Pleura And Mediastinum

Radiology (Dra. Bandong) Pleura, mediastinum… 05 July 2008

Pleura Anatomy o a space within the thoracic cavity o bounded by: anterior sternum posterior vertebral bodies superior thoracic inlet inferior diaphragm lateral parietal pleura o divided into compartments by drawing a line from the sternal angle to the 4th thoracic intervertebral disk space area above superior compartment area below inferior compartment o anterior o middle o posterior CT SCAN o is the imaging modality of choice for diagnosis, staging, and follow up of patients o offers the advantage of better localization and characterization of the disease process o it can demonstrate compression and involvement of the adjacent structures in the mediastinum better than plain films. Normal Thymus o Lies in a retrosternal location behind the manubrium o Commonly seen anterior to the proximal ascending aorta and distal superior vena cava o Size of a normal thyroid is largets between 12-19 years of age. Anterior mediastinal compartment o o

Anteriorly by the sternum Posteriorly by the pericardium, aorta, and brachiocephalic vessels

Masses situated predominantly in the anterior mediastinal compartment (AMC)

1C ng 3B (jassie, viki, candz..ung iba support group..hehe)

A mass is considered to lie in the AMC when it is situated in the region anterior to the line drawn along the anterior border of the trachea and posterior border of the heart

o o o

Widened mediatinum Loss of cardiac silhouette Intact silhouette of descending aorta

o

Retrosternal area is filled with mass density

Anterior Mediastinal Mass o Thymus Thymoma – Most common Thymic cyst Thymolipoma Thymic carcinoid Thymic hyperplasia o Lymphoma o Germ cell tumor Teratoma Seminoma Shoriocarcinoma o Thyroid Goiter Tumor o Mesenchymal tumors Leiomyoma Liposarcoma o Hemorrhage 1 of 16

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

NOTES: Mediastinal mass: mass: o Margins are smooth Spiculated margins o Bilateral Unilateral o Loss of cardiac silhouette

Pulmonary o

LYMPHOMA

o

Anterior mediastinal mass Thymoma Teratoma Thyroid nodule / goiter Lymphoma THYMOMA o Most common neoplasm of the anterior mediastinum o 30-35% are malignant o Commonly occur in patients >40y/o o Asymptomatic o CXR: Found in anterior mediastinum to the ascending aorta above the right ventricular outflow tract and main pulmonary artery Maybe situated as low in the mediastinum as the cardiophrenic angles o CT(Benign) Well demarcated masses with homogenous density Uniform contrast enhancement Have areas of decrease attenuation Punctuate or ring like calcifications o CT (Malignant) Heterogenous attenuation May obliterate adjacent mediastinal fat May detect pleural spread

2 types of lymphoma: Hodgkin’s (HL) o Bimodal age distribution—25-30 y/o and >70 y/o o 67% intrathoracic involvement (anterior/ superior mediastinal and hilar adenopathy) o 15-40% pulmonary involvement by: Direct extension form involved nodes Pulmonary nodules Parenchymal consolidation Pleural effusion Sternal erosions Non Hodgkin’s (NHL) o 4x more common than HL o 3rd most common childhood malignancy o More frequently fatal than HL o Middle medisatinum – most frequently involved o Posterior mediastinum and cariophrenic angles can be altered o Appears as a single large conglomerate o Other common nodal signs involvement include Lung parenchyma Pleura Pericardium Germ Cell Tumors o o o

most are found in the anterior mediastinum 20-40 years Divided into seminomatous neoplasms (seminoma) non seminomas

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Seminomatous neoplasm (Seminoma) o Most common germ cell tumor o most common primary malignant cell tumor o less aggressive o secrete low levels of HCG o On CT: large masses with sharply demarcated borders o Homogenous attenuation but may have hemorrhage and necrosis

Non Seminomatous neoplasm o More aggressive o Secrete high levels of fetoprotein and / or HCG o Teratoma Most common non seminomatous tumors Most common mediastinal germ cell tumor Benign: mature teratoma MATURE TERATOMA CXR: large, well demarcated, rounded masses

Located anterior to the root of the aorta and main pulmonary artery Calcification, ossification or even teeth may be visible CT: large cystic mass Thick, encapsulated wall May enhance May contain curvilinear calcifications

MALIGNANT TERATOMA CXR: more lobulated in outline Rarely has calcifications and never has fat density Metastasize to the lungs, bones or pleura CT: typical mass has irregular border with thick capsule Enhances with IV contrast Adjacent fat planes are obliterated

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Extreme local invasion is common *In CT scan, this can be distinguished from thymoma and seminoma.

