Background and purpose <p>Intracranial dural arteriovenous fistulas (DAVFs) sometimes cause impaired cerebral venous drainage (ICVD), leading to severe neurological outcomes. While digital subtraction angiography (DSA) is the diagnostic gold standard, the assessment of ICVD through the “pseudophlebitic pattern (PPP)” can be subjective and difficult. This study aimed to evaluate the utility of the flow-sensitive black-blood (FSBB) MRI sequence for detecting ICVD in DAVF patients by comparing it with findings from cerebral angiography.</p> Materials and methods <p>We retrospectively analyzed 25 patients with DAVFs who underwent both FSBB MRI and DSA. Two radiologists, an experienced neuroradiologist and a radiology resident, independently evaluated the images. ICVD on FSBB was defined as dilated and tortuous venous structures. Interobserver agreement was calculated using the κ statistic.</p> Results <p>FSBB MRI identified signs of ICVD more frequently than DSA revealed PPP for both the neuroradiologist (76% vs. 64%) and the resident (68% vs. 48%). Importantly, interobserver agreement for detecting these findings was higher with FSBB (κ = 0.72) than with angiography (κ = 0.61). FSBB also detected ICVD in cases that were negative for PPP on angiography, suggesting higher sensitivity. Furthermore, of 14 patients who underwent post-treatment imaging, 12 (87.5%) showed improvement in ICVD findings on FSBB, suggesting its utility in monitoring treatment response.</p> Conclusion <p>FSBB MRI is a highly sensitive and reproducible technique for evaluating ICVD in patients with DAVFs.</p>