Preoperative and postoperative mapping of cerebrovascular reactivity in moyamoya disease by using blood oxygen level—dependent magnetic resonance imaging

Abstract

Object. The ability to map cerebrovascular reactivity (CVR) at the tissue level in patients with moyamoya disease could have considerable impact on patient management, especially in guiding surgical intervention and assessing the effectiveness of surgical revascularization. This paper introduces a new noninvasive magnetic resonance (MR) imaging—based method to map CVR. Preoperative and postoperative results are reported in three cases to demonstrate the efficacy of this technique in assessing vascular reserve at the microvascular level. Methods. Three patients with angiographically confirmed moyamoya disease were evaluated before and after surgical revascularization. Measurements of CVR were obtained by rapidly manipulating end-tidal PCO2 between hypercapnic and hypocapnic states during MR imaging. The CVR maps were then calculated by comparing the percentage of changes in MR signal with changes in end-tidal PCO2. Presurgical CVR maps showed distinct regions of positive and negative reactivity that correl...