What are the curvatures of the spine?
- Cervical and lumbar lordoses
- Thoracic and sacral kyphoses
What orientation are the facets in the lumbar spine?
What does oblique imaging of the spine allow for?
Visualisation of facet joints
What are the spaces present in the vertebral column?
- Intervertebral foramina
- Spinal canal
Which MRI modality is useful for imaging IV discs?
T2 - signal comes from water in nucleus pulposis
What happens to the spinal cord below L1?
It becomes cauda equina
What exits the IV foramen from superior to inferior?
- Spinal nerves
- Small artery
- Small nerve
What is the IV forament between?
Pedicles (superior and inferior), vertebral body and IV disc anteriorly, spinous process posteriorly.
What do nerves exit below?
Their pedicle, e.g. L2 nerve root exits below L2 pedicle, between L2 and L3 vertebrae.
Will IV disc protrusion compress its spinal nerve?
No, because the spinal nerve exits above the level of the disc - it can affect the actual spinal cord, though.
What will lateral disc protrusion at the L4/L5 IV vertebrae affect?
L5 nerve, not L4.
How do the anterior and posterior longitudinal ligaments appear in MRI?
As black lines running down the front and back of the vertebral body.
Why do we use MRI in the spine?
Because it's useful for looking at the contents of the spinal canal, the discs and the nerve roots.
What are the advantages and disadvantages of MRI in imaging the spine?
- Advantages: can see the spinal canal, cord, IV discs and nerve roots. Doesn't use radiation.
- Disadvantages: bone visualisation is poor.
What is present in the thoracic vertebrae that isn't in other vertebrae?
- Shape and direction of spinous process is different
- Longer and directed more inferiorly
- Superior and inferior articular facets not coronal, allowing rotation
What is the main use of plan film x-rays in the spine today?
What can disc protrusions be diagnosed using?
CT but not on plain films.
What are the disadvantages of CT?
What are the advantages of CT?
- Bone detail
- Can visualise complex and multi-planar images
What is bone scintigraphy?
- Injected technetium emits gamma rays – counted by scanner.
- Technetium taken up by osteoblasts.
What is bone scintigraphy used to assess?
Vascularity and osteoblastic activity
What is bone densitometry?
- Dual energy X-Ray Absorptiometry
- Uses low dose radiation (X-rays) to measure bone mineral density (BMD)
- Compares measured BMD of the femoral neck or lumbar spine with age-matched reference ranges (Z score) or young normals (T score)
What can bone densitometry combined with other clinical information give information on?
Risk of fracture