Middle and Posterior Mediastinum (MMC / PMC) Masses predominantly in the MMC and PMC

A lesion can be considered to properly lie in the MMC or PMC when it is located between a line drawn through the anterior aspect of the trachea and posterior aspect of the heart and the line drawn through the anterior margins of the vertebral bodies NOTES: Posterior lesion – 20 to osseous; sarcoma involving the vertebral column Middle lesion – esophagus, bronchogenic cyst Middle Mediastinum Boundaries by posterior margin of anterior division and anterior margin of posterior division (malamang!) Normal structures

Heart and pericardium Ascending and transverse aorta Brachiocephalic vessels SVC and IVC Main pulmonary vessels Trachea and main bronchi Lymph nodes Differential diagnosis of middle mediastinal masses Lymphadenopathy Bronchogenic cyst Vascular abnormalities Pericardial cyst Tracheal tumor Most common: aneurysm Posterior mediastinum Boundaries bounded anteriorly by the posterior margin of the pericardium and great vessels and posteriorly by the thoracic vertebral bodies Normal structures Descending thoracic aorta Esophagus Thoracic dust Azygous and hemiazygous Autonomic nerves Lymph nodes Fat Differential diagnosis Neurogenic tumors Paravertebral abnormalities Vascular abnormalities Esophageal abnormalities Lymphadenopathy Neurenteric cyst Bochdalek’s hernia Extramedullary hematopoeisis *It is difficult to delineate middle to posterior mediastium. CASE: An 87 year old woman presents with dysphagia Radiographs show a homogenous mass in the middle / posterior mediastinum extending from the level of the aortic arch to the diaphragm and displacing the esophagus to the right (residual contrast is evident in the esophagus from a barium swallow)

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

A CT scan just below the level of the carina reveals a hematogenous soft tissue mass with a central area of low attenuation (A). Note the markedly compressed esophagus (B). It is not possible to discern whether the mass is arising from the wall of the esophagus or the adjacent mediastinum. There is an incidental finding of calcified brachial plates (C)

Contrasted Chest CT demonstrating heterogenous appearing post mediastinal mass with punctuate calcifications which appears to extend into the neural foramina. Non contrasted chest CT demonstrating heterogenous appearing post. Mediastinal mass with punctuate calcifications which appears to extend into the neural foramina (see picture below) *With contrast, there is enhancement of blood vessels and vice versa in non-contrast.

NEUROGENIC TUMORS o o o o

Age: occur in young patients in the first 4 decades of life (young???) Gender: males and females equally affected Round, homogenous with widening of the neural foramen MRI: slightly brighter than muscle on T1 Very bright on T2 homogenous enhancement following gadolinium demonstration

Neuroblastoma

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

CARDIAC IMAGING LECTURE o o o o

Tricuspid valve regulates blood flow between RA and RV Pulmonary valve controls blood flow from right ventricle into the pulmonary artery which carry blood to the lungs to puck up O2 Mitral valve lets O2 rich blood from lungs to pass from LA to LV Aortic valve opens the way for O2 rich blood to pass from LV to the aorta, the largest artery, where it is delivered to the rest of the body

allow blood to pass through the ventricles. During systole, the ventricles contracts triggering the atria to contract. The RA empties its contents into RV. The tricuspid valve prevents blood from flowing back into the RA. NOTES: Common Imaging modalities: a. Ionizing radiation – Radiography, CT, Nuclear Scintigraphy b. Non-ionizing radiation – MRI and 2D Echo

Cardiac Borders: (see picture above) Right side – SVC and RA Left side – aorta, aortic arch, pulmonary artery, LA, LV During Diastole, atria and ventricles are relaxed and the AV valves are open. DeO2ated blood from the SVC / IVC flows to the RA. The open ______ atrioventricular valves

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

This sagital MRI shows the mid-section of the LV, defining the interventricular septum of the myocardium and the lateral wall. The right ventricle and its outflow tract are seen as one continuous structure. Calcium Score o Identifies calcification of arteries o Screening o Increased calcification = MI

coronary

This coronal MRI shows a somewhat anterior plane of the heart. The RV and proximal pulmonary artery is well defined. Portions of the SVC and RA are also visible.

