Hemispheric Ischemic Stroke: Comprehensive Stroke Imaging Using Neuro Volume Perfusion CT By Ramona Finzel and Peter Schramm, MD Department of Neuroradiology, University of Göttingen, Göttingen, Germany

HISTORY A 75-year-old female patient with history of arterial hypertension, diabetes mellitus and absolute arrhythmia was admitted to the neurological clinic with symptoms of acute stroke. Two hours prior, the patient had developed an acute, right-sided hemiplegia and a right-sided facial palsy. On physical examination the patient was global aphasic, showed a left-sided eye and head deviation and recurrent emesis (NIHSS 26).*

Furthermore, a significant prolongation of the mean transit time (MTT, Fig. 2C) and the time to peak (TTP) in both the complete MCA and ACA territories were found. On CT-Angiography (CTA), occlusion of the main stems of the left MCA (Fig. 3) and ACA were detected. Due to the presence of a large penumbra volume, it was decided to perform

DIAGNOSIS

EXAMINATION PROTOCOL

On initial non-enhanced cranial CT (NECT), intracranial hemorrhage and tumor were ruled out. A hyperdense media sign on the left side was visible as an early sign of ischemic stroke (Fig.1A). However, grey and white brain matter appeared normal (Fig. 1B). Volume perfusion CT (VPCT) indicated large areas of restricted brain perfusion in the left hemisphere. A substantial reduction of values of cerebral blood flow (CBF, Fig. 2A) as well as reduction of cerebral blood volume (CBV, Fig. 2B) were detected in the anterior and middle parts of the left middle cerebral artery (MCA) territory and in parts of the left anterior cerebral artery (ACA) territory.

intra-arterial thrombolysis and to start a bridging therapy with 20 mg rt-PA immediately. Unfortunately, both thrombolysis therapies were unsuccessful (Fig. 4). Two days later, the follow-up NECT showed the delineation of complete territory infarctions of the MCA and ACA, brain edema and severe midline herniation (Fig. 5).

SOMATOM Definition AS+

SOMATOM Definition AS+

CT -Perfusion

CTA Vessel analysis

Scan area

head

head

Scan length

96 mm (VPCT)

300 mm

Scan direction

cranio-caudal

cranio-caudal

Scan time

40 s, one scan every 1.5 s

2.91 s

Tube voltage

80 kV

120 kV

Tube current

200 Eff. mAs

120 Eff. mAs

Scan mode

Adaptive 4D Spiral

Spiral

eff. dose

5.2 mSv

3.1 mSv

Rotation time

0.3 s

0.3 s

Slice collimation

0.6 mm

0.6 mm

Slice width/Increment

5 mm/3 mm

1.5 mm/1 mm

Reconstruction kernel

H20f

H20f

Scanner

Contrast Volume/Flow rate

35 ml Iomeprol 350 @ 5 ml/s

40 ml Iomeprol 350@ 5 ml/s

20 ml NaCl @ 5 ml/s

25 ml Iomeprol 350@ 2,5 ml/s 20 NaCl @ 2,5 ml

Start delay *NIHSS 26 (National Institute of Health Stroke SCORE 26).

Postprocessing

4s

4s

syngo Volume Perfusion CT –

Bolus tracking

Neuro (VPCT-Neuro)

syngo Neuro DSA

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1A

2A

2B

1B

2C

2D

1 A hyperdense media sign on the left side was visible as an early sign of ischemic stroke (Fig.1A, arrow). However, the differentiation of grey and white brain matter appeared normal (Fig. 1B).

2 Volume perfusion CT (VPCT) indicated substantial reduction of values of cerebral blood flow (CBF, Fig. 2A) as well as reduction of cerebral blood volume (CBV, Fig. 2B) were detected in the anterior and middle parts of the left MCA territory and in parts of the left ACA territory. Furthermore, a significant prolongation of the mean transit time (MTT Fig. 2C) could be observed. A large penumbra could be detected (yellow) in regards to a smaller core infarct (red, Fig. 2D). Therefore intra-arterial lysis was indicated.

3

3 Due to complete stroke assessement the CTA revealed an occlusion of the main stem of the left MCA.

4

5

4 Intraarterial thrombolyses failed to open left MCA.

5 Follow-up NECT showed the delineation of complete territory infarctions of the MCA and ACA, brain edema and severe midline herniation.

detector width, even smallest areas of hypo-perfusion can now be analyzed throughout the whole brain with VPCT. Therefore, the advent of VPCT renders important information about the com-

plete volume of tissue at risk of infarction and should be implemented in a comprehensive stroke CT protocol.

COMMENTS With VPCT, analysis of the brain perfusion parameters of the whole brain is possible. Contrary to standard perfusion CT, which allows analysis only of restricted areas of the brain depending on the

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Clinical Results Neurology

Case 8 SOMATOM Definition AS+: Neuro Volume Perfusion CT of Intracerebral Metastatic Disease By Ramona Finzel and Peter Schramm, MD Department of Neuroradiology, University of Göttingen, Göttingen, Germany

HISTORY A 69-year-old female patient with a history of bronchial carcinoma presented to the Department of Neurology with a discrete left-sided, arm-accented, hemiparesis since the evening. She was fully orientated but very cachectic and in poor general condition.

DIAGNOSIS Neuroradiologic examination consisted of a cranial, non-enhanced CT (NECT) scan followed by Volume Perfusion CT (VPCT). NECT revealed a tumor in the subcortical white matter of the right parietal lobe (Fig. 1A). The tumor showed a rim-like hyperdensity with a central loss of density on NECT and was surrounded by an edema. A second small cortical lesion was visible in the right anterior lobe (Fig. 1B).

1A

Assuming that the patient was suffering from multiple metastasis, we performed VPCT. The calculated permeability maps of VPCT showed multiple lesions with disrupted blood-brain-barrier throughout the whole brain (Figs. 2A–F), indicating the presence of numerous brain metastasis. The lesions showed an elevation of cerebal blood volume (CBV, Fig. 3) and contrast enhancement on the MIP images. In addition, we detected a severe prolongation of the mean transit time (MTT, Figs. 4A-C) and time to peak (TTP) in parts of the right MCA territory. The follow-up MRI examination on the same day visualized various metastasis supra- and infratentorial. In addition, we found subacute ischemic lesions on diffusion-weighted images in the area supplied by the right MCA which were al-

1B

ready indicated by the prolongated MTT and TTP on VPCT.

COMMENTS This case illustrates that VPCT can depict disturbances of the blood-brain-barrier even within smallest lesions that are not visible on NECT. Therefore VPCT is a meaningful method to reveal smallest metastasis within the scope of a CT examination. Further, this example demonstrates the multi-modality of VPCT. Although the examination and the postprocessing were focussed on the assumed diagnosis “tumor”, we were able to uncover the supplemental ischemic lesion on the parameter maps.

1 NECT revealed a tumor in the subcortical white matter of the right parietal lobe (Fig. 1A, arrow). The tumor showed a rimlike hyperdensity with a central loss of density surrounded by an edema. A second small cortical lesion was identified in the right anterior lobe (Fig. 1B, arrow).

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2A

2B

2C

2D

2E

2F

2 VPCT showed multiple lesions with disrupted blood-brain-barrier throughout the whole brain (Figs. 2A–F, arrows), indicating the presence of numerous brain metastasis.

3

4A

3 Additionally VPCT showed an elevation of cerebal blood volume (CBV) of the tumor.

4B

4C

4 3D evaluation of the brain detected an infarct seen as severe prolongation of the mean transit time (MTT) in parts of the right MCA territory.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition AS+

Scan area

head

Spatial resolution

0.33 mm

Scan length

96 mm (VPCT)

Slice width/Increment

5 mm & 3.0 mm increment

Scan time

40 s, one scan every 1.5 s

Reconstruction kernel

H20f

(27 scans)

Contrast

Scan direction

cranio-caudal

Volume/Flowrate

Tube voltage

80kV

Tube current

Eff. 200 mAs

Start delay

4s

Scan mode

Adaptive 4D Spiral

Postprocessing

syngo Volume Perfusion CT –

eff. dose

5.2 mSv

Rotation time

0.3 s

35 ml Iomeprol 350 @ 5 ml/s 20 ml NaCI @ 5 ml/s

Neuro (VPCT-Neuro)

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Clinical Results Neurology

Case 9 Dual Source CT: Visualization of Brain Vessel Connection of Siamese Twins By Anirudh Kohli, MD, Head Department of Radiology, Breach Candy Hospital Trust, Mumbai, India

1A

1B

1A Overview with volume rendering technique (VRT) showing the connection of both skulls.

1B Blood-flow through the connected head-vessel system of the conjuncted twins, demonstrated by VRT during administering contrast medium into the artery system of twin one (left person). Venous drainage can be found in the brain of twin two (right person).

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Neurology Clinical Results

HISTORY Two children, 3½-year-old female twins, fused at the cranium since birth (craniophagus), were transferred to the department of radiology for prearrangement of separation. For the pre-operative diagnosis and surgery planning, a CT-Angiography was performed to evaluate the vascular communications between the connected brain tissues of both children. The dissection of these communications was the key challenge for the separation procedure. In preparation for the CT scan and for brain vessel visualization, twin one was injected before twin two and finally, both were injected simultaneously.

2A

2 MIP visualization of vesselconnection: inflow of contrast media into the arteries of twin one (left) with drainage via the venous vessel system of twin two (right, Fig. 2A) and vice versa in a second CTscan afterwards (Fig. 2B).

2B

DIAGNOSIS The CT imaging revealed both venous communications as well as arterial connections. The arterial communications were well visualized in the superficial cranial branches of the external carotid. The superficial temporal and frontal artery of twin one and the superficial temporal and occipital artery of twin two were found to be communicating. This brain vessel anomaly was recognized to be the reason for volume overload in the brain tissue of twin two, thus resulting in hypertensity.

