Valerie C. Anderson1, David P. Lenar1, Joseph F. Quinn2, William J. Woodward3, Jeffrey A. Kaye2, William D. Rooney3
1Neurological Surgery, Oregon Health & Science University, Portland, OR, United States; 2Neurology, Oregon Health & Science University, Portland, OR, United States; 3Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States
Longitudinal water proton (1H2O) relaxation time constants (T1) are strongly associated with macromolecular volume fraction. Here, we report that 1H2O T1 values are increased in the thalamus of subjects with early AD compared to age-matched, cognitively normal controls. Further, we find that the increased 1H2O T1 values in early AD reflect, at least in part, neurodegenerative (macromolecular loss) processes and that contributions to the increased 1H2O T1 values from altered blood water content (via dilation or increased vessel density) are small.