Fig. 4

A 37-year-old woman with spontaneous intracranial hypotension (case #2). Initial myelography failed due to extensive subdural contrast injection. Axial MDCT-myelography (a) revealed a dense high-attenuated subdural area (white arrow) with dark attenuated dural sac. So, blind epidural blood patch was done in the C7/T1 level, but the symptom did not improve after that. One week later MDCT-myelography was repeated. On axial CT image (b), contrast leakage was seen at the L1 level with “gray-rim sign” (peripheral leaked contrast with white arrow and central dense contrast with black arrow). Targeted epidural blood patch was done at the L1 level; the symptoms of the patient relieved dramatically, and she was discharged the next day