Monitoring demyelination and remyelination by magnetization transfer imaging in the mouse brain at 9.4 T

Objective The aim of this study was to assess quantitatively structural changes in myelin content occurring during demyelination and remyelination by magnetization transfer imaging (MTI). Materials and methods In a reversible model of demyelination with no axonal loss, mice intoxicated by cuprizone were studied by MTI in vivo at 9.4 T. MRI data were compared to histopathological examinations. Results Data revealed that the magnetization transfer ratio (MTR) decreased significantly during demyelination and increased during remyelination with strong correlation to the myelin content (r = 0.79, P = 0.01). Conclusions This study demonstrated that MTR is a sensitive and reproducible quantitative marker to assess myelin loss and repair. This may lead to in vivo monitoring of therapeutic strategies promoting remyelination.