Respiratory Phase Affects the Conspicuity of CSF-Venous Fistulas in Spontaneous Intracranial Hypotension

Abstract

Spinal CSF-venous fistulas are a cause of spontaneous intracranial hypotension that can be difficult to detect on imaging. We describe how the respiratory phase affects the visibility of CSF-venous fistulas during myelography.

FIG 1.

Maximum-intensity-projection CT myelograms of a right T9 nerve root sleeve CSF–venous fistula. A, Image acquisition during inspiration. Marked increased conspicuity of the CSF–venous fistula and hyperdense paraspinal vein (arrows). B, Image during expiration. The CSF–venous fistula is no longer visible.

FIG 2.

Spot-magnified radiographs of a left T2 nerve root sleeve CSF–venous fistula during an ipsilateral decubitus dynamic myelogram. A, Image acquired during inspiration demonstrates well the contrast-opacified CSF–venous fistula (arrows). B, Image during a Valsalva maneuver results in considerably reduced visualization of the CSF–venous fistula.

FIG 3.

Parasagittal maximum-intensity-projection CT myelograms through the neuroforamen of a left T10 CSF–venous fistula. A, Image acquired during inspiration clearly captures contrast within the CSF–venous fistula (arrowhead). B, Image acquired during expiration. Note the markedly reduced conspicuity of the CSF–venous fistula (arrowhead).

FIG 4.

Spot-magnified radiographs of a left C8 CSF–venous fistula during an ipsilateral decubitus dynamic myelogram. A, Image acquired during inspiration demonstrates increased visibility and extent of the CSF–venous fistula (arrows). B, Image acquired during expiration leads to reduced visibility and extent of the CSF–venous fistula.

FIG 5.

Spot-magnified radiographs of a left T8 CSF–venous fistula during an ipsilateral decubitus dynamic myelogram. A, Image acquired during inspiration demonstrates contrast opacification of the CSF–venous fistula extending out over the transverse process (arrows). B, Image acquired during quiet breath-hold during the mid-respiratory cycle. The CSF–venous fistula is no longer visible over the transverse process.