COMMENTS The results of the CT imaging provided excellent orientation for the surgical team to prepare a safe separation of the twins. A CT-Angiography was preferred over an MR-Angiography due to the very short scan time required. This allowed a short sedation time, lowering the sedation risks for the children while concurrently delivering excellent image quality. With Dual Energy CT-Angiography, small vascular communications could be visualized that are critical in a pre-operational workup. This information is important to know exactly – before starting a surgery of this difficulty and severity.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

head

Scan length

500 mm

Scan time

16 s

Scan direction

cranio-caudal

Tube voltage A/B

140/80 kV

Tube current A/B

70/297 quality ref. mAs

Rotation time

0.5 s

Spatial resolution

0.33 mm

Slice collimation

0.6 mm

Slice width

0.6 mm

Kernel

H10f

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Clinical Results Neurology

Case 10 A Rare Anomaly of the Middle Cerebral Artery Detected by Three-Dimensional Subtraction CT-Angiography Jacqui Fielding Department of Radiology, Angliss Hospital, Upper Ferntree Gully, Melbourne VIC, Australia

HISTORY

COMMENTS

A 66-year-old woman with a history of hypertension and recent headaches presented at the hospital with an acute onset of vertigo, fatigue and severe headache. On examination and questioning of the patient, it was found that her mother died at an early age from complications of a cerebral aneurysm. The patient was referred for a brain CT and brain CTA to rule out sub-arachnoid hemorrhage and aneurysm.

In this 66-year-old woman, preoperative angiography and 3-dimensional computed tomography angiography revealed a double aneurysm at the right middle cerebral artery (Circle of Willis).

DIAGNOSIS The non-enhanced brain CT shows no sign of subarachnoid bleeding. Using the functionality of digital subtraction CT-Angiography, automatically subtracting a non-contrast from a contrast enhanced study, the complete cerebrovascular tree could be demonstrated and two progressed aneurysms in the middle cerebral arteries could be detected.

*Duplication of the middle cerebral artery.

Both aneurysms were clipped and superficial temporal artery-DMCA* anastomosis was performed. She was discharged with no neurologic deficits.

EXAMINATION PROTOCOL Scanner

SOMATOM Emotion 16

Scan area

Circle of Willis

Scan length

80 mm

Scan direction

caudo-cranial

Scan time

7s

Tube voltage

100 kV

Tube current

100 Eff. mAs

Dose modulation

CARE Dose off

CTDIvol

15 mGy

Rotation time

0.6 s

Pitch

0.8

Slice collimation

16 x 0.6 mm

Slice width

0.75 mm

Reconstruction increment

0.5 mm

Reconstruction kernel

H31

Contrast

Ultravist 370

Volume

50 ml

Flow rate

4 ml/s

Iodine delivery rate

4 ml/s

Start delay

CARE Bolus

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Neurology Clinical Results

1

2

1 View into the brain via Volume Rendering Technique (VRT), showing the position of the double aneurysm in the Circle of Willis.

3A

2 Detailed VRT image, showing both aneurysms, located consecutively in an aortic brain vessel.

3B

3 View on the two aneurysms in the Circle of Willis, virtually separated from brain tissue in VRT (Fig. 3A) and in comparison in MIP (Fig. 3B).

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Clinical Results Acute Care

Case 11 Complete Thorax with Flash Spiral By Martine Remy-Jardin, MD, PhD and Jacques Remy, MD University Center of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille, France

HISTORY

COMMENTS

A 64-year-old male patient was referred to the department of radiology for evaluation of abnormal chest radiographic findings in March 2006. This patient was an ex-smoker (smoking cessation 18 years ago) with a cigarette consumption of 20 pack-years. At the time of first referral, chest CT revealed the presence of a spiculated nodule in the right middle lobe. This was associated with hilar and mediastinal adenopathies with a final diagnosis, in June 2006, of right middle lobe adenocarcinoma with lymph node metastases. This diagnosis, obtained after atypical resection of the right middle lobe nodule and lymph node sampling, indicated chemotherapy followed by radiotherapy at the level of the tumoral zones. In 2008, this patient was also diagnosed with bone and cerebral metastases.

This examination was obtained with an ultra fast Flash Spiral mode which made the overall examination very comfortable for this patient in poor general condition. The optimization of data acquisition and administration of contrast medium generates high quality images of the mediastinum that are devoid of respiratory motion artifacts. This kind of

acquisition makes the analysis of the coronary arteries at the same time possible. In this case, the patient’s heart rate was 65 bpm. The delineation of aortic and pulmonary valves was excellent. The only limitation was the presence of interpolation artifacts around the ribs, noticeable on lung images.

1

DIAGNOSIS The present CT examination was indicated for the follow-up of the chest lesions in a patient in poor general condition. This examination showed sequellae of right middle lobe resection and areas of airspace consolidation in the lung parenchyma located close to the right hilum, caused by radiotherapy. Furthermore multiple areas of non-specific ground glass attenuation in both lung lobes were discovered, predominantly on the right side, resulting from radio therapy or an infection. In addition to hilar and subcarinal adenopathies, osteolytic lesions of the thoracic spine and the sternum were found.

1 Even without ECG-triggering, sharp delineation of aortic valve leaflets is possible.

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Acute Care Clinical Results

EXAMINATION PROTOCOL Scanner

Flash Spiral mode

Scan area

whole chest

Reconstruction increment

1 mm

Scan length

345 mm

Reconstruction kernel

BB20f (mediastinum); B50f (lung)

Scan direction

cranio-caudal

Contrast

350 mg of iodine/mL

Tube voltage

120 kV

Tube current

52 Eff. mAs

Volume

80 ml

Heart rate

65 bpm

Flow rate

4 ml/s

Pitch

3.2

Start delay

18 s (ROI within descending aorta)

Spatial resolution

0.33 mm

Postprocessing

syngo InSpace

Slice width

1 mm

2

3

2 Coverage of the entire lung in ultra-short breath hold time of < 3 sec. Note the apparent right lower lobe consolidation secondary to lung resection.

3 Sagittal view of the right lung highlights the high quality of lung images from top to bottom of the volume scanned.

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Clinical Results Acute Care

Case 12 Dual Source CT: Carotid Stenosis Diagnosed with Dual Energy By Eva Hendrich, MD and Stefan Martinoff, MD Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

HISTORY

DIAGNOSIS

COMMENTS

A 65-year-old woman presented with complaints about recurring dizziness. Weeks previously, she has been stented in the right carotis interna. During a routinely conducted ultrasound examination, a stenosis was discovered in the left arteria carotis interna. To confirm this result and for a correct planning of stent positioning and PTA (percutanuous transluminal angioplasty), a CT examination with Dual Energy technology was subsequently performed.

With CTA (CT-Angiography), indicated by the ultrasound survey, a quite severe stenosis in the branch of the left arteria carotis interna with cranio-caudal extension of 13 mm could be confirmed. Furthermore, the CTA delivered additional information that an expanded semi-circular atheromatous plaque was the cause for the stenosis. In the area surrounding the implanted stent, in the proximal right arteria carotis interna, a stenosis could be ruled out. Moreover other profound arteriosclerotic alterations in the region of the basal brain arteries could also be ruled out by the CTA survey.

syngo Dual Energy Bone Removal delivers credible information about vessel status. Therefore, the non-overlapping imaging of the vessels plays an important role, as well as the option of hardplaque visualization that affords a detailed conclusion about vessel lumen and plaque. A very positive effect is the uncomplicated integration of Dual Energy into the post processing procedure. Hence syngo Dual Energy Bone Removal has become an inherent part of our vascular workflow.

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

carotis

Rotation time

Scan length

281 mm

Spatial resolution

0.33 mm

Scan time

6s

Slice collimation

0.6

Scan direction

cranio-caudal

Reconstructed slice thickness

0.75 mm

Tube voltage A/B

140/80 kV

Increment

0.6

Tube current A/B

204/48 Eff. mAs

Kernel

D30f

0.33 s

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Acute Care Clinical Results

1A

1B

1 VRT Visualization of syngo Dual Energy scan shows earlier PTA result in right carotid artery (Fig. 1A). Inverted Maximum Intensity Projection (MIP) of the same scan (DE) (Fig. 1B).

2A

2B

2 syngo InSpace advanced vessel analysis (InSpace AVA) measured accurately the grade of the stenosis for use of later PTA (Fig. 2A). syngo Hard Plaque unveiled the calcified plaque (red) versus remaining lumen of the carotid arteries (blue) (Fig. 2B).

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Clinical Results Orthopedics

Case 13 Screw Placement and Pelvic Osteoplastie Under CT – Fluoroscopic Guidance By Ralf-Thorsten Hoffmann, MD*, Bianca Beyer, MD**, Tobias F. Jakobs*, Maximilian F. Reiser, MD* *

Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany Department of Surgery, University of Munich, Campus Großhadern, Munich, Germany

**

HISTORY A 68-year-old male patient with a history of renal cell carcinoma 4 years prior, presented in the department of radiology. Due to pelvic pain occurring during his follow-up, a MSCT of the pelvis was obtained.

DIAGNOSIS The examination showed a large osteolysis in the sacrum and the adjacent iliac bone (Fig. 1). Furthermore, a pathological fracture was detected as stigmata of the recurring tumor. After an inter-disciplinary case discussion, the decision was made to treat the patient with a combination of angiographic embolization of the strongly vascularized tumor, followed by CT guided placement of two screws supported by

a CT guided osteoplasty during the same treatment session.

COMMENTS After placing the patient in a stable lateral position with the help of a vacuum bed, a CT scan was performed using the i-Spiral mode. The correct positioning of the screws was planned on axial images. Furthermore, path planning and calculation of the screw length was performed on the automatically obtained 3D images using the needle oriented view. The following procedure was monitored by repeated control with i-Fluoro mode. By using Hand CARE mode, K-wires were positioned through small skin incisions by the interventional radiologist under CT fluoroscopic guid-

ance using the i-Fluoro mode (Fig. 2). The screws were placed via K-wires by the surgeon in order to avoid a too deep insertion of the screw head into the weakened bone (Figs. 3A-B). A major support for these control scans is the One Click Table Position, bringing the patient back to the exact same position, avoiding additional fluoroscopic CT examination. Procedure times and radiation exposures are thereby significantly reduced. After the insertion of two screws, (Fig. 4) the next step was the insertion and positioning of two vertebroplasty canulas into the osteolysis and application of the PMMA cement under CT fluoroscopic guidance by the radiologist using the needle artefact reduction tool i-Needle Sharp (Figs. 5A-B).

