Spatial coefficient of variation of arterial spin labeling MRI for detecting hemodynamic disturbances measured with 15O-gas PET in patients with moyamoya disease.

Abstract

The aim of this study was to investigate whether the spatial coefficient of variation of arterial spin labeling (ASL-CoV) acquired in clinical settings can be used to estimate the hemodynamic disturbances measured with 15O-gas positron emission tomography (PET), especially an increased oxygen extraction fraction (OEF), in patients with moyamoya disease. We evaluated 68 adult patients with moyamoya disease who underwent ASL (postlabeling delay (PLD) = 1525ms and 2525ms) and PET. Regional values were measured using the middle cerebral artery territorial atlas divided into proximal, middle, and distal regions based on the arterial transit time, and correlations of ASL-CoV with cerebral blood flow, cerebral blood volume, mean transit time, and OEF, as well as the relationship between increased OEF and ASL-CoV, were evaluated. Regardless of the choice of region and PLD, ASL-CoV was significantly correlated with PET-measured parameters, including OEF (|ρ|= 0.30-0.80, P < 0.001). Regions with an increased OEF showed a significantly higher ASL-CoV than regions with a nonincreased OEF (P ≤ 0.03) regardless of the choice of region and PLD. The accuracy of identification of an increased OEF was highest when using a PLD of 1525ms and the middle region (area under the curve = 0.750; using a cutoff value of 31.27, sensitivity = 97.4%, specificity = 41.7%, negative predictive value = 92.6%, and positive predictive value = 67.9%). ASL-CoV may help identify patients with increased OEF.