Optimization of quantitative susceptibility mapping for regional estimation of oxygen extraction fraction in the brain

Purpose We sought to determine the degree which oxygen extraction fraction (OEF) estimated using quantitative susceptibility mapping (QSM) depends on two critical acquisition parameters that have a significant impact time: voxel size and final echo time. Methods Four healthy volunteers were imaged range of isotropic sizes times. The 0.7 mm data downsampled at different stages QSM processing by factor 2 (to 1.4 mm), 3 (2.1 or 4 (2.8 mm) each analysis step. OEF was from 11 veins varying diameter. Inter- intra-session repeatability for optimal protocol repeat scanning in 10 participants. Results Final time found no effect OEF. significant, with larger underestimating OEF, depending proximity vein superficial surface brain last step estimating values images had largest dependency size. Inter-session coefficients variation estimates between 5.2% 8.7% are reported, vein. Conclusion times can be minimized reducing but an than 1 is needed accurately estimate most medium/large brain. Such acquisitions achieved under min.