Imaging myelin in vivo; comparison of the T2 distribution at 1.5T and 3.0T
Kolind S, MacKay A, Maedler B, Li D
University of British Columbia
We investigated the effects of magnetic field strength on in vivo T2-measurements obtained using a multi-echo imaging sequence. Myelin water fraction (MWF) maps agreed well at 1.5T and 3.0T. MWFs were strongly correlated between 1.5T and 3.0T but were higher in gray matter (GM) at 3.0T than at 1.5T. At 3.0T, the signal-to-noise ratio increased significantly, but the fit-to-noise ratio decreased, possibly due to B1 inhomogeneities. On average at 3.0T, the geometric-mean-T2 of the intra/extracellular peak decreased by 33% in white matter (WM) and 37% in GM, and the intra/extracellular peak widened by 61% in WM and 165% in GM.