EXAMINATION PROTOCOL Scanner

SOMATOM Definition

Scan area

pelvis

Rotation time

0.5 s

Scan length

4.8 mm

Slice collimation

12 x 1.2 mm

Scan time

i-Fluoro

Slice width

4.8 mm B50s

Tube voltage

120 kV

Reconstruction kernel

Tube current

25 Eff. mAs

Postprocessing

CTDI vol

289 mGy

Intervention Pro Adaptive 3D Intervention

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1

2

1 The CT examination showed a large osteolysis in the sacrum and the adjacent iliac bone.

2 K-wires were positioned under CT fluoroscopic guidance using the i-Fluoro mode.

3A

3B

3 The screws were placed via K-wires in order to avoid a too deep insertion of the screw head into the weakened bone.

4 4 Two screws were inserted into the broken pelvic bone.

5A

5B

5 Two vertebroplasty canulas were inserted and positioned into the osteolysis (Fig. 5A) and PMMA cement was supplied under CT fluoroscopic guidance using i-Needle Sharp (Fig. 5B).

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Science

CT-Guided Osteosynthesis in Instable Pelvic Fractures By Tobias F. Jakobs, MD*, Ralf-Thorsten Hoffmann, MD*, Thomas Löffler, MD** *Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany **Department of Surgery, University of Munich, Campus Großhadern, Munich, Germany

Recent improvements in mortality due to high-energy trauma can be attributed to the progress made in modern critical care medicine including early fracture stabilization. Most of the complications of classical stabilization techniques are related to the surgical exposure itself, rather than to the initial injury. It therefore seems reasonable to consider less invasive

treatment options. The most frequent percutaneous application is the transiliosacral screw fixation using only fluoroscopy guidance. Given the anatomical complexity of the pelvic structures, this surgical procedure remains a challenging task. An 18-year-old woman was presented at the CT unit for a whole-body scan after having experienced a severe car acci-

1A

dent. The CT scan revealed – beside a right sided lung contusion – an instable fracture of the pelvic bone involving the superior ramus of the pubic bone and the wing of the sacral bone on the left side (Figs. 2A-B). On day 5 after the trauma the patient was referred to the interventional radiology unit for CT-guided osteosynthesis.

1B

1C

1 CT-guided osteosynthesis in instable pelvic fractures

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Science

Procedure The procedure was performed under general anaesthesia in cooperation with trauma surgeons (Figs. 1A-C). The patient was placed in a strict lateral position using a vacuum mattress with the fractured pelvis pointing to the 2A

top. A planning CT was performed to identify the most appropriate position for the screw. Using a Siemens SOMATOM Definition AS+ CT scanner and the new Siemens Interventional Suite for 3D-guided interventions, planning procedures have been dramatically 2B

2 CT scan revealed an instable fracture of the pelvic bone involving the superior ramus of the pubic bone and the wing of the sacral bone on the left side (Fig. 2A). VRT supports surgical planning planning (Fig. 2B).

3

3 With the 3D approach, the placement of the screw into the target area can be perfectly monitored using a guide wire.

improved. Additionally, a 78 cm large bore allows convenient work within the gantry. The innovative table-side control module “i-Control” enables operating all table and scanner movements from inside the scan room (Fig. 1B, arrow), improving the workflow as well on such complex procedures. For this patient, the correct positioning of the screw was planned on axial images. Furthermore, path planning and calculation of the screw length were performed on the automatically obtained 3D images using the needle oriented views. A combination of CT Fluoroscopy with the new iFluoroscopy mode and a sequential approach with 3D i-Sequence mode was used to securely drive a wire through the iliac bone and the sacral wing into the first sacral vertebral body. Especially the 3D i-Sequence mode with instant display of the wire in an axial, coronal and sagittal view (MPR) permitted excellent visualization and increased the interventional radiologist’s confidence not to harm, e.g. the neuro-foramen, or to protrude outside the first sacral vertebral body. This enables a safe placement of the screw even in complex anatomy (Fig. 3). With the guide wire in place, the screw could be advanced into the target area to provide compression on the fractured sacral wing (Fig. 3). Then, the guide wire was withdrawn. Before the patient was removed from the CT-table, a control scan was conducted and MPR as well as VRT were reconstructed (Fig. 4).

Comments 4

4 Using CT guided interventions, the screw can be placed in the target area without providing compression of the fractured sacral wing.

With the availability of the new 3D-guided Interventional Suite, we have chosen the approach of CT-guided osteosynthesis. In comparison to classic surgical techniques of internal fixation, the new interventional procedure brings advantages for both patients and the hospital. Less complications, due to less extensive soft tissue damage associated with long bed rest, reduce the likelihood for pneumonia, deep vein thrombosis etc., facilitate a faster recovery of the patient and finally an earlier discharge.

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Science

Clinical Advantages of Automated CT Tumor Measurement Lesion measurement has long been an inexact science. Yet, judging the patient’s disease regression or progression is, to a large extent, based on documentation of exact changes in tumor size. Currently, when tumor masses are encountered in daily clinical practice, manual measurements made with electronic calipers are utilized. These are quite time consuming and not reliably exact from examination to examination. By Alec J. Megibow, MD, MPH, FACR New York University Medical School, New York, USA

Because tumors are complex shapes, the axis of measurement chosen over serial time points may vary. RECIST (Response Evaluation Criteria in Solid Tumors) has been widely adopted in the U.S. and WHO (World Health Organization) criteria elsewhere as the standard reporting parameters for lesion size. Among many problems with these methods, constraining measurements into the axial plane may under- or overestimate the longest diameter of the lesion. If software could be developed to segment the 3D volume from an MDCT data set, the truest approximation of the maximal diameter (RECIST diameter) could be determined. Additionally, such software should be able to “store” this information so that the same exact lesion could be followed over the course of the patient’s treatment, thereby eliminating variances in manual measurement. Finally, converting these observations onto a spreadsheet would aid institutional compliance in clinical trial, with benefits not only to improved patient care, but also increased opportuni-

1

1 All segmentation and measurement results are stored and reported. The list includes the most important lesion information, such as WHO and RECIST diameters, Volumes and their changes since the last examination. A comprehensive report, including key images, can be generated and stored.

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Science

ty for ongoing funding, since it improves the institution’s ability to record data in a usable format. Siemens syngo CT Oncology is a clinically available suite of tools that provides all these capabilities (Fig. 1).

2A

2B

3A

3B

Algorithm Refinement In preliminary testing of the syngo CT Oncology algorithm, 27 hepatic metastases in 13 patients were evaluated using prototype software that defined the edges, maximal and orthogonal diameters of the targeted lesion. The autosegmented measurements were compared to manual measurements made by electronic calipers, and the difference between the two was recorded. As a prototype, this algorithm performed well: Using 4 mm slices, long diameters of 67 percent of metastases of less than 5 mm were correctly measured within 2 mm of the manual measurement. With this information, the algorithm was further refined. In our next evaluation of the actual, clinical application, it performed exceptionally well. Eighty-seven hepatic masses from 33 patient studies were evaluated. Here, we sought to compare the tool’s ability to obtain RECIST diameters of hepatic metastases against manual evaluation of the same lesion. There was a high degree of concordance between RECIST diameters obtained using automated segmentation versus manual measuring. In fact, 74 percent of lesions differed by less than 5 mm. A finding of particular importance: the syngo CT Oncology segmentation algorithm is independent of absolute HU measurements. Thus, there is no dependence on the quality of the contrast injection, which makes the tool particularly valuable for serial observations of lesions in patients where it is difficult to obtain a good injection (such as those undergoing chemotherapy).

Comprehensive Evaluation and Reporting With syngo CT Oncology, the lesion is presented in axial, coronal and sagittal displays with RECIST and WHO measure-

2 3 Example of a 73 year old female patient with known carcinoid on treatment. Follow up is performed in a 3 month interval (Figs. 3A-B). The datasets are automatically registered and displayed synchronously for easy follow-up comparison. The lesion is then identified in both studies and is automatically segmented and evaluated. Sagittal and 3D reformats are shown (Figs. 2A-B – base exam, Figs. 3A-B – 3 month follow up).

ments, and volume. The radiologist can decide whether to accept the results or edit, if necessary. Evaluation results are comprehensively presented and the images stored to PACS, ensuring that any follow-up measurements are conducted with a consistent approach to the correct lesion(s). This is particularly helpful in following tumor progress.

Future Directions RECIST and WHO criteria do not currently include volume; it is the next, expected step in comprehensive tumor measurement. It is theorized that volume may be more sensitive to tumor growth than diameter because lesion diameter can re-

main consistent while volume changes. Clearly, the ability to measure volume is an asset, even if it has not yet been clinically validated. We are currently in the process of comparing changes in volume against diameter changes as measured with RECIST criteria. With its ability to record and evaluate all tumor parameters, syngo CT Oncology is an advantageous tool for the radiologist. This software helps solidify the role of the radiologist as someone who goes beyond simple diagnosis, but rather, a physician who, through the use of a wide variety of image processing tools, can provide information that directly impacts therapeutic decisions.

