T1ρ and T2ρ MRI in the evaluation of Parkinson's disease

Prior work has shown that adiabatic T-1 rho and T-2 rho relaxation time constants may have sensitivity to cellular changes and the presence of iron, respectively, in Parkinson's disease (PD). Further understanding of these magnetic resonance imaging (MRI) methods and how they relate to measures of disease severity and progression in PD is needed. Using T-1 rho and T-2 rho on a 4T MRI scanner, we assessed the substantia nigra (SN) of nine non-demented moderately affected PD and ten gender- and age-matched control participants. When compared to controls, the SN of PD subjects had increased T-1 rho and reduced T-2 rho. We also found a significant correlation between asymmetric motor features and asymmetry based on T-1 rho. This study provides additional validation of T-1 rho and T-2 rho as a means to separate PD from control subjects, and T-1 rho may be a useful marker of asymmetry in PD.