Salvage CT Myelography: Same-Session Repositioning to Localize Spinal CSF Leaks

Localization of spinal CSF leaks may require multiple myelograms when the initially suspected CSF leak type is not identified. We describe a salvage CT myelography (CTM) technique in which the patient is repositioned during the same myelographic session to evaluate for an alternative CSF leak type. Eleven patients underwent salvage CTM at three institutions. When the initially suspected CSF leak was not identified, the patient was repositioned with the lumbar puncture needle remaining in place, and additional small contrast boluses and targeted CT acquisitions were performed. Salvage CTM identified alternative CSF leak types across several diagnostic scenarios involving ventral, lateral, dorsal/dorsolateral, and sacral dural tears and CSF-venous fistulas. The mean procedural time was 55.9 minutes, mean contrast dose was 12.5 cc, and mean dose-length product was 2180 mGy-cm. Salvage CTM is an adaptive, same-session strategy that may reduce the need for repeat myelographic sessions and additional lumbar punctures while maintaining reasonable procedural times and contrast doses.