CARDIO THORACIC RATIO • •

• This axial MRI shows the main and right pulmonary artery crossing under the aortic arch (medyo malabo, pxenxa)

The widest diameter of the heart compared to the widest internal diameter of the rib cage Get the diameter of the heart then divide it to the diameter of the entire thoracic area within the confines of the thorax (ribs not included) Normal Cardio-thoracic ratio: o Adults - < 0.5

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

CARDIAC CONTOURS

o

Children – 0.55

o

Sometimes, CTR is more than 50% BUT heart is normal Extracardiac causes of heart enlargement Portable AP films Obesity Pregnancy Ascites Straight back syndrome Pectus excavatum CTR is less than 50% BUT heart is abnormal Obstruction to outflow of the ventricles Ventricular hypertrophy Must look at cardiac contours Here is an example of a heart which is < 50% of the CTR, in which the heart is still abnormal. This is recognized because there is an abnormal contour to the heart.

Cardiac contours: • Ascending aorta o Enlargement 20 to atherosclerosis o Enlargement is called: Double density sign • Left atrium • Aortic knob o Normal: not > 0.35 mm o If enlarged, there is atherosclerotic aorta o >0.5 cm: aneurysm • Pulmonary artery o Congenital disease o Dilatation of artery

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

DOUBLE DENSITY

OF

LA ENLARGEMENT

Main Pulmonary Artery The next bump down is the main pulmonary artery and is the keystone of this system

Two shadows: the yellow arrow pointing to the LA and the red arrow to the RA, overlap each other where the indentation between the ascending aorta and the right heart border meet.

Aortic knob o The first bump on the left side o Can be measured from the lateral border of air by the trachea to the edge of the aortic knob. o Enlarged by Increased pressure Increased flow Changes in the aortic wall

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Two major classifications o Main pulmonary artery projects beyond the tangent line Increase pressure Increase flow Left atrial enlargement Concavity where LA will appear on the L side when enlarged

NOTES: Small pulmonary artery: TOF, Truncus arteriosus Apex of ventricle goes down: Enlargement of left ventricle Apex of ventricle goes up: Enlargement of right ventricle o

Which ventricle is enlarged? If heart is enlarged and main pulmonary artery is big RV is enlarged

Main pulmonary artery more than 155mm away from the tangent line. Because MPA is small or absent Because tangent line is being pushed away from the MPA Examples: small pulmonary artery Truncus arteriosus Tetralogy of fallot

Five states of the Pulmonary Vasculature: • Normal (more vessels should be seen in inferior part of the lungs); with enlargement of upper lobe, there is cephalization. • Pulmonary venous hypertension • Pulmonary arterial hypertension • Increased flow • Decreased flow What we’re going to evaluate

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Right descending pulmonary artery Distribution of flow in the lungs Upper vs. lower lobes Central vs. peripheral

Right Descending Pulmonary Artery o Serves right, middle and lower lobes

Normally should not be more than 17mm in diameter. (Diameter is measured before the bifurcation)

*Central Vs. Peripheral distribution of flow: divide lungs vertically into 3. Outer 2/8: here, you seldom see vascular markings. If present, there is congestion. 2. Pulmonary Venous Hypertension o Has cephalization (more vessels in upper lobes than lower lobes) o Increased vascular markings

1. Normal Distribution of flow (U / M/ L lobes) o In erect position, blood flow to the bases is > than flow to the apices o Size of vessels at the bases is normally > than the size of vessels at apex o You cant measure the vessels at the left because the heart blocks them

3. Pulmonary Arterial hypertension o RDPA > 17 mm o More central vessels are dilated o Dilatation of right descending pulmonary artery o Main pulmonary artery projects beyond the tangent line

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

o o

Rapid cutoff on size of peripheral vessels relative to the size of central vessels Central vessels appear to large for size of peripheral vessels which come from them = Pruning

5. Decreased flow o Unrecognizable most of the time o Small hila o Fewer than normal blood vessels o No vessels in lower lobes (which is normally present)

4. Increased flow o Distribution of flow is maintained as normal o Gradual tapering from central to peripheral o L lobe bigger than U lobe

