Dural Venous Channels: Hidden in Plain Sight–Reassessment of an Under-Recognized Entity

Variations of venous drainage. A–D, Hypoplastic superior sagittal sinus (white arrows) is associated with prominent diploic veins (black arrows). E–H, C1 lateral mass region stenoses of the jugular system (open arrows) are associated with compensatory prominence of condylar/suboccipital veins (white arrows), draining in large part into the vertebral venous plexus (dashed arrows). This configuration is further modified in nonrecumbent positions.

The variety of dural venous channels. Any part of the dura can be a venous channel, supra- or infratentorial. There is nothing particularly unique about a tentorial sinus except for the increased frequency of dural venous channels there. 1) Dural venous channel (tentorial sinus group) receiving the basal vein; 2) Dural venous channel (tentorial sinus group) receiving the inferior cerebellar vein; 3) Dural venous channel receiving the vein of Labbe; 4) Dural venous channel (falcine sinus group) receiving a parieto-occipital vein; 5) Dural venous channel (parietal) receiving either a medial or lateral parietal vein such as the vein of Trolard; 6) Dural venous channel (venous lake) receiving the Rolandic/Trolard group of veins; 7) Dural venous channel receiving the superficial Sylvian group of veins. Together with the Labbe dural channel (3 above), these drain into the sigmoid sinus.

Typical dural venous channel (white arrows) draining a large vein of Labbe (white arrowheads). A and B, Angiographic images. C and D, Postcontrast T1 axial volumetric source images. E and F, Volume-rendered reconstructions of the above axial T1 post-contrast dataset.

Mirror image of dural venous channels. Right ICA (A and B), left ICA (C and D), and vertebral (E and F) injections. On the right, the posterior temporal (white arrowhead) vein drains into a dural venous channel (white arrow). The inferior temporal veins drain into a separate dural venous channel (dashed arrow). The 2 channels form a common dural channel (open arrow) draining into the proximal transverse sinus. A mirror image appearance is seen on the left. C and D, Corresponding black arrows. E and F, Vertebral injection opacifies the same dural venous channels (white and black arrows), collecting posterior temporal and occipital veins. Also seen are several dural venous channels in the tentorium cerebelli, also known as tentorial sinuses (curved arrows, ballpoint arrow). G and H, Left anterior oblique views of the left ICA injection profile dural venous channels seen in C and D. Notice the flattened appearance and location of channels lateral to parenchymal veins and corresponding indentations on the inner surface of skull due to flow-related remodeling.

Dural venous channel with an associated arachnoid granulation (arrows)—another characteristic of a dural structure.

Vessel wall imaging of dural venous channels in the falx cerebri (white arrowheads), collecting the Trolard group, and lateral tentorium (white arrows), collecting the Labbe group (black arrows).

A, Classic dural fistula with an arteriovenous connection directly involving a dural (sigmoid in this case) sinus. B, Dural fistula with an arteriovenous connection involving a dural venous channel segment of the Labbe (1) and posterior cerebellar (2) veins. Thrombosis or restriction of antegrade outflow (black circles) into a draining sinus results in retrograde congestion of the cortical venous system. These seemingly “direct” fistulas draining exclusively into a cortical vein are proposed to primarily involve a dural venous channel, explaining the seemingly random dural location of these fistulas.