Metrizamide lumbar epidurography with Seldinger Technique through the sacral notch and selective nerve root injection.

Lumbar epidurography serves as an important radiographic procedure in the evaluation of patients with equivocal myelography and confusing or non-diagnostic physical findings. It is particularly valuable in patients with a wide ventral epidural space secondary to previous surgery, arachnoiditis or on a congenital basis. Several techniques and various contrast agents have been employed for the procedure. A pure Seldinger technique with a caudal approach through the sacral hiatus and injection of metrizamide gives excellent visualization of the epidural space and nerve root sleeves. The proper concentration of metrizamide is crucial for optimal results. Lateral, AP, and AP oblique radiographs, occasionally combined with lateral, complex motion tomography, clearly demonstrate the root sleeves and ventral epidural space. CT scanning, with present technology, does not provide the necessary detail for evaluating the epidural space.