MR imaging of dural arteriovenous fistulas draining into cerebellar cortical veins

Abstract

Background and purpose: Retrograde leptomeningeal venous drainage (RLVD) in a dural arteriovenous fistula (DAVF) is associated with intracerebral hemorrhage, nonhemorrhagic neurologic deficit, or death, and recognizing the presence of this drainage is important. We investigated the MR findings of DAVFs draining into cerebellar cortical veins and compared these findings with those of conventional angiography.

Methods: The MR and angiographic findings of six patients (five men, one woman; mean age, 73.4 years) with DAVF with RLVD into cerebellar cortical veins were reviewed retrospectively. Signal intensity characteristics, contrast material enhancement, topography of the lesion, and presence of signal voids were evaluated on MR images. Site of the shunt, feeding arteries, and draining veins were evaluated on angiograms.

Results: In all patients, MR images showed high signal intensity on T2-weighted images and peripheral enhancement on gadolinium-enhanced T1-weighted images at the inferior aspect of the cerebellar hemisphere. A combination of posterior meningeal and occipital arteries was the most frequent blood supply (83%) for these DAVFs. In all six patients, the inferior hemispheric vein was the primary draining vein.

Conclusion: The characteristic MR findings of DAVF draining into cerebellar cortical veins represent venous congestive encephalopathy in the territory of the involved cortical vein.

Fig 1.

Patient 1, a 73-year-old man who presented with incoordination and ataxia. A, Parasagittal T1-weighted MR image shows a low-signal-intensity lesion involving the posterior inferior aspect of the cerebellar hemisphere. B, Axial T2-weighted MR image shows an ill-defined high-signal-intensity lesion (asterisk) in the left cerebellar hemisphere. Note multiple signal voids in the peripheral portion of the lesion. C, Axial gadolinium-enhanced T1-weighted image demonstrates intense peripheral enhancement of the left hemispheric lesion, with a central nonenhancing area. D, Left external carotid artery angiogram demonstrates DAVF (short thick black arrow) supplied by meningeal artery of cerebellar (Mening. a. of Cbll.) fossa coming from a neuromeningeal branch of the right ascending pharyngeal artery and left occipital artery (Occp. A.) draining through the inferior hemispheric vein (curved arrow).

Fig 2.

A–C, Axial T2-weighted MR images in patient 5 (A), patient 2 (B), and patient 4 (C) show high signal intensity of the lesion, with various degrees of signal voids.

Fig 3.

A–C, Gadolinium enhanced T1-weighted MR images in patient 3 (A, coronal), patient 2 (B, axial), and patient 4 (C, coronal) show diffuse peripheral enhancement.

Fig 4.

A and B, Lateral (A) and anterioposterior (B) selective angiograms of the meningeal artery of the cerebellar (Mening. A. of Cbll.) fossa in patient 3 show a DAVF draining into the inferior vermian vein (Inf. Verm. V.) via a short tentorial sinus (Tent.S.). C, Right vertebral angiogram in patient 4 demonstrates enlarged artery of the falx cerebelli (A.of Falx Cbll.) supplying a DAVF and draining into the right inferior hemispheric vein (Inf.Hemsp. V.) through the tentorial sinus (Tent.S.)