Myelin volume fraction imaging with MRI

Neuroimage. 2018 Nov 15:182:511-521. doi: 10.1016/j.neuroimage.2016.12.067. Epub 2016 Dec 23.

Abstract

MRI is a valuable tool to assess myelin during development and demyelinating disease processes. While multiexponential T2 and quantitative magnetization transfer measures correlate with myelin content, neither provides the total myelin volume fraction. In many cases correlative measures are adequate; but to assess microstructure of myelin, (e.g. calculate the g-ratio using MRI), an accurate measure of myelin volume fraction is imperative. Using a volumetric model of white matter, we relate MRI measures of myelin to absolute measures of myelin volume fraction and compare them to quantitative histology. We assess our approach in control mice along with two models of hypomyelination and one model of hypermyelination and find strong agreement between MRI and histology amongst models. This work investigates the sensitivities of MRI myelin measures to changes in axon geometry and displays promise for estimating g-ratio from MRI.

Keywords: Histology; MRI; Magnetic resonance imaging; Myelin; Tuberous sclerosis; g-ratio.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Demyelinating Diseases / diagnostic imaging*
  • Demyelinating Diseases / pathology
  • Disease Models, Animal
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Imaging / standards
  • Mice
  • Mice, Knockout
  • Models, Theoretical*
  • Myelin Sheath* / metabolism
  • Neuroimaging / methods*
  • Neuroimaging / standards
  • Sensitivity and Specificity
  • White Matter / anatomy & histology*
  • White Matter / diagnostic imaging*
  • White Matter / pathology