Overview of multimodal MRI of intracranial Dural arteriovenous fistulas

Abstract

Dural arteriovenous fistulas (DAVFs) include a wide range of pathological conditions that are associated with intracranial vessel abnormalities. While some types of DAVFs present with typical neuroimaging characteristics, others share overlapping pathological and neuroimaging features that can hinder accurate differentiation. Hence, misclassification of the various types of DAVFs is common. Thorough knowledge of DAVF imaging findings is essential to avoid such misinterpretations. Traditional digital subtraction angiography (DSA) is considered the gold standard for diagnosing and evaluating DAVFs. However, angiography cannot detect changes in a patient's brain structure. Conventional magnetic resonance imaging (MRI) sequences, including MR angiography (MRA), allow the evaluation of DAVFs without ionizing radiation or invasiveness. Advanced MRI techniques, such as susceptibility-weighted imaging (SWI) and dynamic contrast-enhanced MRA, provide added value to real-time physio-pathological data regarding the hemodynamics of DAVFs. Beyond these techniques, new insights using high-resolution vascular wall MRI are incorporated for the noninvasive evaluation of DAVFs. This article reviews the pathophysiology of DAVFs, focusing on the specifics of MRI findings that facilitate their classification. The role of conventional and advanced MRI sequences for DAVFs was assessed using insights derived from the data provided by structured reports of multimodal MRIs to evaluate DAVFs.