Vertebral Column 4 Flashcards
what are the diagnositc imaging options of the vertebral column
- radiography
- computed tomography (CT)
- magnetic resonance imaging (MRI)
- nuclear scintigraphy
- ultrasound
what are the most radiographic views taken of the vertebral column
- lateral view
- ventrodorsal view
what are the labelled parts
- dorsal spinous process
- transverse processes
- vertebral body
- invertebral foramen
- articular facets
- intervertebral disc space
what are the drawbacks of radiographs
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
what is a myelogram
injection of contrast medium into vertebral canal (subarachnoid space)
outlines spinal cord
where can the constrast medium for myelogram be injected
- cisterna magna –> occipital crest of skull, dorsal spinous process of axis, transverse processes or wings of atlas, needle is introduced midline
- lumbar region –> cranial to dorsal spinous process of L6
what is the bone window
CT image produced can be altered to enhance the appearance of different tissue types
bone window setting is commonly used for vertebral column
what are the structures shown
- dorsal spinous process
- transverse processes
- vertebral body
- intervertebral foramen
- articular facets
why is CT useful
for visualizing boney components –> appear white
no superimposition
brain or soft tissue windows can be used to assess the brain and spinal cord
what are the structures shown and what scan is this
- spinal cord
- intervertebral disc space (nucleus pulposus = a, annulus fibrosus = b)
- vertebral body
- dorsal spinous process
- transverse processes
what is seen on T2 weighted imaged
- CSF appears white or hyperintense
- intervertebral discs can be distinguished from each other
- nucleus pulposus is fluid = white or hyperintense
- annulus fibrosus appears dark or hypointense
- boney features = dark or hypointense
identify the structures
what is nuclear scintigraphy
injection of bone seeking agent tagged with radioisotope (gamma emitter)
gamma camera
localization of functional/metabolic changes rather than physical ones
common in equine
how is ultrasound useful to view vertebral column
cannot penetrate bone
not used to image vertebral column
examine soft tissue structures
what structures are seen on ultrasound
- vertebral body –> long axis taken from ventrolateral aspect of vertebral column
- intervertebral disc space –> located between adjacent bodies
very limited for imaging of column and unlikely used
