Radiographs and Myelography

Question 1

Any rotation of xrays will make interpretation unreliable; especially of which two key areas?

Answer 1

• Disc space
• Foramen

Question 2

Radiographs of spine can diagnose what? (3)

Answer 2

discospondylitis,
Bone neoplasia
Vertebral abnormalities such as atlanto-axial subluxation and hemivertebrae.

Question 3

At the start of a dx process; if may be difficult to diagnose discospondylitis and neoplasia, why?

Answer 3

radiographic changes are not always visible at the onset or early stages as it depends on how advanced the pathology is.

Question 4

CARE in cases of vertebral abnormalities; why?

Answer 4

It is essential to assess whether an abnormality is likely to be responsible for the clinical signs observed.

Question 5

Why is myelography used? (2)

Answer 5

evaluate if there is a compressive lesion of the spinal cord
identify the exact location of the lesion.

Question 6

What restraint for myelography?

Answer 6

GA

Question 7

What xrays are taken with myelography?

Answer 7

Survey radiographs of the spine. Two to three subsequent radiographic projections (lateral, ventrodorsal and oblique views– when appropriate)

Question 8

Where is contrast injected with myelography?

Answer 8

into the subarachnoid space.

Question 9

Which spaces can contrast be injected with myelography? (3)

Answer 9

Cisterna magna
L5-L6
L6-L7

Question 10

What contrast medium type for myelography?

Answer 10

Non ionic contrast medium

Question 11

What dose is the contrast medium given for myelography?

Answer 11

0.2-0.3mg/kg

Question 12

What happens with myelography if contrast injected too quickly?

Answer 12

Bradycardia

Question 13

Maximum volume of contrast with myelography?

Answer 13

8ml

Question 14

If too higher volume of contrast with myelography is given; what is there a risk of?

Answer 14

post myelography seizures.

Question 15

CSF analysis should be performed before myelography; what condition could then deteriorate if this isnt done?

Answer 15

Inflammatory CNS disease

Question 16

Myelography will affect CSF results for how long after?

Answer 16

7 days

Question 17

What CSF site is appropriate for thoraclumbar lesions?

Answer 17

Lumbar

Question 18

Which CSF site has the least complications?

Answer 18

Lumbar

Question 19

Seizures secondary to injection of contrast are possible and more likely to be seen with which site of contrast injection?

Answer 19

Cisterna magna

Question 20

Rare, but what is the fatal complication of cisternal myelography?

Answer 20

Subarachnoid haemorrhage

Question 21

Can you think of any benefits of myelography over other diagnostic options? (3)

Answer 21

Relatively cheap
readily available test,
rapid evaluation of the entire spine and allowing dynamic studies.

Question 22

Interpretation of the myelogram relies on evaluation of the contrast columns and classification into what localisation (3)

Answer 22

extradural,
intradural-extramedullary,
intramedullary

Question 23

How do Extradural lesions present with myelography?

Answer 23

Deviations of the contrast column.

Question 24

Examples of extradural lesions (4)

Answer 24

IVDD
fractures
Subluxations
Neoplasia

Question 25

A golf tee sign is often seen in?

Answer 25

Intradural-extramedullary lesions

Question 26

Examples of intradural-extramedullary lesions include (3)

Answer 26

arachnoid cysts,
meningiomas
nerve root tumours.

Question 27

In cases where an intramedullary pathology is suspected, the myelogram may be unremarkable or may show?

Answer 27

divergence of the dorsal and ventral contrast column

Question 28

What does divergence of the dorsal and ventral contrast column suggest?

Answer 28

Spinal cord swelling

Question 29

Examples of intramedullary lesions include (3)

Answer 29

glioma
myelitis
ischaemic myelopathy.

Question 30

What can be performed if interpretation of the myelographic study is difficult?

Answer 30

CT-myelography