Vasily L. Yarnykh1, James D. Bowen2, Alexey A. Samsonov3, Pavle Repovic2, Angeli Mayadev2, Bart P. Keogh2, Beena Gangadharan2, Hunter R. Underhill1, Kenneth R. Maravilla1, Lily K. Jung Henson2
1Radiology, University of Washington, Seattle, WA, United States; 2Swedish Medical Center, Seattle, WA, United States; 3Radiology, University of Wisconsin, Madison, WI, United States
Macromolecular proton fraction (MPF) is a key parameter determining magnetization transfer in tissues. Recent studies demonstrated close associations between MPF and myelin content in neural tissues. We present the first clinical evaluation of a recently published fast whole-brain MPF mapping method in multiple sclerosis (MS). MPF in both white and gray matter in MS demonstrated highly significant decrease compared to controls and strong correlations with disability. Notably, gray matter MPF showed the strongest correlations with clinical status, thus emphasizing a critical role of gray matter demyelination in MS. This study establishes MPF as a new quantitative imaging biomarker of demyelination.