Imaging of the Spine

Question 1

Why is the clinical history and examination important in imaging?

Answer 1

Decide which imaging is best

Urgency

Question 2

What are plain films used for in the spine?

Answer 2

Alignment

Sometimes fractures

Question 3

Why do we use MRI in the spine?

Answer 3

Spinal cord
Nerve roots
CSF
Ischaemia

Question 4

Why are the bodies of lumbar vertebrae larger than the others?

Answer 4

Take more weight

Question 5

What foraminae do cervical vertebrae have that others don’t?

Answer 5

Transverse foraminae

Question 6

What are the costal facets in the thoracic vertebrae for?

Answer 6

Articulation with ribs

Question 7

What can be accessed via the interlaminar space in the lumbar spine?

Answer 7

Spinal cord via needle

Question 8

What are the features of the lumbar vertebral body in an A-P plain film?

Answer 8

Thin cortical bone
Pedicles look like hollow cylinders
Spinal canal in centres

Question 9

When viewed laterally, what is the direction of the x-ray beam to the lumbar vertebral body in an A-P plain film?

Answer 9

Not entirely tangential
Shows as
- Thick superior cortical margin
- Double line at inferior margin

Question 10

What direction is the x-ray beam in an oblique plain film of the spine?

Answer 10

Parallel to facet joint

45 degrees to body

Question 11

What is the pars interarticularis part of?

Answer 11

Lamina

Question 12

What is the importance of the pars interarticularis?

Answer 12

Thinnest and weakest part

Gets stress fractures

Question 13

Which part of the intervertebral disc usually protrudes: anulus fibrosus or nucleus pulposus?

Answer 13

Nucleus pulposus

Question 14

What is the signal of CSF in a T1 MRI?

Answer 14

Dark

Question 15

What is the signal of CSF in a T2 MRI?

Answer 15

Bright

Question 16

Where does the C1 spinal nerve exit?

Answer 16

Above C1 vertebra

Question 17

Where does the C8 spinal nerve exit?

Answer 17

Below C7 vertebra

Question 18

What is bright on both T1 and T2 MRIs?

Answer 18

Fat

Question 19

What are the advantages of using MRI in the spine?

Answer 19

Shows pathology

Question 20

What are the disadvantages of using MRI in the spine?

Answer 20

Time consuming
Expensive
Hard to access

Question 21

What obscures many structures in the thoracic spine?

Answer 21

Ribs

Question 22

Is irregularity in the endplates of the vertebrae normal or abnormal?

Answer 22

Usually normal in younger people

Can be indicator of pathology

Question 23

Why are disc protrusions more common in the lumbar rather than thoracic spine?

Answer 23

Thoracic spine stabilised by ribs

Question 24

What are the normal curves of the cervical, thoracic, and lumbar spines?

Answer 24

Cervical lordosis
Thoracic kyphosis
Lumbar lordosis

Question 25

What is CT useful for in the spine?

Answer 25

Lumbar disc pathology but not as good as MRI
Bone detail
Complex joints
Multi-planar images

Question 26

Why can the L4 vertebra slip on L5?

Answer 26

Arthritis of facet joint

Defect in lamina = stress fracture

Question 27

What is bone scintigraphy?

Answer 27

Injected technetium emits gamma rays > counted by scanner

Question 28

What takes up technetium?

Answer 28

Osteoblasts

Question 29

What does bone scintigraphy assess?

Answer 29

Vascularity

Osteoblastic activity

Question 30

Which areas show increased uptake of technetium in bone scintigraphy?

Answer 30

Pathology
Bladder because excreted in urine
Injection site

Question 31

What is bone densitometry?

Answer 31

Dual energy x-ray absorptiometry
Low dose x-rays to measure bone mineral density
Compares bone mineral density of femoral neck/lumbar spine with age matched reference ranges/young normals
Combined with other clinical info can give risk of fracture