Susceptibility-Based Characterization of Cerebral Arteriovenous Malformations

OBJECTIVES: The aim of this study was to explore blood deoxygenation across cerebral arteriovenous malformations (AVMs) for functional characterization of AVM vasculature. MATERIALS AND METHODS: Fifteen patients with cerebral arteriovenous vascular malformation were prospectively studied by digital subtraction angiography and using a 3 T magnetic resonance imaging system, with which three-dimensional (3D) gradient echo data for the calculation of quantitative susceptibility maps, velocity-encoded 3D gradient echo data for 3D flow assessment, and contrast-enhanced 3D time-of-flight data were acquired.The nidus, major supplying artery, and major draining veins were identified on digital subtraction angiography, and volumes of interest of the AVM nidus, AVM-related inflow and outflow vessels, and non-AVM-related normal veins were drawn on coregistered contrast-enhanced 3D time-of-flight data. The resulting volumes of interest were applied to quantitative susceptibility mapping and flow data. RESULTS: All patients showed a significant stepwise increase in susceptibility between feeding artery and nidus as well as between nidus and draining vein (Padjusted = 0.035, Padjusted= 0.007, respectively). Results revealed between 9.3% and 50.9% of the normal transcapillary blood deoxygenation-related susceptibility change between the feeding artery and the draining vein of the AVMs. When normalized by nidal blood flow velocity, this change was correlated with the presence of perinidal blood products. The mean susceptibility change across cerebral AVMs normalized with nidal volume inversely correlated with mean nidal flow velocity. CONCLUSIONS: Susceptibility changes indicating blood deoxygenation across cerebral AVMs were shown for the first time in this study and were associated with the presence of perinidal blood products. Deoxygenation measures may serve as functional characterization of AVM vasculature and may offer the potential for individual treatment assessment and possible risk stratification.