T_1ρ and T_2ρ MRI in the evaluation of parkinson's disease

Prior work has shown that adiabatic T_1ρ and T _2ρ 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_1ρ and T_2ρ 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_1ρ and reduced T_2ρ. We also found a significant correlation between asymmetric motor features and asymmetry based on T_1ρ. This study provides additional validation of T_1ρ and T_2ρ as a means to separate PD from control subjects, and T_1ρ may be a useful marker of asymmetry in PD.