Imaging of spine Flashcards
When should imaging be employed when patients present with back pain?
Most back pain patients don’t require imaging
Need to select patients that have potential for serious instability or neurological damage
When is plain film useful for spinal imaging?
Alignment
Fractures
When is MRI useful for spinal imaging?
Looking at soft tissue structures
When is CT useful for spinal imaging?
Fractures
Discs
Describe the curvatures of the spine?
Cervical and lumbar: lordosis
Thoracic and sacral: kyphosis
Describe the orientation of the facets in the lumbar spine?
Oblique
Describe the shape of vertebral bodies in the lumbar spine?
Concavity in lateral, anterior and posterior margins
Describe what is seen when viewing an X-ray of the anterior lumbar spine?
Thicker cortical bone
Concavity of body
Ring of shadows of cortex of pedicle
Spinal canal between pedicles
Describe why two lines of cortical bine are sometimes seen in imaging of the spine?
When cortical margin in oblique to X-ray beam
Describe what can be seen in an X-ray image of the lateral spine?
Thick and broad spinous process
Thicker cortical bone
Describe what can be seen in an oblique X-ray of the spine?
Scotty dog appearance
Where is a common fracture site of the spine in young people?
How does it appear on imaging?
Lamina - stress fractures
Neck of Scotty dog
Label the features of these X-rays?
How can intervertebral discs be visualised?
CT (T2 weighted)
MRI
Describe the appearance of the intervertebral discs in a T2 weighted C2 image?
Centre of discs appeasr bright
Strong signal due to water content of nucleus
Describe the arrangement of structures exiting the IV foramen?
Nerves superiorly
Small artery
Small nerve
Veins inferiorly
Surrounded by epidural fat
Describe the way in which spinal nerves exit the spinal cord?
Cervical: nerve goes out above pedicle of same name
C8 below C7 and above T1
Rest beneath pedicle
Which level has this axial image been taken at?
Below L1/L2 (cauda equina visible)
Which spinal nerve is affected due to lateral protusion of L4/5 disc? Why?
Which spinal nerve is affected due to lateral protusion of L5/S1 disc? Why?
L4/5: Affects L5 spinal nerve, as L4 nerve root has already exited above
L5/S1: affects S1 spinal nerve, as L5 nerve root has already exited above
Between which structures does the ligamentum flavum run?
Between laminae
Locate the ALL, PLL and ligamentum flavum in the following images?
Which ligaments are visible in axial spinal images?
Don’t see ALL and PLL well
Can see ligamentum flavum
Why is MRI used for spinal imaging?
Discs
Spinal cord
Contents of canal
Nerve roots
How are the spinous processes of the thoracic spine different to that of the lumbar spine?
Longer and more inferior direction
Why is imaging of the thoracic spine more difficult than the lumbar spine?
Don’t see detail as well due to overlying structures
What is visible in imaging of the thoracic spine?
Outline of vertebral bodies
Run down through pedicles
Spinous processes
What is wrong with this image?
Increased kyphosis (due to softening of end plates)
Describe this image?
Osteophytes in the elderly spine
Describe what is wrong with this image?
Disc protrusion
Can disc protrusions be visualised with CT?
Yes
Identify the labelled structures in this image?
Spinal nerves exiting
Describe the abnormality in this image?
Alignment abnormality
Spondylolisthesis
L4 slipped forward on L5
What is bone scintigraphy?
What is it used for?
Injected technetium emits gamma rays > counted by scanner
Technetium taken up by osteoblasts
Assesses vascularity and osteoblastic activity (increased at fracture sites)
