Application of a two-pool model of water exchange to myelin water fraction in multiple sclerosis spinal cord

Abstract

Myelin water fraction (MWF) quantifies myelin content in the central nervous system. MWF analysis typically assumes there is no water exchange between different water pools in tissue during the measurement. Here we investigate the effect of incorporating a two-pool model of exchange in a study of MWF in multiple sclerosis (MS) spinal cord and compare with results from the original algorithm. Including exchange resulted in higher MWF values and myelin water residence times that were correlated with MWF, but maintained the expected relationship in MWF between MS subtypes and controls.