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CT put to the Test CT units from various manufacturers were recently put through practical tests at the German Heart Center in Munich in order to determine radiation exposure levels for patients during everyday operations. The results indicate that applied doses depend not only on the specific device, but are also significantly influenced by the operator. The study further shows that Siemens has developed particularly efficient radiation-saving equipment. By Tim Schröder

Computed Tomography (CT) has established itself in the past few years as a non-invasive procedure for obtaining medical imagery. With every new product generation, manufacturers have paid considerable attention to reducing the levels of radiation to which patients are exposed. Never the less, the question of dose is becoming increasingly important as CT-technology becomes more widespread. Not only the technical data provided by manufacturers is of interest, but especially the actual radiation doses to which patients are exposed during treatment. To this end, the German Heart Center in Munich, in cooperation with the American Mayo Clinics in Rochester and Jacksonville, and the Friedrich-Alexander University in Erlangen-Nuremberg,

“It’s clear to see that Siemens has quite evidently developed a very radiation-saving system.” Jörg Hausleiter, MD, Cardiologist, associated Professor of Medicine, German Heart Center Munich, Germany

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1A

Germany, conducted an International Prospective Multicenter Study on Radiation Dose Estimates of Cardiac CTAngiography in Daily Practice (PROTECTION-I). The study compared five CT units from four different manufacturers. The basis of the study was 1,965 cardiac CT scans that were carried out in a total of 50 clinics and heart centers. The study showed clear differences in radiation doses depending upon both the CT system manufacturer and the behavior of the operator. The study especially underlines that radiation can be significantly reduced by more consistently using already existing technologies for dose reduction in CT systems. “Until now the only information available for evaluating individual devices has been to use systematic phantom measurements or physical readings provided by the manufacturers,” said Jörg Hausleiter, cardiologist and associate professor of medicine, German Heart Center in Munich. “Conversely, the new study delivers, for the first time, data obtained from individual patients, including abundant patient data such as size and weight.” As was shown, the radiation dose varies considerably, by as much as a factor of six. Hausleiter: “An emphasis of our work was to test the effectiveness of the different software tools for reducing radiation.” This included the so-called “ Automatic Exposure Control,” which automatically adjusts the CT radiation intensity to the anatomy of the patient. Generally more radiation must be used when conducting tests of larger bodies. The Automatic Exposure Control is already well established for noncardiac scanning, but it was not specifically developed for cardiac CTs. All of the devices tested were equipped with it. “ECG-Pulsing” is also implemented in all devices. This synchronizes CT radiation to the ECG, so that the image is recorded during the late diastolic phase, when the heart is not moving. It is only at this time that the apparatus increases the radiation intensity to the necessary high level. During the in-between phases, X-ray emission is kept to a minimum. Additionally, Hausleiter’s team researched the influence of the 100 kV Scan Protocol.

1B

1 49-year-old patient, former smoker with high cholesterol, who repeatedly developed symptoms of dyspnea in combination with a difficult to adjust hypertension. SOMATOM Definition with Adaptive Cardio Sequence revealed with a quick 1.8 mSv low dose cardiac examination a high grade lesion in the right coronary artery. The patient was transferred from CT directly to the cath lab for a percutaneous intervention.

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This protocol is not integrated by all manufacturers, but is available, for example, with the Siemens systems. Until now, it was unclear as to how much of a reduction of dose came with the 100 kV technology in comparison to the conventional 120 kV protocol. As a further tool, the researchers evaluated the so-called, stepand-shoot method. In contrast to SpiralScan, this procedure does not expose the entire heart area to radiation through the entire test. Once again, thanks to synchronization with the ECG, exposure is limited to the diastolic phase. Then the CT device moves the patient forward so that the next heart segment can be examined. At the time the study was enrolling patients, this low dose scan mode was only available in a preliminary research version at selected Dual Source Computed Tomograph (DSCT) SOMATOM Definition sites. Thus, this mode had been used infrequently on DSCT systems in PROTECTION I and patients could not benefit from the tremendous dose saving potential of the system at that time. However, shortly after the publication of the study, the Siemens proprietary step-and-shoot mode, “Adaptive Cardio Sequence,” and the software upgrade syngo 2008G has become available for all DSCT customers.

100 kV Tube Reduces Dose by Half Hausleiter primarily noted during the analysis of the data how often the individual software solutions were implemented. It became evident that the established Automatic Exposure Control was employed in more than a third of all cases, but, ultimately, hardly contributed at all to dose reduction. ECG-Pulsing was employed in 78.7 percent of the cases and reduced the dose by about 20 percent. This is minor though, in comparison to the effect of the 100 kV tube that reduced dose by half – while providing the same image quality in adequately selected, non-obese patients. However, this technology has so far been used in only 5.8 percent of all cases. “When testing patients, physicians want to be secure and are afraid that by using the 100 kV mode the image quality will be inadequate for

confident findings,” said Haus-leiter. The situation is similar with the step-andshoot technology. In comparison to the spiral-scan, this method reduces the dose by 68 percent, but so far has only been used in 6.2 percent of all cases. According to Hausleiter, the multivariate analysis of the PROTECTION-I study does not permit a direct comparison of devices, since operator behavior has an influence. However, the Siemens 64-slice scanner was associated with the lowest radiation dose in cardiac CT-Angiography and served as the reference value for assessing the other systems. Close behind, in third place, was the DSCT SOMATOM Definition. Despite this, in comparable clinical situations in the study, the average radiation dose of the DSCT SOMATOM Definition was considerably lower than that of the competing scanners ranked in fourth and fifth place. “It’s clear to see that Siemens has quite evidently developed a very radiation-saving system,” said Hausleiter. The multivariate data additionally allows another interpretation: satisfactory dose values were only attained in the PROTECTION-I study when the radiation reduction software was frequently employed. “Based on the available results we can conclude that Siemens evidently belongs to those manufacturers, that provide especially good systems training for their customers, so that operators can take advantage of the total radiation reduction potential of the device.”

Dual Source-Scanner Unique Worldwide Thomas Flohr, head developer of the SOMATOM Definition Dual Source CT at Siemens Healthcare in Forchheim, Germany, believes that, “the DSCT would have performed even better if it had already been equipped with current, improved version of the step-and-shoot technology during the study.” At any rate, the Dual Source scanner is worldwide the only CT equipped with two X-ray tubes and two detectors, that are connected to one another at an angle of 90 degrees. This means that the heart is simultaneously scanned from two different angles. With a gantry rotation speed of only 0.33 seconds, one achieves a temporal resolu-

tion of 83 milliseconds – so quick that sharp images are possible from even rapidly beating hearts. Despite having two X-ray sources, the total dose is less than that of conventional single source devices, thanks to the extremely short exposure time. “In discussions about radiation reductions, one should not get carried away,” said Hausleiter. “To date, the level of radiation of cardiac CT-Angiography is very comparable with other diagnostic CT studies, such as multiphase abdominal and pelvic CTs, which we perform in daily routine without worrying so much about radiation exposure.” Naturally, Hausleiter knows that, despite this, caution is required, especially when testing children and youths. “To this extent, it makes sense that manufacturers continue to reduce the dose. Though particularly in applications such as cardiac CT, the advantages of the method and the superior image quality weighs much more positively than any possible radiation risks.”

Immense Potential Hausleiter is currently advancing the follow-up studies, PROTECTION-II and PROTECTION-III. PROTECTION-II systematically compares the image quality when using 100 and 120 kV tubes. PROTECTION-III studies the influence of step-andshoot technology in the same way. At the end, Hausleiter wants to provide physicians with clear suggestions, with which the technologies can be used without any loss of image quality – up to approximate body volumes or weights. The goal is clear: In the future, radiologists and cardiologists should be less hesitant to use the technologies. Hausleiter: “Nevertheless, the potential is immense. Until now with conventional CT technology the average radiation dose during a CT test was in the average 13 to 15 mSv. By consistently using dose reduction tools, today we can already achieve an average of less than 3 mSv.” Tim Schröder is a biologist and former editor of the science section of the Berliner Zeitung. He is now a freelance writer in Oldenburg, Germany, and publishes regularly in scientific journals such as the german edition of Scientific American, Max-Planck-research and Fraunhofer-Magazin.

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Siemens benchmarks in low dose Three of Siemens’ latest and most effective dose saving features – and with the SOMATOM Definition Flash the further development in dose reduction technology continuously proceeds (see Cover Story). MinDose: – 30% dose compared to conventional ECG-Spiral dose 1A

Tube Current

Advanced Pulsing with Dual Source CT

20%

4%

MinDose

1A Spiral Acquisition: MinDose reduces the tube current from 20% to 4% during the systolic phase of an RR interval to lower the dose to the patient leading to a dose reduction of about 30%. In combination with reduced tube current of 100 kV dose levels of 3.9 mSv can be achieved in routine clinical use.

Adaptive Dose Shield: – 25% dose for spiral acquisition 1B

STRATON with Adaptive Dose Shield

No Pre-Spiral Dose

No Post-Spiral Dose

1B Adaptive Dose Shield: The SOMATOM Definition AS is the first commercially available CT-scanner that addresses the problem of over-radiation with a dynamic collimation technique reducing spiral overradiation up to 25% for a heart scan.

Adaptive Cardio Sequence: – 68% dose compared to conventional ECG-Spiral dose 2

Scan Table

Move

Scan

Table

React

Scan

Move

extra-systole

2 Conventional Step & Shoot is vulnerable for extrasystolic heart beats. Adaptive Cardio Sequence, with arrhythmia compensation enables the system to react on extra systoles. In clinical routine, dose levels of 1.2 – 2.6 mSv can be reliably achieved.

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Virtual Histology with Dual Source CT In Tübingen, Germany, the partnership between radiologists and cardiologists at the University Clinic at Schnarrenberg – aided by Siemens imaging technology – is making great strides in the identification of vulnerable plaques. By Hildegard Kaulen, PhD

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Histology based on Dual Source CT is a new development.

Every fourth heart attack comes completely unexpected and cannot be explained by classic risk factors such as hypertension, hyperlipidemia, smoking, diabetes mellitus or genetic factors. Usually, the cause is the rupture of a vulnerable plaque. The exact risk of some atherosclerotic plaques has, until now, been very unpredictable. A study with the Dual Source SOMATOM Definition CT, at the clinic of the University of Tübingen in Germany indicates that this situation could soon change. It’s not uncommon that a fruitful collaboration stands at the beginning of an interesting new development. At Schnarrenberg, a hill that offers an unobstruct-

ed view over the surrounding countryside, radiologists working with Prof. Claus D. Claussen, MD, and cardiologists working with Prof. Meinrad P. Gawaz, MD, came together to perform an illuminating study. The goal was to use computed tomography to more accurately determine the extent and composition of atherosclerotic plaques. For this purpose, two procedures were compared: virtual histology using intravascular ultrasound (IVUS), and virtual histology using Dual Source CT. IVUS histology has been the gold standard for characterizing atherosclerotic plaques for the past three years. Histology based on Dual Source CT is, in con-

trast, a new development. The assessment of plaque volume and composition rests upon Hounsfield Unit (HU)-based color mapping. With the comparison, the two responsible physicians, radiologist Harald Brodoefel, MD, and cardiologist Christof Burgstahler, MD, entered new territory and obtained some fascinating results. With plaque volume assessment, the methods delivered almost identical results. With the determination of plaque composition, there were discrepancies that have apparent causes. Visual assessment, which is typically in use, almost always resulted in an overestimation of the plaque burden and an underestimation of vascular lumen.

