Fig 1.

CSF venous fistula visualized best on decubitus CTM. Axial prone CTM image (A) and maximum-intensity-projection image of the same level (B) show subtle linear contrast (arrows) lateral to the T11 nerve root. The patient was turned to the left lateral decubitus position and re-scanned 13 minutes later. Axial MIP image (C) from that scan shows increased intravascular contrast with the patient in the decubitus position, suggestive of a CSF venous fistula (arrow). Axial MIP image (D) from a CTM performed after dynamic myelography on a subsequent day with the patient maintained in the decubitus position after contrast injection shows extensive filling of a paraspinal vein distal to the fistula (arrows).