neuroradiology

Question 1

Disk protrusion terminology

Answer 1

Bulge: Broad-based disk bulge. Usually bulging annulus fibrosus. Protrusion: Focal disk bulge. Usually herniated nucleus pulposus.

Question 2

Intervertebral disk high intensity zone (HIZ)

Answer 2

High T2 signal of annulus indicating annular tear.

Question 3

Disk free fragment mimickers

Answer 3

Conjoined root: Normal variant of two roots exiting thecal sac together. Same density of thecal sac. Tarlov cyst: Normal variant of dilated nerve root sleeve. Same density of thecal sac.

Question 4

Lateral Disks

Answer 4

May cause nerve root impingement causing symptoms of a superior level. Nerve root has already exited central canal.

Question 5

Common causes of Central Canal Stenosis

Answer 5

Facet joint degenerative change (most common). Lligamentum flavum hypertrophy.

Question 6

Most common cause of neuroforaminal stenosis

Answer 6

Facet joint degenerative change with bony encroachment.

Question 7

Lateral recess

Answer 7

Lumbar spine bony canals where nerve roots lie after exiting thecal sac and before entering neuroforamen. Hypertrophy of superior articular facet is most common cause of encroachment.

Question 8

Spondylolysis identified on axial images

Answer 8

Break in bony ring of the lamina (pars interarticularis) at the mid vertebral body level.

Question 9

Spondylolisthesis occurs from either

Answer 9

Bilateral spondylolysis. Facet joint degenerative change.

Question 10

Distinguishes postop scar from disk material

Answer 10

Scar tissue enhances. Disk material has only minimal peripheral enhancement.

Question 11

Differentiates disk infection fromdegenerative disk disease at MR

Answer 11

Type 2 degenerative disk disease: Low T1 disk and high T2 parallel endplate bands. Disk space infection: High T2 disk.

Question 12

Myelopathy neurologic signs

Answer 12

Ataxia. Bowel and bladder incontinence. Babinski sign.

Question 13

Radiculopathy neurologic signs

Answer 13

Muscle weakness. Decreased reflexes. Dermatomal sensory deficits.

Question 14

Urgency for imaging acute myelopathy

Answer 14

Poor prognosis if left untreated for greater than 24 hours.

Question 15

Common causes of myelopathy

Answer 15

Extramedullary: Epidural mass cord compression. Cervical spine stenosis. Intramedullary: Tumor. Inflammation, Arteriovenous malformation (AVM). Spinal dural arteriovenous fistula (SPAVF).

Question 16

Definition of Intramedullary spinal canal lesion

Answer 16

Usually confined to spinal cord. May be exophytic.

Question 17

Definition of extramedullary spinal canal lesion

Answer 17

Outside of spinal cord. May be intradural or extradural.

Question 18

Intradural intramedullary lesions

Answer 18

Ependymoma. Astrocytoma. Hemangioblastoma. Lipoma/(Epi)dermoid. Syringohydromyelia. Intramedullary AVM. Met/abscess (rare).

Question 19

Intradural extramedullary lesions (includes subarachnoid space)

Answer 19

Meningioma. Schwannoma/neurinoma. Neurofibroma. Hemangiopericytoma. Lipoma/(Epi)dermoid. Arachnoid cyst/adhesion. Drop/leptomeningeal metastasis. Veins (extramedullary AVM).

Question 20

Extradural extramedullary lesions

Answer 20

Degenerative: Herniated disc. Synovial cyst. Osteophyte. Rheumatoid pannus. Nondegenerative: Metastasis. Abscess. Hematoma. Primary tumor expansion or invasion. Epidural lipomatosis