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Topic Science

“We can well determine plaque volumes using DSCT based virtual histology.” Prof. Claus D. Claussen, MD, University of Tübingen, Department of Radiology, Tübingen, Germany

Despite many advances in treatment, cardiovascular disease remains the number-one cause of death in western, industrialized nations. However, myocardial infarctions are often not the result of high levels of coronary stenosis, but rather stem from the rupture of a vulnerable plaque. Burgstahler says: “Stable lesions with high degrees of luminal constriction typically lead to exercise induced angina pectoris. Should the coronary vessel gradually be blocked, collateral vessels often arise, so that not every vascular blockage necessarily leads to an acute heart attack. In contrast, when a vulnerable plaque ruptures, it usually results in an acute vascular blockage, and thus in a heart attack. The patient may have been completely free of symptoms until this point. The identification of vulnerable plaques can therefore be an important parameter for risk stratification.” In order to estimate the threat of plaque rupture, one needs to know the plaque composition. The most dangerous are those with thin fibrous caps and large fatty cores, not the highly calcified plaques. Vascular calcification is simply a measure of the general vascular plaque burden. For a qualitative analysis, it is therefore necessary to be able to differentiate between fibrous tissue, lipids, calcification and necrotic tissues. This is where virtual histology comes into play. The team from Tübingen investigated whether Dual Source CT and the Plaque Analysis Program of the latest syngo Circulation Package represented a reasonable alternative. With IVUS histology, the discrimination between different tissue types is not based on the conventional grey-scale image, but rather on the spectrum analysis of radio frequency data. Every histological class is assigned a color; thus there is one each for fibrous, necrotic, fatty-fibrous, and calcified material. The classification was previously validated by comparison with autopsy material. The fact that Dual Source CT can be considered for virtual histology has to do with its high level of spatial and temporal resolution. In both disciplines, the SOMATOM Definition sets industry stan-

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SOMATOM Definition sets industry standards to visualize coronaries and plaque in the vessel wall.

dards with 83 ms temporal resolution to freeze any cardiac motion and 0.33 mm spatial resolution to visualize the coronaries and plaque in the vessel wall.” Since it records images within a tenth of a second, produces hardly any motion artifacts from partial-volume effects and has highly homogenous Hounsfield Units, it possesses the technical prerequisites for virtual histology. “Until now, intravascular ultrasound has been the gold standard for assessing vascular lumen, vascular wall and plaque burden,” says Brodoefel. “Coronary angiography only gives information about the degree of stenosis. As an invasive procedure, IVUS has clear disadvantages. Every invasive procedure brings with it the risk of complications, and in addition, it is labor and cost intensive. Moreover, it is not possible to bring the ultrasound probe into every coronary vessel; some are too small and others have too high a level of stenosis. With Dual Source CT, the entire vascular tree with lumen and walls is represented. One can consequently observe the entire plaque situation. Finally, CT offers the opportunity to perform a more wide-ranging analysis than does intravascular ultrasound.” For Dual Source CT-based virtual histology, Burgstahler and Brodoefel first

determined thresholds for the Hounsfield Unit based on IVUS data. For this, the doctors matched the determined color maps of some plaques with the spectrum analysis of the corresponding radio frequency data, and obtained the following thresholds: 10 to 69 HUs stand for the fatty compartment of an atherosclerotic plaque, 70 to 158 HUs for the fibrous compartment, 159 to 436 HUs for the vascular lumen, and 437+ for calcification. Additional plaques were subsequently analyzed using both procedures and the results compared. Burgstahler notes: “We found a good correlation with volumes. The sizes of plaques can thus be equally well determined with both Dual Source CT and intravascular ultrasound. With plaque composition, however, there was only limited correspondence. A possible reason is the lower spatial resolution in relation to IVUS. Calcification also presents a problem, since it respectively leads to excessive overexposure with CT and loss of ultrasound waves due to interference when using IVUS. Dual Energy mode possibly brings some advantages for determining the plaque composition. We have not yet evaluated this mode on the coronary vessels.” The SOMATOM Definition can be used in Dual Source and Dual Energy mode. With Dual Source

mode, both tubes run with the same energy level. Dual Energy mode allows better differentiation of tissues by subtracting two different energy levels, but results in reduced temporal resolution. Noteworthy with this study was the high level of reproducibility of results. “The high inter-observer variability is a big problem with visually evaluating and manually segmenting atherosclerotic plaques,” explains Brodoefel. “In contrast, a HU-based plaque analysis eliminates many investigator-dependent steps. In our work, high inter-observer variability could not only be achieved for plaque volume but also for plaque composition. It remains questionable, however, how robust the results for possible serial CT investigations of the same plaques will be. Here the always-different contrast of the vascular lumens presents us with great challenges.” Prof. Claussen also attributes great significance to the study. “We can well determine plaque volumes using Dual Source CT based virtual histology,” he says. “The reproducibility is also high. For plaque composition analysis, we need improvements. In order to use virtual histology for screening or follow up controls, longterm studies are necessary anyway. They must demonstrate that there actually is a correlation between plaque compositions, determined using CT, and the risk of heart attack. We also need studies that show whether a specific intervention – such as statin therapy – changes plaque composition and thus positively influences risk. Furthermore, the levels of radiation exposure are still too high for screening or regular follow-up controls.” The study appears in: Brodoefel H, Reimann A, Heuschmid M, Tsiflikas I, Kopp AF, Schroeder S, Claussen CD, Clouse ME, Burgstahler C. Characterization of coronary atherosclerosis by dual-source computed tomography and HU-based color mapping: a pilot study. Eur Radiol. 2008 Nov; 18(11):2466-74. Epub 2008 May 20.

Hildegard Kaulen, PhD, is a molecular biologist. Following positions at Rockefeller University in New York and Harvard Medical School in Boston, she has been writing as a freelance science journalist for prestigious newspapers and science magazines since the mid 1990s.

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A smooth workflow in CT is important for any hospital to realize optimized capacity utilization.

Proactive Service for and by Radiologists A system failure not only brings throughput to a stop but it’s, above all, a nightmare when interventions are in process. The Medical Director of the Diagnostic and Interventional Radiology Department at the Tübingen University Hospital, Germany, Professor Claus D. Claussen, MD and various team members speak about the challenges of radiology and why proactive services such as the Siemens Guardian Program support clinical workflow. By Katja Stöcker, Siemens Healthcare, Erlangen, Germany

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Anja Reimann, MD, resident assistant physician, describes the rare but always possible event of a system failure as nerve-wracking: If, for example, the computed tomograph (CT) should go down during aspiration of an abscess, it could be unpleasant for the patient who might at that very moment have the guide canula in his or her body. If the system can be restarted quickly, there is only a small shift in the schedule. However, in the event of a relatively long failure, the patient must be called in again and the intervention must be repeated. She discusses some findings with Professor Andreas Kopp, MD, senior physician. “A system failure would be difficult for us here in radiology also because we cannot use the time for other productive activities. Our colleagues on the wards, for example, could take the case history of another patient or discuss a surgical procedure,” says Professor Kopp. Today, purchasing decisions are no longer made solely on the basis of product features. System availability and service are other important criteria that help decide the competitiveness of supplying companies. “We are under massive pressure to deliver competent diagnoses to our colleagues in the hospital or to the referring physicians with ever-faster turnaround times,” says Medical Director, Professor Claussen, describing an essential challenge for radiology. To

realize optimized capacity utilization, appointments are scheduled tightly. A system failure would immediately disrupt the workflow in his department and would also have ramifications for the workflow of the University Hospital Tübingen (UKT – Universitätsklinikum Tübingen), as a whole. “Therefore, in the event of a malfunction, technical service must be prompt and competent,” continues Claussen. For the various Siemens systems, including the high-end, Dual Source CT scanner SOMATOM® Definition, and the SOMATOM Sensation 64 CT system in Professor Claussen’s department, Siemens supports the workflow with a broad pallet of proactive services. Virus Protection for example is a service that protects Siemens systems from viruses, worms and trojan horses. System-specific usage and capacity-utilization data can be called up through the service Utilization Management. “It is important to recognize errors as early as possible – not only after the system shuts down,” says Claussen. The Siemens Guardian ProgramTM efficiently provides this proactive service.

Prompt Remote Repair Saves Time Through the Siemens Remote Service (SRS) platform, the medical device reports deviations of important system parameters to the Siemens Service Cen-

ter. Siemens experts are not only able to call the customers proactively and alert them to an impending problem, but can often immediately solve it remotely. Andrea Ganter, a technical assistant in Diagnostic and Interventional Radiology, tells of one such proactive telephone call: “Due to this call, we knew that our CT would work only for approximately another two days.” This gave the team enough time to shift patient appointments and program the necessary time for repairs without an involved onsite fault search. “Thanks to Guardian, the CT scanner was available again after four hours of repair time,” reports Ganter. Another advantage of remote monitoring is that Siemens can determine in advance, via SRS, which spare parts are required, so that the Customer Service Engineer (CSE) can bring the proper replacement parts with him. A few doors away, Ayser BirinciAydogan, a radiological assistant, is monitoring the scan of a 58-year-old man using the high-end, SOMATOM Definition Dual Source CT scanner. On the screen in the control room, the coronary vessels can be clearly recognized. The man came to UKT due to his family predisposition for coronary disease. Throughout all clinical operations, Guardian works unobtrusively in the background: through the proactive realtime monitoring of important system components such as X-ray tubes, detec-

“It is important to recognize errors as early as possible and not only after the system has gone down.” Professor Claus D. Claussen, MD, Medical Director, Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany

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difficult situation, a Siemens service technician quickly comes to UKT. “It is an advantage that the Siemens service organization is set up very well in the region and their technicians have a shorter distance to travel than other providers,” confirms her colleague, technical assistant Andrea Ganter. Based on the service agreement, the hospital’s own service technicians are not only trained by Siemens but also, for example, work together with Siemens service technicians in installing replacement parts. Thus, special technical knowledge is developed onsite, so a system can be restarted quickly in a serious situation.

