Table 2. Correlations between CRs of the SNpc on NM-MRI and SUVRs of the striatum on ¹⁸F-FP-CIT PET on the clinically more affected side.

		Anterior putamen	Posterior putamen	Anterior caudate nucleus	Posterior caudate nucleus	Ventral striatum
More-affected N1
	Correlation	0.319	0.464	0.057	0.029	0.024
	Significance	0.027*	0.001*	0.701	0.843	0.869
More-affected N2
	Correlation	0.078	0.178	0.121	-0.046	0.141
	Significance	0.599	0.225	0.412	0.755	0.341
More-affected combined N1 and N2
	Correlation	0.458	0.324	0.065	0.025	0.031
	Significance	0.001*	0.024*	0.663	0.869	0.834
More-affected whole SNpc
	Correlation	0.304	0.332	0.162	0.059	0.134
	Significance	0.036*	0.021*	0.272	0.690	0.363

^*p<0.05, statistical significance.

CR, contrast ratio; NM-MRI, neuromelanin-sensitive magnetic resonance imaging; N1, nigrosome 1; N2, nigrosome 2; SNpc, substantia nigra pars compacta; SUVR, standardized uptake value ratio; ¹⁸F-FP-CIT PET, N-3-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane positron-emission tomography.