Possible Association Between Rupture and Intranidal Microhemodynamics in Arteriovenous Malformations: Phase-Contrast Magnetic Resonance Angiography-Based Flow Quantification

Abstract

To examine a potential association between intranidal microhemodynamics and rupture using a phase-contrast magnetic resonance angiography (PCMRA)-based flow quantification technique in arteriovenous malformations (AVMs). We retrospectively collected data on 30 consecutive patients with AVMs (23 unruptured and 7 ruptured). Based on PCMRA data, maximal (Vmax) and mean (Vmean) intranidal velocities were calculated. Logistic regression analysis was performed to assess factors associated with previous AVM rupture. All ruptures occurred within 6 months before PCMRA. The mean nidus volume was 4.7 mL. Eleven patients (37%) had deep draining vein(s), and 6 patients (20%) had a deep-seated nidus. The mean ± standard deviation Vmean and Vmax were 9.6 ± 2.8 cm/second and 66.7 ± 26.2 cm/second, respectively. The logistic regression analyses revealed that higher Vmax (P= 0.075, unit odds ratio [OR]= 1.05, 95% confidence interval [95% CI]= 1.00-1.10) was significantly associated with prior hemorrhage. The receiver-operating curve analyses demonstrated that a Vmean of 10.8 cm/second (area under the curve= 0.671) and Vmax of 90.2 cm/second (area under the curve= 0.764) maximized the Youden Index. A Vmax > 90 cm/second was significantly associated with AVM rupture both in the univariate (P= 0.025, OR= 9.0, 95% CI=1.3-61.1) and multivariate (P= 0.008, OR= 51.7, 95% CI= 2.8-968.3) analyses. Presence of faster velocities in intranidal vessels may suggest aberrant microhemodynamics and thus be associated with AVM rupture. PCMRA-based velocimetry seems to be a promising tool to predict future AVM rupture.