Outstanding Remote Support and Onsite Service

“Siemens service technicians have often gone the ‘extra mile’ for us.” Ayser Birinci-Aydogan, Radiological Assistant, Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany

tor and image computer, system failures can often be avoided. “Our nightmare would be if our SOMATOM Definition were to go down in the core time of 10 a.m. to 2 p.m.,” says Birinci-Aydogan. Around 3 p.m. at the latest, the surgeons need the images in order to plan their procedures for the following morning. “For me, proactive service means predictability,” continues Birinci-Aydogan, as she glances away from the screen for a moment to clinic technician Jürgen Bahls, who hurries by. “Here in the hospital we have excellent technicians, and we are also very satisfied with

the Siemens service technicians and the remote support from the Siemens Service Center.” “So far, the Siemens service technicians have often gone the ‘extra mile’ for us – that is not something that one should take for granted,” Birinci-Aydogan reports. Often she already knows what to do as a result of her experience and involvement in the introduction of the SOMATOM Definition, but she also praises the knowledgeable contact persons at the other end of the telephone line and the possibility of remote support and repair. In the event of a

“Not only are we called back quickly by the UPTIME Service Center, but we also appreciate that the Siemens service technicians are committed and work competently,” says Ganter, who has worked at UTK for 13 years. “Due to the combination of proactive services and the onsite Siemens service technicians, planning reliability was greatly improved,“ stresses Ganter. Predictability is not only crucial for smooth workflow in radiology, but also for all further steps in the treatment: “And that applies not only to emergencies such as a patient with a lung embolism in intensive care,” says the technical assistant. “Every shift in our schedule as a result of a system failure results in 15 people waiting at the door. And follow-up appointments in the outpatient clinic, for example, must be rescheduled.” Then surgery schedules and the ordering of anesthesiologists as well as further treatments must be delayed. “Service is critical for workflow in radiology, from admission of the patient all the way to dismissal,” Ayser BirinciAydogan also adds. “If that service performance is proactive and competent as is the case with Siemens, that is all better,” she emphasizes.

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“Thanks to Guardian, the CT scanner was available again after only four hours of repair time.” Andrea Ganter, Technical Assistant. Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany

“Intelligent Handling” of Immense Quantities of Data SOMATOM CT systems provide UKT radiologists with a large number of data sets with high definition images. Those images support the radiologists with continuously more precise and reliable diagnostics, but in doing so, also supply large numbers of image data sets in order to facilitate more precise and reliable diagnostics. Professor Claussen sees “intelligent handling” of immense quantities of data as another essential condition of smooth workflow. During the past year, around 200,000 diagnostic examinations and more than 2,500 interventions were carried out in his department on CT and MR scanners as well as angiography systems. “On many days we generate close to 40 gigabytes of images,” says Horst Bock, who is responsible for the picture archiving and communication system (PACS) of the department. “Workflow must be integrated; it does not stop with the systems themselves or the PACS or the radiology information system. Above all, what counts today is medical know-how as well as workflow organization and opti-

mization in order to avoid long wait times and fast, competent diagnostics,“ summarizes Claussen. The professor sees radiology as a ‘service provider’ carrying out a service role. Innovative systems alone are by no means sufficient. In an increasingly intense and competitive environment, the development of a service culture is key – such as his team’s interaction with patients and colleagues in the hospital and also within the department. The medical director also expects excellent service from the medical technology providers and is not disappointed: „Here, we all appreciate the competent, preventive Siemens service.“

Proactive Real-time System Monitoring: Siemens Guardian Program Q

Q

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Further Information

Monitoring of potential system malfunctions and possible deviations from predefined values. Telephone call from Siemens UPTIME Service Center in the event of deviations. Problems often eliminated ‘remotely’ through the Siemens Remote Service platform. In the event of onsite deployment, Siemens service technicians can bring the proper replacement part on the initial visit. Reduction of unplanned system down time to a minimum. Improved appointment scheduling within and outside of the radiology department.

www.siemens.com/ guardian-program

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Customer Report: Upgrade from SOMATOM Plus 4 to SOMATOM Definition Delivers a new Picture of Health In 1998, the single-slice SOMATOM Plus 4 CT offered Saint Barnabas Ambulatory Care Center the most advanced imaging possible. Over the years, the unit’s capabilities were far surpassed, limiting its usefulness. But it remained a valuable trade-in for a SOMATOM Definition Dual Source CT. By Melanie J. Davis

“After we bought a second device, a SOMATOM® Sensation 16-slice scanner, the SOMATOM Plus 4 was simply taking up expensive floor space. When we had an opportunity to get even greater imaging capabilities with the SOMATOM Definition, we used the Siemens Elevate program to upgrade affordably by trading in the Plus 4. A third-party dealer wouldn’t have given us much for it, but we were very satisfied with the arrangements we made with Siemens,” says Barbara Richardson, Administrative Director of the Radiology Department at

Saint Barnabas Ambulatory Care Center, Livingston, NJ.

A Smart Business Decision The upgrade to the SOMATOM Definition Dual Source CT (DSCT) is part of the center’s efforts to provide state-of-theart imaging solutions. She says, “We constantly ask, ‘What’s the most we can do for our physicians? For our patients? For our employees?’ Having the best equipment is one answer to those questions. Dual Energy is emerging and we want to be part of the growth of that

“The SOMATOM Definition is not just a piece of equipment – it’s a great relationship between Siemens and us.” Barbara Richardson, Administrative Director of the Radiology Department at Saint Barnabas Ambulatory Care Center, Livingston, NJ

technology. We can now offer physicians that ‘special extra’, so we have a competitive edge.” Saint Barnabas Ambulatory Care Center provides outpatient services for nearby Saint Barnabas Hospital and other referring physicians, and is responsible for more than 90,000 imaging procedures a year. The decision to upgrade from the Plus 4 to the SOMATOM Definition was made after the staff extensively researched their options. They evaluated other vendors, and made the decision to lease the Siemens unit. “We’ve been with Siemens for a long time, and we have a great relationship with sales personnel and technicians. The SOMATOM Definition is not just a piece of equipment – it’s a great relationship,” says Richardson. Maureen Lowe, CT Supervisor, says the center is extremely pleased with the outcome. “You go back and forth on the dollars to make the best choice that will give you the payback that you want, and we’re happy with what we’re seeing. The Board of Directors is very excited with what the unit can do, and they realize that in diagnostic imaging, the new technology makes a difference.”

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Transition & Training Installing the SOMATOM Definition was both inexpensive and easy, with the work limited to “spiffing up” the room and making some electrical upgrades. Staff training consisted of Lowe and a senior evening staff member making two visits to the Siemens training center in Cary, NC so they could return and, led by a Siemens Clinical Education Specialist who was on-site in New Jersey for two weeks, train their own staff. “Two weeks was a lot of time for the specialist to be available to us, and it was helpful. I think the transition was very easy for us also because we were familiar with Siemens units and the syngo platform,” says Lowe. “Post-processing is so much simpler now because the raw data quality is so high that you’re not doing as much reconstructing. The amount of time we save in that aspect alone is impressive,” she adds.

New Clinical Applications Increase Patient Count Since the upgrade to the SOMATOM Definition, the center’s volume of procedures has steadily increased as word has spread among physicians about the system. Richardson says insurers’ reticence to approve multiple diagnostic CTs per patient will be offset by the increased type and quantity of procedures the center can conduct. The SOMATOM Definition’s speed accommodates many more patients during premium peak hours, and Siemens’ radiology information system made it easy to accommodate the increased patient load. Thanks to the upgrade, Lowe also anticipates an increase in the number of bariatric patients being scanned because the SOMATOM Definition’s large bore and increased power. Medical Director David Wilson, MD, adds: “Cardiology patients benefit because the Definition scans so quickly, it captures the heart’s action without the need for beta-blockers. We’re less dependent on the patient’s heart rate to get high-quality images. Before, those patients would have been told they

The decision to upgrade to the SOMATOM Definition was made after the staff extensively researched their options.

couldn’t be scanned or had to go someplace else.”

Dual Energy Impresses As important as the cardiology applications are with the SOMATOM Definition, Richardson says they were just a small part of the imaging center’s upgrade decision: “We bought it for the emerging technology we expect to see from Dual Energy. Now we can expand into a lot of areas.” Relatively little time has passed since the system was installed, yet Dual Energy is being used on a regular basis. One of the most successful of those

protocols has been scanning kidney stones, which the imaging center does at least once each day. “We are excited about this application because we can quickly determine whether the patient should be treated with medication or other interventions,” says Wilson. Wilson and his team all agree that the SOMATOM Definition has provided many benefits to Saint Barnabas Ambulatory Care Center.

Melanie J. Davis, Medical Writer

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syngo CT 2008G – New Software Release for SOMATOM Definition By Marion Meusel, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The latest enhancement for SOMATOM® Definition CT scanners is the new software version syngo CT 2008G. This new software will bring improved usability and the following new functionalities for the SOMATOM Definition. The highlights range from new Dual Energy applications to all new solutions for perfusion imaging and interventions:* The new syngo Dual Energy applications (Heart PBV, Brain Hemorrhage, Lung Vessels and Gout) will open new clinical fields.* With these applications, customers can take advantage of our 90 day free trial licenses.

The new Adaptive 4D Spiral* scan mode allows for whole organ coverage in perfusion CT as well as phase-resolved imaging up to 21 cm. Enabled by the volume projector, it applies a continuously repeated bi-directional table movement, moving the patient smoothly in and out of the gantry over the desired scan range. Interventional procedures are supported by i-Fluoro.* Fluoroscopic scans can be acquired with low-dose techniques and displayed in real time. For fastest workflow during interventions, scan modes can be switched on the fly with a single click. Key features are configurable layout screens,

an all-new Interventional Toolbar* and HandCARETM* for i-Fluoro to avoid direct X-ray exposure of the surgeon’s or radiologist’s hand during the intervention. SOMATOM Definition systems running on syngo CT 2007C will automatically receive the new software syngo CT 2008G** accompanied with comprehensive training on-site and supporting training material via e-learning CD.

