Table 1. Correlations between CRs of the SNpc on NM-MRI and SUVRs of the striatum on ¹⁸F-FP-CIT PET on the right and left.

			Anterior putamen	Posterior putamen	Anterior caudate nucleus	Posterior caudate nucleus	Ventral striatum
18F-FP-CIT PET on the right
	N1 right
		Correlation	0.075	0.263	0.075	0.023	0.105
		Significance	0.611	0.071	0.611	0.876	0.477
	N2 right
		Correlation	0.229	0.266	0.067	-0.052	0.063
		Significance	0.118	0.068	0.650	0.726	673
	Flipped left N1
		Correlation	0.220	0.288	0.079	0.015	0.122
		Significance	0.132	0.047*	0.594	0.917	0.408
	Flipped left N2
		Correlation	0.203	0.189	0.124	-0.002	0.136
		Significance	0.166	0.199	0.402	0.992	0.357
	Combined right N1 and N2
		Correlation	0.183	0.257	0.067	0.061	0.099
		Significance	0.213	0.078	0.653	0.680	0.502
	Whole SNpc right
		Significance	0.198	0.150	0.051	-0.037	0.091
		Correlation	0.178	0.308	0.731	0.805	0.539
18F-FP-CIT PET on the left
	N1 left
		Correlation	0.260	0.363	0.186	0.155	0.135
		Significance	0.074	0.011*	0.206	0.294	0.359
	N2 left
		Correlation	0.320	0.300	0.238	0.057	0.240
		Significance	0.027*	0.038*	0.103	0.701	0.101
	Flipped right N1
		Correlation	0.231	0.335	0.177	0.167	0.129
		Significance	0.113	0.020*	0.230	0.256	0.384
	Flipped right N2
		Correlation	0.214	0.230	0.165	-0.011	0.120
		Significance	0.145	0.116	0.261	0.943	0.417
	Combined left N1 and N2
		Correlation	0.270	0.370	0.190	0.142	0.146
		Significance	0.063	0.010	0.195	0.335	0.323
	Whole SNpc left
		Correlation	0.251	0.280	0.188	0.088	0.168
		Significance	0.085	0.054	0.201	0.552	0.254

^*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.