P.083 Characterization of an arteriovenous malformation using 7T structural and functional imaging: A case report

Abstract

Background: Cerebral arteriovenous malformations (AVMs) are a type of vascular abnormality characterized by abnormal connections between arteries and veins without the normal interposed capillary bed. The gold standard for diagnosis is digital subtraction angiography (DSA). Functional MRI (fMRI), particularly with the increased sensitivity at ultra-high field (>=7T), may help to further characterize AVMs, but has not been performed in this population. Methods: We present a functional and structural neuroimaging analysis of an AVM at 7T. Resting-state fMRI was analyzed using independent components analysis (ICA) and compared to normal controls. Structural T1-weighted images were obtained at 1.5T and 7T. The patient also underwent DSA. Results: A 44 year-old, right handed man presented with a generalized tonic-clonic seizure. MRI at 1.5T and 7T revealed an AVM located in the pineal region measuring 3.2 cm. Multiple large feeder vessels were identified, and the AVM drained into the vein of Galen, clearly visualized on the 7T images. Functional imaging revealed an altered default mode network and ICA-identified vascular networks corresponding to the AVM. Conclusions: Imaging at 7T clearly delineates AVM structure. Functional connectivity is altered by the AVM. Vessel-specific independent components were identified that may be helpful for AVM characterization.