Els Fieremans1, Jens H. Jensen2, 3, Rachael L. Deardorff2, Amanda Allen2, Jane Kwon1, Ali Tabesh2, Maria F. Falangola2, Steven H. Ferris1, Joseph A. Helpern2
1Center for Biomedical Imaging, Radiology, New York University School of Medicine, New York, NY, United States; 2Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; 3Center for Biomedical Imaging, Radiology , New York University School of Medicine, New York, NY, United States
White matter microstructure in patients with mild cognitive impairment (MCI) and in patients with Alzheimers Disease (AD) is characterized and compared to results for age-matched normal controls (NC), by applying tract-based spatial statistics together with recently proposed specific measures of white matter integrity as derived from diffusional kurtosis imaging. The radial extra-axonal diffusivity was most sensitive in discriminating MCI from NC, while the axonal water fraction was most sensitive in discriminating MCI from AD. These results support a hypothesis that demyelination and axonal loss are key neurodegenerative processes describing conversion from NC to MCI and from MCI to AD, respectively.