*Optional components that need to be purchased separately. **Customers will be contacted by customer service.

CT Research Collaborations in China: a True Win-Win Situation By Reto Merges, CT Research Collaborations, Siemens Healthcare, Shanghai, China In China, the healthcare system is developing at a rapid rate alongside the economic growth. Innovative healthcare concepts are being implemented in all major cities of the country, therefore high-end CT systems are not a rarity anymore. At the same time, the scientific community strives for more international participation. Three years ago, Siemens

founded a dedicated team to support CT research in China. To be able to cater to the diverse needs of our Chinese partners, the team today consists of two radiologists and two engineers. It is a typical win-win situation because Siemens gets a unique insight into the customers’ needs in China and the collaboration partners gain direct access to the

technical knowledge, education and advice that they need in order to raise the scientific capabilities of their institutes. The activities extend from supporting research projects aimed at international publications to workshops on hot topics in radiology and scientific writing. Research topics cover a broad field of innovative CT applications, from Cardiac Imaging and CT Perfusion to Dual Energy CT. “The key is to help educate young researchers so that innovative healthcare delivery and research will go hand in hand in the future!” says Prof. Zheng Yu Jin, MD, Peking Union Medical College Hospital. A group of young researchers at the annual seminar on scientific writing.

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Recording of Hands-on Workshops at ECR 2008 By Heike Theessen, Business Unit CT, Siemens Healthcare, Forchheim, Germany At this year’s European Congress of Radiology (ECR) in Vienna, more than three hundred customers participated in the Hands-on Workshops organized by Siemens Healthcare. Clinical presentations by leading experts were followed by demonstrations of clinical cases during which participants were guided through the processing tools available for the syngo MultiModality Workplace platform. Sitting at one of the sixteen workstations, radiologists and technologists from over fifty countries had the opportunity to discover the capabilities of the syngo software.

Michael Lell, MD, University Hospital of the Friedrich-Alexander-University Erlangen-Nuremberg who led the session on Neuro-CT, rates these workshops to be very important, because they also serve to train the user with knowledge beyond application training. More about the clinical value of Siemens Hands-on workshops can be read under the link below. There you can also order the DVD with the recording of the ECR Hands-on workshops.

http://www.siemens.com/ somatomeducate

New e-Learning for CARE Dose4D By Claudia Lindner, Business Unit CT, Siemens Healthcare, Forchheim, Germany

CARE Dose4D™ and its real-time mA adjustment provide best image quality at the lowest possible dose. Every patient is different in terms of size, weight, and anatomy. Therefore CARE Dose4D was developed to provide fully automated, real-time, anatomy-based dose regulation. CARE Dose4D adapts the dose automatically to the specific anatomical characteristics of each individual patient to consistently deliver a user defined

800 mA

and customizable noise level. But how does it work exactly? With the new CARE Dose4D e-learning, CT-users can easily learn how to utilize CARE Dose4D most efficiently. The web based version can be accessed or the CD version can be ordered via the link below. This is only one e-learning tool out of many others offered by Siemens Healthcare. As part of the SOMATOM® Educate program “Life“, users benefit

81 mAs

from Siemens’ clinical e-learning opportunities – and experience the latest clinical results in the various fields of CT imaging.

http://www.siemens.com/ somatomeducate

210 mAs

20 mA

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1A

2

1B

1C

1 2 Adaptive 4D Spiral provides perfusion information not just for a limited section of the disease, but for the whole brain (Figs. 1A–C). ”Intervention Pro” supports spiral and sequential acquisition for interventional procedures with maximal flexibility (Fig. 2).

Free 90-Day Trial Licenses for Clinical Applications By Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

Trial License: Adaptive 4D Spiral Siemens’ unique Adaptive 4D Spiral moves beyond fixed detector limitations to provide full coverage of any organ in 4D. This overcomes the coverage limitation of a static detector design so the perfusion and dynamic coverage can be adapted to exactly the range needed. In stroke assessment, it provides the perfusion information, not just for a limited section of the disease, but for the whole brain,* so the physician is assured of a reliable assessment of the type and extent of cerebral perfusion disturbances. In addition, it allows tumor perfusion studies over the entire organ in both head and body,* enabling the radiologist to assess the perfusion and vascularization of tumors. Additionally, the Adaptive 4D Spiral enables the visualization and evaluation of

complex vascular structures by performing time-resolved angiographies with multiple phases. With this feature, for example, arterial and venous phases can be captured in a single acquisition and can then be evaluated time-resolved. The benefits of the Adaptive 4D Spiral can be experienced with a 90-day free trial. **

Trial License: Intervention Pro & Adaptive 3D Intervention For 90 days, at no cost, “Intervention Pro” can be tried, supporting guidance for interventional procedures with maximal flexibility and with minimal, singleclick effort. In addition, spiral sequence and fluoroscopic scan modes can be switched on the fly during interventions. A dedicated interventional toolbar supports the workflow with respect to table control and 2D/3D measurements. The additional option, Adaptive 3D Interven-

tion, further overcomes the limitations of conventional 2D-CT guidance, allowing for 3D visualization (MPR, VRT) and needle path planning.*** Thus, a more comprehensive visualization of needle position, needle path, and surrounding organs supports in difficult procedures. This is especially helpful when using oblique needle paths, for example, during RF ablation. Intervention Pro and Adaptive 3D Intervention can be tested risk free with a 90-day free trial.** * Maximum perfusion coverage depends on system configuration. **Minimum system requirements need to be fulfilled for these options to be available. Therefore the related Siemens representative should be asked to check the system configuration. ***Dual Monitor for in-room support highly recommended.

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Life

Clinical CT Posters Thanks to the excellent cooperation with our clinical partners, we now have a growing number of posters in the Clinical Poster Gallery. Perfect for the patient waiting room, the staff lounge or the reading room, these posters illustrate the wide range of images that are possible from a CT exami-

nation. They will help to educate staff and patients about the human anatomy as seen through a CT scanner. Key anatomy is clearly labeled, typical pathological findings are described and key features of the application are noted. To date we have the following posters available:

Q Q Q

CT Cardiac Anatomy CT Neuro Anatomy CT Colonography

Using the link, below a personal copy free of charge can be ordered. www.siemens.com/ct-poster

Frequently Asked Questions Q: How can I reduce my reading time in syngo Oncology? A: By using the powerful CAD tool in syngo Oncology after an automated detection of lung lesions, for example, several markers are listed which need to be reviewed. All the marked structures are numbered and listed in the Marker List. It is also possible to have several lesions from previous examinations or lesions

1

that are marked by the user him/herself. To save time, the space bar can easily be used to jump from one marker to the next (or the button “B” can be used to go back to the previous marker). After starting with marker number one, for instance, you only have to press the space bar to go straight to marker number two (Fig.1). Q: Can I change the default display for the Global Result Segment? A: Depending on your preference, it is

2

possible to convert the default display in the Global Result Segment from the VRT image to a MPR image. Under Options -> Configuration, you will find the “syngo CT Oncology” icon. Double click to open the configuration menu. On the second subtask card, you can select 2D for “Default Representation”. Then press “OK”. The next time when you open the syngo Oncology application the changes are applied (Figs. 2-3).

3

1 2 3 In the result view, the markers can easily be found to review tissue lesions (Fig. 1). In the configuration menu, the default display can easily be changed for the Global Result Segment (Figs. 2-3).

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Life

Clinical Workshops 2009 As a cooperation partner of many renowned hospitals, Siemens Healthcare offers continuing CT training programs. A wide range of clinical workshops keeps participants at the forefront of clinical CT imaging. Workshop Title

Dates

Location

Course language

Course director

Clinical Workshop on Cardiac CT

21.–23.01.09

Erlangen/Germany

English

Prof. Stephan Achenbach, MD

Clinical Workshop on Cardiac CT

15.–16.05.09 11.–12.09.09

Paris/France

English

Jean-Francois Paul, MD

Clinical Workshop on Cardiac CT

04.–06.02.09 08.–10.07.09 09.–11.11.09

Munich/Germany

English

PD Christoph Becker, MD Alexander Becker, MD

Clinical Coronary CTA Interpretation Course

12.– 13.03.09 14.– 15.05.09

Erlangen/Germany

English

Prof. Stephan Achenbach, MD

Clinical Training Course on Cardiac CT

21.–22.03.09 25.–26.07.09 21.–22.11.09

Kuching/Malaysia

English

Prof. Sim Kui Hian Ong Tiong Kiam, MD

Hands-on Workshop Cardio-CT

03.–04.07.09

Zürich/Schweiz

German

PD Hatem Alkadhi, MD

Clinical Workshop on State-of-the-Art Applications

27.–30.04.09 21.–24.09.09

Münster/Germany

English

PD Johannes Wessling, MD

Virtual CT-Colonography

27.–28.03.09 25.–26.09.09 20.–21.11.09

Berlin/Germany

German

Prof. Bernd Lünstedt, MD

Dual Energy Workshop

20.–21.02.09 17.–18.04.09

Forchheim/Germany

English

Thorsten Johnson, MD

Cardiac-CT Basics for Technologists

19.–20.03.09 06.–07.04.09

Forchheim/Germany

German English

Heike Theessen

Clinical Coronary CTA Workshop

05.-06.04.09 21.-22.06.09

Munich/Germany

English

PD Christoph Becker, MD Alexander Becker, MD

ESGAR CT-Colonography Workshop

02.–04.02.09

Harrogate/ United Kingdom

English

David Burling, MD Clive Kay, MD Stuart Taylor, MD

ESGAR CT-Colonography Workshop

17.–19.09.09

Stresa/Italy

English

Daniele Regge, MD

Clinical Workshop on Cardiac CT, CMIV

22.–24.04.09

Linköping/Sweden

Swedish

Anders Persson, MD

Clinical CT Colonography Workshop, CMIV 18.–20.03.09

Linköping/Sweden

Swedish

Ulf Björnlert, MD

Clinical PET/CT Basic Course

04.–06.11.09

KS Stockholm/Sweden

Swedish

Clinical Radiology Optimization Course, Norrköping

13.–15.05.09

Norrköping/Sweden

Swedish

Pia Björk/ Elisabeth Olsson

Clinical Workshop Advanced CT Application, CMIV

23.–26.09.09

Linköping/Sweden

Swedish

Petter Quick/ Peter Holmqvist

Workshop SOMATOM Definition for Hospital Physicist

18.–20.02.09

Stockholm/Sweden

Swedish

Lars Karlsson

In addition, you can always find the latest CT courses offered by Siemens Medical Solutions at www.siemens.com/SOMATOMEducate

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Scientific Photography Prize for Anders Persson The annual Lennart Nilsson Award this year goes to Professor Anders Persson, MD (Linköping University). The Swedish radiologist is honoured for his innovative 3D images depicting the human body internally. Using CT technology, he has provided new possibilities in forensic pathology.

