Intra-session repeatability of regional oxygen extraction fraction quantification using asymmetric spin echo MRI

Motivation: Voxel-wise oxygen extraction fraction quantification (OEF) from asymmetric spin echo (ASE) MR data often results in non-physiological values and poor fitting because of inaccuracies in the model relative to voxel composition. Goal(s): To assess the intra-session repeatability of region-wise modeling of ASE MRI data in healthy and sickle cell disease participants. Approach: ASE MR methods were used in 3.0-Tesla MRI to assess the intra-session repeatability of regional OEF quantification. Results: Regions of at least 9 voxels provided moderate-to-excellent repeatability (ICC=0.92-0.95) of OEF quantification from ASE data. Region-wise modeling of intra-session ASE data based on arterial flow territories demonstrated excellent repeatability (ICC=0.87-0.98). Impact: Region-wise modeling of asymmetric spin echo MRI data may provide precise measurement of oxygen extraction fraction, an important hemodynamic measure in cerebrovascular research. Findings from this study suggest potential sensitivity to subtle changes in regional hemo-metabolism with sickle cell disease.