Vertebral Column 4

Question 1

what are the diagnositc imaging options of the vertebral column

Answer 1

1. radiography
2. computed tomography (CT)
3. magnetic resonance imaging (MRI)
4. nuclear scintigraphy
5. ultrasound

Question 2

what are the most radiographic views taken of the vertebral column

Answer 2

1. lateral view
2. ventrodorsal view

Question 3

what are the labelled parts

Answer 3

1. dorsal spinous process
2. transverse processes
3. vertebral body
4. invertebral foramen
5. articular facets
6. intervertebral disc space

Question 4

what are the drawbacks of radiographs

Answer 4

superimposition

the dorsal spinous processes can be seen in lateral view but are superimposed in ventrodrosal

transverse processes can be seen in ventrodorsal view but less in lateral

not good for soft tissue –> invertebral disc space appears dark or radiolucent gap, cant see cord

Question 5

what is a myelogram

Answer 5

injection of contrast medium into vertebral canal (subarachnoid space)

outlines spinal cord

Question 6

where can the constrast medium for myelogram be injected

Answer 6

1. cisterna magna –> occipital crest of skull, dorsal spinous process of axis, transverse processes or wings of atlas, needle is introduced midline
2. lumbar region –> cranial to dorsal spinous process of L6

Question 7

what is the bone window

Answer 7

CT image produced can be altered to enhance the appearance of different tissue types

bone window setting is commonly used for vertebral column

Question 8

what are the structures shown

Answer 8

1. dorsal spinous process
2. transverse processes
3. vertebral body
4. intervertebral foramen
5. articular facets

Question 9

why is CT useful

Answer 9

for visualizing boney components –> appear white

no superimposition

brain or soft tissue windows can be used to assess the brain and spinal cord

Question 10

what are the structures shown and what scan is this

Answer 10

1. spinal cord
2. intervertebral disc space (nucleus pulposus = a, annulus fibrosus = b)
3. vertebral body
4. dorsal spinous process
5. transverse processes

Question 11

what is seen on T2 weighted imaged

Answer 11

1. CSF appears white or hyperintense
2. intervertebral discs can be distinguished from each other
3. nucleus pulposus is fluid = white or hyperintense
4. annulus fibrosus appears dark or hypointense
5. boney features = dark or hypointense

Question 12

identify the structures

Question 13

what is nuclear scintigraphy

Answer 13

injection of bone seeking agent tagged with radioisotope (gamma emitter)

gamma camera

localization of functional/metabolic changes rather than physical ones

common in equine

Question 14

how is ultrasound useful to view vertebral column

Answer 14

cannot penetrate bone

not used to image vertebral column

examine soft tissue structures

Question 15

what structures are seen on ultrasound

Answer 15

1. vertebral body –> long axis taken from ventrolateral aspect of vertebral column
2. intervertebral disc space –> located between adjacent bodies

very limited for imaging of column and unlikely used