T1rho (T_1ρ) MR imaging in Alzheimer’ disease and Parkinson’s disease with and without dementia

摘要

In the current study, we aim to measure T1rho (T _1ρ) in the hippocampus in the brain of control, Alzheimer’s disease (AD), Parkinson’s disease (PD), and PD patients with dementia (PDD), and to determine efficacy of T _1ρ in differentiating these cohorts. With informed consent, 53 AD patients, 62 PD patients, 11 PDD patients, and 46 age-matched controls underwent a standardized clinical assessment including mini-mental state examination (MMSE) and brain T _1ρ MRI on a 1.5-T clinical-scanner. T_1ρ maps were generated by fitting each pixel’s intensity as a function of the spin-lock pulse duration. In control, AD, PD and PDD, mean ± SE T _1ρ values in the right hippocampus (RH) were 92.15 ± 2.00, 99.65 ± 1.98, 85.68 ± 1.87, 102.47 ± 4.66 ms while in the left hippocampus (LH) these values were 90.16 ± 1.82, 99.53 ± 1.91, 84.33 ± 2.03, 95.33 ± 4.64 ms. Significant difference for both RH and LH T _1ρ across the groups (p < 0.001) was observed. Both RH and LH T _1ρ were significantly increased in AD compared to control (p = 0.034, p = 0.001) and PD (p < 0.001, p < 0.001). In control, both RH and LH T _1ρ values were significantly increased compared to PD (p = 0.031, p = 0.027) while compared to PDD only the RH T _1ρ value was significantly decreased (p = 0.043). Both RH and LH T _1ρ values in PD were significantly lower than PDD (p = 0.004, p = 0.032). No significant correlation between the T _1ρ and age as well as between T _1ρ and MMSE scores was observed. The serial measurement of T_1ρ in both AD and PD may provide the nature of disease progression and may contribute to their early diagnosis.