Multimodal Noninvasive Neuroimaging of Skull‐Base Dural Arteriovenous Fistulas: Beyond Digital Subtraction Angiography.

ABSTRACT Background Dural arteriovenous fistulas (DAVFs) are abnormal shunts between dural arteries and veins without an intervening capillary bed, representing approximately 10%–15% of intracranial vascular malformations. Skull‐base DAVFs most frequently arise in the posterior cranial fossa, particularly near the transverse and sigmoid sinuses, where complex venous anatomy and hemodynamic vulnerability contribute to their development. Although many skull‐base DAVFs are idiopathic, they have been associated with dural venous sinus thrombosis, prior trauma, infection, and previous craniotomy, reflecting the multifactorial nature of their pathogenesis. Imaging Findings Digital subtraction angiography (DSA) remains the gold standard for definitive diagnosis, detailed anatomical assessment, and treatment planning. However, because DSA is invasive and not always immediately available, noninvasive imaging modalities—particularly CT and MRI—play a critical role in early detection, characterization, and prognostic stratification. Cross‐sectional imaging can reveal subtle but important clues, including venous sinus asymmetry, cortical venous engorgement, transcalvarial channels, and parenchymal changes related to venous hypertension. Recognition of these findings is essential, as early suspicion can expedite angiographic evaluation, guide management, and reduce morbidity associated with delayed diagnosis. Conclusion This review synthesizes the key CT and MRI features of skull‐base DAVFs, emphasizing imaging markers that aid in classification and risk assessment, including identification of high‐risk findings such as early venous drainage. Normal anatomical variants and common imaging mimics are also discussed to help avoid diagnostic pitfalls. By promoting early, accurate recognition of these imaging features, this article aims to enhance diagnostic confidence, reduce preventable complications, and guide the appropriate selection of patients for definitive evaluation with DSA.