A CT of the spine post myelogram is a specialized study of the spinal region of interest (see previous section) and may be ordered for the more than one region or the whole spine (cervical, thoracic and/or lumbar).
A myelogram is performed first in a separate procedure. This is similar to a lumbar puncture, or spinal tap, where the fluid space around the spinal cord (within the spinal canal) is accessed with local anesthesia and contrast (usually 12cc non-ionic iodinated contrast) is administered. This is done with fluoroscopic (X-ray) guidance. X-ray images of the contrast will be obtained, after which the patient will be taken to the CT scanner for the CT portion of the study.
Delayed scans, usually obtained four to six hours after the procedure, may be indicated.
A CT post myelogram is indicated in post-operative patients to evaluate for:
- Obstruction of CSF flow
- Spinal stenosis
- CSF leaks
Contrast is generally only given during the myelogram portion of the study (see above). IV contrast is generally not needed.
No preparation is required.
- Only one CT contrast study should be scheduled within a 48 hour period.
- BUN and creatinine must be done within 72 hours of the scan.
- Nothing but clear liquid after midnight before the scan.
- NPO four hours prior to exam (no food or drink).
Generally not required, but may be indicated depending on the patient. Anesthesia on these studies always needs to be authorized by a radiologist.