TR effect on Myelin Water Imaging

Myelin water fraction (MWF) is conventionally measured using the T2 decay curve. For a spin-echo based sequence, the repetition time (TR) is limited by SAR. Most MWF studies have been carried out at 3T; but a 1.5T system has lower power deposition, which enables MWF imaging at lower TRs. Shorter TR will also reduce the total scan time. In this work, we performed myelin water imaging on a 1.5T system to investigate the effect of shorter TR on this technique. This work demonstrated increased MWF in human brain in vivo with decreasing TR.