The application of susceptibility-weighted MRI in pre-interventional evaluation of intracranial dural arteriovenous fistulas

Background and purpose Detection and characterization of intracranial dural arteriovenous fistula (DAVF) is important to plan appropriate therapeutic management. The aim of this study was to analyze the utility of susceptibility-weighted MRI (SWI) in the pre-therapeutic assessment of DAVF in comparison with gold standard digital subtraction angiography (DSA). Materials and methods Prospectively, 26 patients with DAVFs underwent a thorough clinical examination and MRI including SWI followed by cerebral DSA. Two observers blinded to the DSA findings evaluated conventional MRI and SWI images and identified the fistulous area (FA), cortical venous reflux (CVR), and cortical venous ectasia (CVE) and compared these observations with the DSA findings documented by a third observer. Results Aggressive clinical symptoms were observed in 31% of patients and benign features were noted in 69% of DAVFs. Conventional MRI could identify the FA in only 27% of patients. SWI accurately located 75% of all the FAs in 23 patients. However, SWI failed to identify DAVFs in three patients. CVR was detected in 89.6% of all aggressive DAVFs. The accuracy of SWI to identify CVE was 100% and the extent and degree correlated with DSA observations. Conclusions SWI is a reliable non-invasive tool for the localization and characterization of DAVFs and is superior to conventional MRI in the evaluation of DAVFs. This sequence can demonstrate underlying cerebral hemodynamic stresses with a high degree of accuracy and provide valuable pre-therapeutic information.