Classic Case

Subdural injection of contrast media is a complication of myelography. CT lumbar myelogram classically shows contrast in the subdural space (arrows). It is important to be aware of its appearance on CT myelography, as it may be misdiagnosed as tethered cord, arachnoiditis, or mass in the spinal canal. Contrast medium in the subdural space can be easily differentiated from contrast in the epidural space, as contrast in the epidural space extends along the extradural nerve roots into the paraspinal tissues.