Lecture 3 September 20th-radiology

1RADIOLOGY – SEPTEMBER 20TH, 2007 Page 8 LUMBAR OBLIQUES Nose is left transverse process Pedicle is eye of Scotty dog Superior articular process: ear Inferior articular process: front leg Neck is pars interarticularis (The area of bone between the superior and inferior articular processes) Space between ear and leg of one above is facet joint. If you draw a line to split the tail and hind leg from the rest of the dog, this is the divider between left and right. Everything to the left is ipsilateral to the marker (left). Everything to the right is contralateral to the marker (Right) If the patient is rotated 45 degrees, will have best chance of seeing Scotty dog! If the marker said “R”, the nose of the Scotty dog would be the right transverse process. Quiz: Name the view: Lumbar Oblique (because you can see the Scotty dog) Red circle: Right pedicle of L3 Two green lines: Facet joint between superior articular process of L2 and inferior articular process of L1 on the right side. Turquoise upside-down triangle: Superior articular facet on the right, L4 Purple triangle: inferior articular process on the right, L4 Orange line: Sacro-iliac joint on the right (one of the SI joints is always facing the beam in oblique view: can look right down the joint Blue lines: pars interarticularis on R side, L3. Page 10 THORACIC SPINE Slide 2: AP and lateral are favourite views. Arms get in the way of lateral thoracic. Always in the way of upper thoracic. “Swimmer’s view” allows you to asses between C7-T4 Thoracic spine: include bottom of C7, top of L1 Diaphragm moves down during inspiration: gets it out of the way. Always darker on T1-T4 because we are thinner there than towards the lower part of the T spine. Can get filter to even out the density. T1 has 1st rib. Landmark. Collimation: shortening the beam from side to side to eliminate the lungs. Overpenetrated: too light, under=too dark. Patient leaning? Might be because they are trying to avoid painful position. Slide 3: Rib contacts body and transverse process. Can see whitening of bone on TVP where bones overlap Semi-circles on either side of bodies: laminae Ovals in centre are spinous processes. (the nose between the eyes). Remember that the spinous processes angle downwards. The spinous processes of T7 is showing up on T8. As you get to the lower thoracic spine, they appear closer to the inferior edge of the body of the vertebrae it belongs to. Count the spinous processes from the bottom up? TVP of cervical spine point downwards, the TVPs of the thoracic spine point downwards. Where you see two pointing to each other, this is the C-T junction. Sternum is superimposed on spine: don’t see it because it is thin. Clavicles: Small rotations will change position dramatically. Can see trachea: air filled. Can see how it narrows as it moves into pharynx. Follow trachea downwards and you can see where it splits into primary bronchi. Right bronchus is direct continuation of the trachea. See gastric air bubble below diaphragm: this is the left side. Line that is just lateral to spine: paravertebral soft tissue stripe: Muscles and ligaments. If this bulges outwards, secondary sign of inflammation, fracture. Lateral to the first stripe you can see is the descending aorta. RADIOLOGY SEPTEMBER 20TH, 2007 – PAGE 1

Magenblasse: stomach bubble See shadow of the heart on the left side Page 11 Spinous process usually goes 1.5 segments downwards. Space between 2 lamina = interlaminar space. Slide 2: T/L spot view Thoraco-lumbar junction. Narrowed view to specific region. Slide 3: Arms are always in the way for upper spine, no matter what you do. 2 distinct diaphragms and heart. Heart sits on top of left diaphragm Page 12: Alignment: Posterior vertebral body line is George’s line Bones: Diaphragm dips down (at bottom/left of film) at T12 level. Cartilage: Disk spaces Skip “swimmer’s view” Page 13: Emergency room: may just do AP and Lateral No Scotty dogs in the obliques APOM: this may be uncomfortable for the patient. Can see lots of detail in this film. Lateral masses of C1, dens, half of foramen magnum, condyles of C0, atlanto-axial joints Page 14: TVPs of C2 are under teeth. Can see articular facets of C2 TVP of C1: can see it between rows of teeth. Transverse lines are anterior and posterior arches of C1. Alignment: Space adjacent to dens: para-odontoid space Para-odontoid notch: at base of dens Para-odontoid space: widens with rotation. See space on right is wider in this film. Probably just rotation. If it is a fracture, this usually happens bilaterally. Purple lines: should see lateral mass of C1 lining up with articular pillars of C2 Bone: Dens Tvp lateral mass Small margin of pedicles: they are in the sagittal plane so you can see them, Spinous process of c2 Page 15: Arches of C1: the higher one is USUALLY the anterior arch Spaces; disk spaces, paraodontoid spaces: are they equal? Quiz: Tomogram: tomography is an old technology: pivot around point of interest, blurry elsewhere Note: both lateral massesdo not line up with articular pillars. Called burst fracture: they fell on their head or something fell on their head, burst bone. Page 16: “elephant ears” on either side of trachea: epiglottic valeculae. Pouches that food, marbles gets caught in. Uncinate processes: U shape to bodies of vertebrae. Points at lateral sides of body. Forms unco-vertebral joints. Lateral margin of articular pillars is sine-wave shapes. Called the articular pillar border, or the sinusoidal border of the articular pillars. RADIOLOGY SEPTEMBER 20TH, 2007 – PAGE 2

Slide 2: Pedicles in cervical spine are best viewed from oblique angle. Look at circles that are lateral to the spinous processes. C7 does not contain the vertebral artery and vein Cervical spinous processes are bifed. Exception is C7 which is not split. In cervical spine, articular pillar is structure formed by superior and inferior articular facet. The bone between these facets in the lumbar spine is called the pars interarticularis. Slide 3: Spinous process of C4 Inferior body margin of C3 Right pedicle of C6 Right C7 lamina Page 17: Yellow: Left TVP of T1 Left TVP of T2 Right rib head and neck where they articulate with T2 (neck articulates with TVP of T1) Costotransverse articulation of t1 Rib tubercle on right of rib 1 Bifed spinous process of c4 Trachea Slide 2: Uncinate processes are cat ears Slide 3: Green line: Sinusoidal border Soft tissue: where trachea is very narrow, this is where vocal chords are. Blue dotted lines: calcified thyroid cartilage: always at C4/C5 level. Don’t confuse with calcium in thyroid gland! You don’t want to see this! Calcified thyroid cartilage is normal. Page 18: Lateral cervical spine positioning: Want to go from top of ear: see bottom part of skull. Page 19: See anterior tubercle of C1, posterior arch. Can’t see much beyond this and dens in anterior tubercle. On lateral view, can see shape of articular pillars well. U-shapes anterior to articular pillars: cervical gutter of transverse processes Posterior to articular pillars is laminae Spino-laminar junction: between spinous process and lamina. Anterior tubercle is typically a D shape In front of posterior tubercle of C1 is white line: this is where posterior arches join posterior tubercle. Superior posterior margins of lateral masses Page 20: ADI: atlanto-dental interspace: space between the “d shape and the dens” Children: space appears bigger because it contains cartilage that hasn’t formed into bone yet. This space should never vary because the atlas and axis are fused by the transverse ligament of the dens. THIS WEEK’S FILMS WILL STAY UP IN THE DRY LAB FOR ANOTHER WEEK (?) CHECK THEM OUT IF YOU HAVEN’T ALREADY AS OUR FINAL EXAMS MAY BE BASED ON THIS MATERIAL. IF YOU HAVEN’T SUBMITTED YOUR TOPIC TO DR. ADAMS, PLEASE DO SO ASAP.

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