Evaluating post-treatment residual intracranial arteriovenous shunting: a comparison of arterial spin labeling MRI and digital subtraction angiography.

purposeTo evaluate the efficacy of arterial spin labeling (ASL) MRI in detecting residual arteriovenous (AV) shunting in treated arteriovenous malformations (AVMs) and fistulas (AVFs).

methodsA retrospective institutional review identified 29 patients with DSA-confirmed AV shunt lesions treated via embolization (n = 17), stereotactic radiosurgery (n = 2), surgical resection (n = 8), or combined embolization and surgical resection (n = 4), with corresponding baseline and post-treatment ASL and DSA studies. Two neuroradiologists independently assessed ASL images for residual AV shunting, with inter-rater agreement calculated. Disagreements were jointly reviewed to reach consensus. Sensitivity and specificity for using ASL to detect residual AV shunting were then determined using DSA as the gold standard reference.

resultsSeventeen patients with Spetzler-Martin grades II-V AVMs were included: 76.5% with supratentorial nidus, and 52.9% with prior hemorrhage. Twelve AVF patients were included, including eight dural, one vein of Galen, two perimedullary, and one cavernous-carotid fistula. Inter-rater agreement for presence of residual AV shunting was strong (93.5%, κ = 0.87). Two disagreements involved AVM patients after surgical resection. Sensitivity and specificity of ASL for detecting residual was 94% and 93%, respectively. Within the AVM group, both metrics reached 100%, while for AVFs, they both decreased to 83%, with one false positive and one false negative.

conclusionASL MRI is highly sensitive and specific for detection of residual AV shunting across a wide spectrum of AV shunt pathologies and treatment modalities. ASL can play an important role as a non-invasive adjunct to DSA, potentially reducing the frequency of DSA during the continuum of post-treatment care.