White matter intercompartmental water exchange rates determined from detailed modeling of the myelin sheath.

ABSTRACT:

Purpose

Magnetization exchange (ME) between hydrogen protons of water and large molecules (semisolids [SS]) in lipid bilayers is an important factor in MRI signal generation and can be exploited to study white matter pathology. Current models used to quantify ME in white matter generally consider water to reside in 1 or 2 distinct compartments, ignoring the complexities of the myelin sheath's multicompartment structure of alternating myelin SS and myelin water (MW) layers. Here, we investigated the effect of this by fitting ME data obtained from human brain at 7 T with a multilayer model of myelin.

Methods

A multi-echo acquisition for a T₂ ^* -based separation of MW from other water signals was combined with various preparation pulses to change the (rela

SUBMITTER: van Gelderen P 

PROVIDER: S-EPMC6258332 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature