Differentiation of dural arteriovenous fistula from reflux venous flow on 3D TOF-MR angiography: identifying asymmetric enlargement of external carotid artery branches

Abstract

AIM: To differentiate dural arteriovenous fistula (DAVF) from reflux venous flow (RVF) by assessment of asymmetric enlargement of external carotid artery (ECA) branches on three- dimensional (3D) time-of-flight magnetic resonance angiography (TOF-MRA). MATERIALS AND METHODS: Nineteen patients with DAVF and 27 patients with RVF were included from September 2007 to April 2019. The locations of DAVF were the cavernous (n¼9) and sigmoid-transverse (n¼6) sinuses, and the jugular (n¼3) and sphenoparietal (n¼1) veins. Two radiologists visually assessed asymmetric enlargement of the ascending pharyngeal artery (ASP), middle meningeal artery (MMA), accessory meningeal artery (AMA), artery of the fo- ramen rotundum, and occipital artery. MMA size was also measured quantitatively. RESULTS: More frequent asymmetric enlargement of the ASP and MMA were seen in DAVF than in RVF (17 of 19 versus 3 of 27 for ASP; 16 of 19 versus 1 of 27 for MMA, p<0.01). The AMA, artery of the foramen rotundum, and occipital arteries were not visualised in RVF pa- tients. The ipsilateral MMA size was significantly larger in DAVF than in RVF (2.14 versus 0.64 mm2, p< 0.01). The diagnostic performance of ipsilateral MMA size for DAVF was good, with an area under the receiver operating characteristic curve of 0.89, with a sensitivity of 84.2% and a specificity of 81.5% at a cut-off of 1.08 mm2. CONCLUSIONS: DAVF showed significantly larger ECA branches than RVF on 3D TOF-MRA. Therefore, thorough evaluation of ECA branches could help to differentiate DAVF from RVF