Myelographie

Myelography is a radiological procedure in which a radiopaque contrast agent is injected into the intrathecal space to outline the spinal cord, nerve roots, and thecal sac on X-ray or CT imaging. Conventional myelography uses fluoroscopy to guide a lumbar puncture and inject contrast, with radiographs taken in multiple positions to delineate the thecal sac. CT myelography performs CT scanning after intrathecal contrast to obtain detailed cross-sectional images of the spine.

Indications for myelography include evaluation of suspected spinal canal stenosis or nerve root compression when MRI is inconclusive or not feasible, assessment before spine surgery, and investigation of intradural or extradural lesions, tumors, or cerebrospinal fluid leaks. It may be employed when detailed canal visualization is required or when other imaging modalities are insufficient.

Risks associated with myelography include post-dural puncture headache, infection such as meningitis, arachnoiditis, or spinal epidural abscess, bleeding, nerve injury, allergic or adverse reactions to iodinated contrast, and radiation exposure (especially with CT). It is relatively contraindicated in patients with raised intracranial pressure, active spinal infection, coagulopathy, or a puncture-site infection, and in those with known contrast allergy.

Alternatives and role in practice: MRI is the primary noninvasive imaging modality for spine pathology, avoiding intrathecal contrast in most cases, though implants or artifacts can limit its use. CT without myelography is another option in select situations. Myelography and CT myelography remain valuable when MRI is unsuitable or when precise visualization of the spinal canal is required.