T1rho (T1ρ) MR imaging in Alzheimer’ disease and Parkinson’s disease with and without dementia

摘要

In the current study, we aim to measure T1rho (T1ρ) 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 T1ρ 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 T1ρ MRI on a 1.5-T clinical-scanner. T1ρ 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 T1ρ 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 T1ρ across the groups (p < 0.001) was observed. Both RH and LH T1ρ 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 T1ρ values were significantly increased compared to PD (p = 0.031, p = 0.027) while compared to PDD only the RH T1ρ value was significantly decreased (p = 0.043). Both RH and LH T1ρ values in PD were significantly lower than PDD (p = 0.004, p = 0.032). No significant correlation between the T1ρ and age as well as between T1ρ and MMSE scores was observed. The serial measurement of T1ρ in both AD and PD may provide the nature of disease progression and may contribute to their early diagnosis.