Imaging the Spine

Question 1

myelogram

Answer 1

injecting contrast into the subarachnoid space to localize lesions as:
- extradural
- intradural/extramedullary
- intramedullary/intrinsic

Question 2

extradural lesions

Answer 2

located between the dura and the bone
- displaces BOTH meninges and parenchyma

Question 3

intradural/extramedullary lesions

Answer 3

located within the subarachnoid space
- displaces ONLY parenchyma

Question 4

intramedullary (intrinsic)

Answer 4

located within the brain parenchyma
- forms a bulge within the parenchyma

Question 5

categories of spinal cord disease

Answer 5

1. developmental
2. trauma
3. degenerative
4. vascular
5. inflammatory
6. neoplastic

Question 6

common developmental spinal cord diseases

Answer 6

• spina bifida
• vertebral anomalies
• hypoplastic odontoid process
• cervical spondylomyelopathy
• chiari-like malformation

Question 7

spina bifida

Answer 7

failure of dorsal vertebral ossification center fusion

Question 8

vertebral anomalies

Answer 8

fusion failure/developmental dysfunction of vertebrae
- causes scoliosis, lordosis, kyphosis

Question 9

hypoplastic odontoid process

Answer 9

fusion of C2 and C3 that causes instability in occipito-atlanto-axial joint

underdeveloped dens causes increased space between C1 and C2
- leads to spinal cord compression

Question 10

cervical spondylomyelopathy

Answer 10

Wobblers syndrome; cervical vertebral malformation
- causes spinal instability, canal stenosis, articular facet/ligament/joint capsule remodeling
- leads to IVD protrusion

Question 11

chiari-like malformation

Answer 11

occipital malformation affecting the foramen magnum and caudal fossa

decreased size of occipital bone causes increased size of foramen magnum
- leads to cerebellar herniation through foramen magnum –> secondary syringomyelia

imaging: syrinx

Question 12

syrinx

Answer 12

fluid filled dilation of the central canal along the spinal cord caused by backup of CSF

Question 13

common spinal cord trauma

Answer 13

spinal fracture

radiographs: shortened vertebral body with compression of spinal cord

CT: fragments visible

Question 14

common degenerative spinal cord diseases

Answer 14

disc herniations –> spinal cord compression

radiographs: spinal cord compression visible with myelogram; narrowed disc space with mineralized material

CT: dark disc (should be well hydrated = bright)

Question 15

common vascular spinal cord diseases

Answer 15

infarctive disorders (fibrocartilagenous embolism)

asymmetric intrinsic lesions
T2 hyperintense bulge
non-contrast enhancing (necrotic tissue)

Question 16

fibrocartilagenous embolism

Answer 16

sudden blockage of spinal cord blood supply with disc material

acute onset, non-progressive
focal and well contained

Question 17

common inflammatory spinal cord diseases

Answer 17

discospondylitis (infection of IVDs and adjacent vertebral endplates)

radiographs: lysis of vertebral endplates, narrow disc space

CT: T2 bright disc space, T1 + C contrast enhancing vertebral bodies and surrounding tissues

Question 18

common neoplastic spinal cord diseases

Answer 18

plasma cell tumor
nerve sheath tumor
histiocytic sarcoma

Question 19

plasma cell tumor

Answer 19

extradural tumor arising from bone

CT: mass + mass effect of flattening spinal cord

Question 20

nerve sheath tumor

Answer 20

extramedullary/intradural mass in SAS

arises from nerve roots exiting the spinal cord
CT: T1 + C golf tee sign (contrast enhancement surrounding mass)

Question 21

histiocytic sarcoma

Answer 21

intramedullary mass

CT: contract enhancing bulge within spinal cord