Retrograde cortical and deep venous drainage in patients with intracranial dural arteriovenous fistulas: comparison of MR imaging and angiographic findings

Abstract

Background and purpose: We assessed MR imaging, specifically contrast-enhanced three-dimensional (3D) magnetization-prepared rapid gradient-echo (MP-RAGE), in evaluating retrograde venous drainage in patients with intracranial dural arteriovenous fistulas (dAVFs) that may result in catastrophic venous infarction or hemorrhage.

Methods: Twenty-one patients with angiographically proved dAVFs underwent nonenhanced spin-echo (SE) and fast SE imaging, 3D fast imaging with steady-state precession, and enhanced SE and 3D MP-RAGE imaging. Retrograde venous drainage was categorized as cerebral cortical, deep cerebral, posterior fossa medullary, ophthalmic, or spinal venous. We assessed retrograde venous drainage and graded its severity. MR imaging and angiographic severities were correlated. Sensitivity, specificity, and accuracy were calculated to evaluate the diagnostic utility of each technique compared with conventional angiography. We retrospectively correlated angiograms and MR images.

Results: Enhanced 3D MP-RAGE and T1-weighted SE images had higher diagnostic accuracy higher than nonenhanced images, especially when retrograde drainage involved cerebral cortical, posterior fossa, and spinal veins. Correlation of severity for enhanced MP-RAGE images and enhanced T1-weighted images with angiograms was good to excellent and better than that with nonenhanced images. All sequences had low diagnostic accuracy when drainage was via deep cerebral veins. On retrospective review, 3D MP-RAGE images showed two thrombotic inferior petrosal sinuses.

Conclusion: Enhanced MR images were superior to nonenhanced images in assessing retrograde venous drainage in intracranial dAVFs. Enhanced 3D MP-RAGE is superior to enhanced T1-weighted SE imaging for determining the route and severity of venous reflux because of its increased spatial resolution and ability to contiguously delineate the venous system.

Fig 1.

Case 19. A 78-year-old woman with dAVF in the left CS. A, Lateral intra-arterial DSA of the left ECA shows the arteriovenous shunt in the left CS (long arrow) and retrograde venous drainage to the superior ophthalmic vein (short arrow) and cerebral cortical veins (arrowheads). Severity of the drainage was grade 2 (26%–50% of cortical veins on angiography). B, Axial T2-weighted SE MR image shows flow voids (arrows) in the subarachnoid space, suggesting dilated cortical veins in bilateral frontal and parietal lobes. C, Abnormal dilated cortical veins (arrows) are more prominent on this axial enhanced T1-weighted SE image than in B.

Fig 2.

Case 13. A 70-year-old woman with dAVF in the left CS. Enhanced 3D MP-RAGE image clearly shows marked dilatation and thrombus in the anterior part of the left superior ophthalmic vein (arrows).

Fig 3.

Case 17. A 50-year-old woman with dAVF in the left transverse sinus. A, Lateral intra-arterial DSA of the left ECA shows obstruction of the left transverse sinus (arrows). Abnormal vessels (arrowheads) are observed around the obstructed left transverse sinus. Severity of the drainage was grade 2 (26%–50% of cortical veins on angiography). B, Enhanced 3D MP-RAGE image shows abnormal dilated veins at the base of the cerebrum (arrow) and in the posterior fossa (arrowhead). Bilateral posterior cerebral arteries were identified on other sections (not shown).

Fig 4.

Case 4. A 62-year-old woman with dAVF in the left CS. A, Lateral intra-arterial DSA of the left ICA shows retrograde venous drainage to the superior ophthalmic (arrow) and pontomedullary (arrowheads) veins. B, Enhanced 3D MP RAGE image shows cephalocaudal, contiguous enhancing structures (arrow) at the ventral side of midbrain corresponding to retrograde venous drainage to the pontomedullary vein.

Fig 5.

Case 3. A 58-year-old woman with dAVF in the bilateral CSs. Enhanced 3D MP-RAGE image (and 3D FISP image, not shown) depicts a filling defect in the right inferior petrosal sinus (arrow). This finding suggests thrombosis in the right inferior petrosal sinus.