The commendation is considered to be the world’s most prestigious award in scientific and medical photography. Read more about Persson’s methodology in the SOMATOM Sessions Magazine 22. www.siemens.com/ healthcare-magazine

Upcoming Events & Congresses Title

Location

Short Description

Date

Contact

Moscow Healthcare

Moscow, Russia

International Exhibition

Dec. 08 –12, 2008

www.zdravo-expo.ru/en

Arab Health

Dubai, UAE

Exhibition and Scientific Congress

Jan. 26 –29, 2009

www.arabhealthonline.com

25th Annual Computed Tomography 2009: The Cutting Edge

Orlando, USA

CME Course

Feb. 12 –15, 2009

www.hopkinscme.edu

ECR

Vienna, Austria

Exhibition and Scientific Congress

March 06 –10, 2009

www.ecr.org

ACC

Orlando, USA

Exhibition and Scientific Congress

March 29 –31, 2009

www.acc09.acc.org

GEST

Paris, France

Global Embolization Symposium and Technologies

April 15 –18, 2009

www.gest09.eu

ITEM

Yokohama, Japan

Internat. Tech. Exhib. of Med. Imaging

April 16 –19, 2009

www.j-rc.org

Deutsche Gesellschaft für Kardiologie

Mannheim, Germany

75th Annual Meeting

April 16 –18, 2009

www.dgk.org

ICNC

Barcelona, Spain

Nuclear Cardiology and Cardiac CT

May 10 –13, 2009

www.icnc9.org

11th International Symposium on Multidetector-Row CT

San Francisco, USA

Stanford CME Course and Exhibition

May 19 –22, 2009

radiologycme.stanford.edu

DRK

Berlin, Germany

National Scientific Congress

May 20 –23, 2009

www.roentgenkongress.de

Valencia, 2nd World Congress of Thorac. Imag. and Spain Diagn. in Chest Disease (WCTI)

Scientific Congress

May 30 –June 02, 2009

www.2wcti.org

In addition, you can always find the latest CT courses offered by Siemens Medical Solutions at www.siemens.com/SOMATOMEducate

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Subscription

Siemens Healthcare – Customer Magazines Our customer magazine family offers the latest information and background for every healthcare field. From the hospital director to the radiological assistant – here, you can quickly find information relevant to your needs.

Medical Solutions Innovation and trends in healthcare. The magazine, published three times a year, is designed especially for members of the hospital management, administration personnel, and heads of medical departments.

AXIOM Innovations Everything from the worlds of interventional radiology, cardiology, fluoroscopy, and radiography. This semiannual magazine is primarily designed for physicians, physicists, researchers, and medical technical personnel.

MAGNETOM Flash Everything from the world of magnetic resonance imaging. The magazine presents case reports, technology, product news, and how-to’s. It is primarily designed for physicians, physicists, and medical technical personnel.

News Our latest topics such as product news, reference stories, reports, and general interest topics are always available at www.siemens.com/ healthcare-news

SOMATOM Sessions Everything from the world of computed tomography. With its innovations, clinical applications, and visions, this semi-annual magazine is primarily designed for physicians, physicists, researchers, and medical technical personnel.

Perspectives Everything from the world of clinical diagnostics. This semi-annual publication provides clinical labs with diagnostic trends, technical innovations, and case studies. It is primarily designed for laboratorians, clinicians and medical technical personnel.

For current and older issues and to order the magazines, please visit www.siemens.com/healthcare-magazine

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Editorial

Imprint

“Lowest radiation dose is important to physicians and patients. It’s important to us.” Sami Atiya, PhD, Chief Executive Officer, Business Unit CT, Siemens Healthcare, Forchheim, Germany

SOMATOM Sessions – IMPRINT © 2008 by Siemens AG, Berlin and Munich All Rights Reserved Publisher: Siemens AG Healthcare Sector Business Unit Computed Tomography Siemensstraße 1, 91301 Forchheim, Germany Chief Editors:

E. Hendrich, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

M. Remy-Jardin, MD, PhD, University Center of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille, France

M. Higashi, MD, Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan

P. Schramm, MD, Department of Neuroradiology, University of Göttingen, Göttingen, Germany

R. Hoffmann, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany T. Jakobs, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany S. Kanzaki, MD, Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan K. Kichikawa, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan S. Kitano, MD, Department of Radiology, Nara Medical University, Nara, Japan

Monika Demuth, PhD (monika.demuth@ siemens.com)

Stefan Wünsch, PhD (stefan.wuensch@ siemens.com)

Responsible for Contents: André Hartung Editorial Board: Andreas Blaha, Andreas Fischer, Thomas Flohr, PhD, Klaudija Ivkovic, Axel Lorz, Jens Scharnagl, Heiko Tuttas, Alexander Zimmermann

A. Megibow, MD, MPH, FACR, New York University Medical School, New York, USA

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The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary. Partial reproduction in printed form of individual contributions is permitted, provided the customary bibliographical data such as author’s name and title of the contribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article. We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and information are always welcome; they are carefully examined and submitted to the editorial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

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Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system. SOMATOM Sessions with a total circulation of 35,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their application as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and discusses their clinical potential. The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher. The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the practice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Solutions to be used for any purpose in that regard.

Institution

J. Remy, MD, University of Center Lille, Department of Thoracic Imaging, Hospital Calmette, Lille, France

Department

J. Hausleiter, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

Printers: Farbendruck Hofmann, Gewerbestraße 5, 90579 Langenzenn, Printed in Germany

Function

M. Reiser, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

Layout: independent Medien-Design Widenmayerstrasse 16, 80538 Munich

Title

M. Godoy, MD, Department of Radiology, New York University Medical Center, New York, USA

Production: Norbert Moser, Siemens AG, Healthcare

Name

K. Nikolaou, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

Peter Aulbach; Steven Bell; Andreas Blaha; Joachim Buck, PhD; Jan Chudzik; Ulrike DrägerKlar; Ivo Driesser; Carolin Emmert; Inga Fötsch; Tanja Gassert; Christoph Hachmöller, MD; Carolin Knecht; Rami Kusama; Claudia Lindner; Reto Merges; Marion Meusel; Kerstin Putzer; Rainer Raupach, PhD; Holger Reinsberger; Peter Seitz; Katja Stöcker; Heike Theessen; Stefan Wünsch, PhD; Claudette Yasell; all Siemens Healthcare

Street

H. Naito, MD, PhD, Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan

Photo Credits: Peter Rigaud/Shotview, Jez Coulson, Tina Ruisinger, Stephan Sahm, Chris De Bode

Postal Code

D. Naidich, MD, Department of Radiology, New York University Medical Center, New York, USA

Willi Kalender, PhD, Director of the Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany

City

R. Finzel, Department of Neuroradiology, University of Göttingen, Göttingen, Germany

N. Marugami, MD, Department of Radiology, Nara Medical University, Nara, Japan

Catherine Carrington, freelance author Melanie J. Davis, medical writer Tony DeLisa, freelance author Sameh Fahmey, medical and scientific journalist Hildegard Kaulen, PhD, freelance scientific journalist Oliver Klaffke, freelance scientific journalist Tim Schröder, freelance scientific journalist Rita Wellens, PhD, medical writer and clinical research consultant

State

J. Fielding, Department of Radiology, Angliss Hospital, Upper Ferntree Gully, Melbourne VIC, Australia

S. Martinoff, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

T. Taoka, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan

Country

B. Beyer, MD, Department of Surgery, University of Munich, Campus Großhadern, Munich, Germany

T. Löffler, MD, Department of Surgery, University of Munich, Campus Großhadern, Munich, Germany

W. Sommer, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

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Authors of this Issue: S. Achenbach, MD, Department of Cardiology, University of Erlangen-Nuremberg, Erlangen, Germany

A. Kohli, MD, Department of Radiology, Breach Candy Hospital Trust, Mumbai, India

“The new scanner is a true revolution. We never before dared to scan with such a low dose and such a high speed.”

17.11.2008 7:53:09 Uhr

SOMATOM Sessions 23

Through a combination of unprecedented speed and innovative dosereduction features, the new SOMATOM Definition Flash offers patients a healthier CT scan.

Siemens AG Healthcare Sector Henkestraße 127 91052 Erlangen Germany Phone: +49 9131 84 - 0 www.siemens.com/healthcare

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Local Contact Information

Siemens AG Medical Solutions Computed Tomography Siemensstraße 1 91301 Forchheim Germany Phone: +49 9191 18 - 0 www.siemens.com/healthcare

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November 2008

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Global Siemens Healthcare Headquarters

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SOMATOM Sessions The Difference in Computed Tomography

Issue Number 23/November 2008 RSNA Edition | November 30th – December 05th, 2008

Cover Story SOMATOM Definition Flash Dual Source CT: Leaving Dose Behind Page 6

News Dual Source CT on Scientific Center Stage Page 14

Business RSNA Edition

Global Siemens Headquarters

As Radiation Dose Goes Down, Attractiveness of CT Rises Page 20

Clinical Outcomes

Latin America: Siemens S.A. Medical Solutions Avenida de Pte. Julio A. Roca No 516, Piso 7 C1067ABN Buenos Aires Argentina Phone: +54 11 4340 - 8400 www.siemens.com/healthcare

Coronary CTA with Flash Spiral Scanning in 300 msec Scan Time Page 26

USA: Siemens Medical Solutions U.S.A., Inc. 51 Valley Stream Parkway Malvern, PA 19355-1406 USA Phone: +1-888-826 - 9702 www.siemens.com/healthcare

CT put to the Test Page 56

Science

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