Spinal CSF Leaks: The Neuroradiologist Transforming Care

A ventral dural tear on a dynamic CT myelogram in a 34-year-old woman showing the direct outflow of the contrast medium (open arrow, A and B) within seconds into the ventral epidural space at the T3–T4 level. The contrast medium then flows cranially within the epidural space (solid arrows, A). The underlying cause is a calcified disc at the T3–T4 level (open arrowhead, A and B).

Digital DSM and conebeam CT of a lateral dural tear in a 36-year-old man. DSM with the patient in the right lateral decubitus position in an anterior-posterior projection suggests a small epidural contrast medium egress, which is unchanged in the subsequent single radiograph (white solid arrows, A and B). C, conebeam CT that follows a few minutes later confirms the epidural accumulation of contrast medium in the coronal view (white solid arrows) at the right T12–L1 level. In addition, a cyst-like structure can be seen within the contrast collection, corresponding to an arachnoid layer (dashed black arrow, C) herniating through a lateral dural tear in the axilla of the exiting nerve root sleeve (black arrowhead, C), which was later confirmed by surgery.

CVF on a DSM (A) in a 47-year-old man with a right T5 CVF (arrow) that was treated with Onyx (Medtronic) embolization (B). The pre-embolization brain MRI (C) demonstrates dural enhancement that nearly normalized 1 month after embolization (D).

Benefit of conebeam CT for detection of a right T6 CVF. Select unsubtracted (A) and subtracted (B) images from a right lateral decubitus DSM show faint linear paraspinal venous opacification (A, arrow). The finding is extremely difficult to appreciate on the unsubtracted image and essentially not seen on the subtracted image (B) due to a combination of pulmonary markings and respiratory motion. Axial (C) and coronal (D) MIP images from a conebeam CT performed minutes later during active contrast injection show a clear right T6 CVF involving several lateral branch veins. In cases such as this, conebeam CT serves as an excellent adjunct to DSM.

CVF occlusion with targeted fibrin glue patching. A, Axial right decubitus CTM shows a right T7 CVF with a paravertebral segmental vein (arrows). B, Axial CT treatment image demonstrates injected fibrin glue within the neural foramen and paravertebral space that matches the CVF drainage course, which is an important feature for treatment success. Posttreatment axial right decubitus CTM (C) shows resolution of the CVF. The pretreatment brain MRI (D) demonstrates dural enhancement (arrows) that resolved 1 month after patching (E).

The advantage of high spatial resolution to detect a right T10 CVF on photon-counting CTM. Axial and sagittal 0.2-mm images (A and B) from a right decubitus photon-counting CTM reconstructed using a relatively smoother Br56 kernel, demonstrate a right T10 CVF involving the ventral and dorsal internal epidural venous plexus (A and B, arrows). Axial 0.2-mm images at the same level, reconstructed using both a smoother Br56 kernel (C) and a sharper Qr89 kernel with denoising (D), show involvement of the intervertebral vein that is only evident on the sharper Qr89 kernel. In some cases, maximizing spatial resolution using a sharper kernel with denoising is necessary to appreciate the full extent of venous opacification.