Early marker for Alzheimer's disease: Hippocampus T1rho (T1ρ) estimation

AbstractPurposeTo evaluate the T1rho (T1ρ) MRI relaxation time in hippocampus in the brain of Alzheimer's disease (AD), mild cognitive impairment (MCI), and control, and to determine whether the T1ρ shows any significant difference between these cohorts.Materials and MethodsWith informed consent, AD (n = 49), MCI (n = 48), and age‐matched control (n = 31) underwent T1ρ MRI on a Siemens 1.5T Scanner. T1ρ values were automatically calculated from the left and right hippocampus region using in‐house developed software. Bonferroni post‐hoc multiple comparisons was performed to compare the T1ρ value among the different cohorts.ResultsSignificantly higher T1ρ values were observed both in AD (P = 0.000) and MCI (P = 0.037) cohorts compared to control; also, the T1ρ in AD was significantly high over (P = 0.032) MCI. Hippocampus T1ρ was 13% greater in the AD patients than control, while in MCI it was 7% greater than control. Hippocampus T1ρ in AD patients was 6% greater than MCI.ConclusionHigher hippocampus T1ρ values in the AD patients might be associated with the increased plaques burden. A follow‐up study would help to determine the efficacy of T1ρ values as a predictor of developing AD in the control and MCI individuals. J. Magn. Reson. Imaging 2009;29:1008–1012. © 2009 Wiley‐Liss, Inc.