R₂^* (s⁻¹) at t₀ in each ROI (mean ± standard error).

n = number of subjects. Age was divided into quartiles (q) (the classes for controls being 42–49, 50–53, 54–67, 68–76; for PD patients 42–49, 50–59, 60–68, 69–78) and disease duration, Hoehn and Yahr stage and UPDRS III in terciles (t) (the classes for disease duration being 1–3, 4–6, 7–21; for HY 1–1.5, 2, 2.5–4; for UPDRS III 4–7.5, 8–12.5, 13–40). GM = gray matter; GP = Globus Pallidus; SNc = Substantia nigra pars compacta; SNr = Substantia nigra pars reticulata; WM = white matter; rPut = rostral putamen; cPut = caudal putamen. *p<0.05; analysis of variance (ANOVA). Post-hoc multiple comparisons (Tukey test) showed in the three cases that the difference was significant between the three first quartiles and the fourth.