CONGESTIVE HEART FAILURE coronary artery disease Hypertension Cardiomyopathy Valvular lesion AS, MS L to R shunts o Clinical: left sided heart failure: Shortness of breath Paroxysmal nocturnal dyspnea Orthopnea Cough right sided heat failure: Edema Left Atrial Pressure Correlated with pathologic Findings Normal 5-10 mm Hg Cephalization 10-15 mm o

Causes:

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Hg 15-20 Hg Interstitial 20-25

Kerley B lines Pulmonary edema Pulmonary edema

mm

Alveolar >25

*Normal pulmonary capillary hydrostatic pressure: about 7 mmHg Normal colloid oncotic pressure: 11 mmHg Kerley A lines – near hilum, longer B lines Kerley B lines – sign of interstitial edema, located in the bases Kerley C lines – does not exist Keeping lungs dry

Pulmonary Interstitial Edema • Fluid present in minor fissure • Linear opacities in bases: Kerley B lines • X-ray Findings o Thickening of the interlobular septa Kerley B lines o Peribronchial cuffing Wall is normally hairline thin Thickening of the fissures Fluid in the subpleural space in continuity with interlobular septa Pleural effusions o

•

Kerley B lines o B = distended interlobular septa o Location and appearance Bases 1-2 cm long Horizontal in direction Perpendicular to pleural surface

Kerley B lines are short, white lines perpendicular to the pleural surface at the lung base Kerley A and C lines o A = connective tissue near bronchoaretrial bundle distends o Location and appearance Near hilum Run obliquely Longer than B lines o C = reticular network of lines

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

**C lines probably don’t exist (huh??)

o o o

Fluid collects in the subpleural space Between visceral pleura and lung parenchyma Normal fissure is thickness of a sharpened pencil line Fluid may collect in any fissure Major, minor, accessory fissure, azygous fissures Minor fissure: thickened fluid Pleural effusion: there is obliteration of costophrenic sulcus

Kerley A and C lines form a pattern of interlocking lines in the lung PERIBRONCHIAL CUFFING o o o

Interstitial fluid accumulates around the bronchi Causes thickening of the bronchial wall When seen on end, it looks like little “doughnuts”

PLEURAL EFFUSION Laminar effusions collect beneath visceral pleura In loose connective tissue between lung and the pleura Same location for “pseudotumors” o

Peribronchial cuffing results when fluid thickened bronchial walls become visible producing doughnut- like densities in the lung parenchyma Fluid in the fissures

Laminar pleural effusion can be difficult to see. Aerated lung should normally extend to the inner margin of the ribs. The white band of

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

fluid seen here (white arrow) is a laminar effusion separating aerated lung from the inner rib margin CEPHALIZATION o o o o

If hydrostatic pressure >10mm Hg fluid leaks into the interstitium of the lung Compresses lower lobe vessels first Perhaps because of gravity Resting upper lobe vessels ‘recruited” to carry more blood Upper lobe vessels increase in size relative to the lower lobe

Cephalization means pulmonary venous hypertension. As long as the person is erect when the chest X-ray is obtained PULMONARY EDEMA Types o Cardiogenic o Neurogenic o Increased capillary permeability Congestive heart failure Xray patterns 1. Interstitial o Thickening of the interlobular septa Kerley b lines o Peribronchial cuffing Wall in normally hairline thin o Thickening of the fissures

o o

Fluid in the subpleural space continuity with interlobular septa Pleural effusions Cephalization

in

2. Alveolar o Acinar shadow o Outer third of the lung frequently spared Bat-wing or butterfly configuration o Lower lung zones more affected than upper o Massive pleural effusion

In pulmonary alveolar edema, fluid presumably spills over from the interstitium to the air spaces of the lung producing a fluffy configuration “bat wing” like pattern of disease Pulmonary Alveolar edema Clearing o Generally clears in 3 days or less o Resolution usually begins peripherally and moves centrally Differential diagnosis Cardi ac lines 30%

Renal

ARDS

30%

None

of Even 90%

Centr al 70%

Peripher al in 45% Even in 35%

Kerley B and peribronchial cuffing Distribution Pulmonary Edema

RADIOLOGY – Pleura and mediastinum by Dra. Bandong

Air bronchograms

20%

20%

70%

Pleural Effusions

40%

30%

10%

CHF in Chronologic Sequence (e2 po ung last topic, pero hindi n nmin nkuha..kung meron sa inyong may notes pshare nlng. EXCLUSIVE WONCEE TRANS …effort as in…