Figure 1. The definition of PD patients with motor asymmetry and the intergroup difference of regional tissue susceptibility. (A) The PD patients with significant motor asymmetry defined by using three objective criteria: conservative criterion, slacked criterion and hemiparkinsonism inclusion. (B) The inter-group differences between normal controls and PD patients with significant motor asymmetry that were defined by the three criteria mentioned above. */** are relating to the intergroup difference of regional tissue susceptibility. † is relating to the hemispherical difference (dominantly affected nucleus vs. non-dominantly affected nucleus) of regional tissue susceptibility. *: p < 0.05; **: p < 0.005 with Bonferroni correction. †: p < 0.05; ††: p < 0.01 with Bonferroni correction. PD = Parkinson’s disease; SN = Substantia nigra; PUT = Putamen; GP = Globus pallidus; CN = Caudate nucleus; RN = Red nucleus. DSN = Dominantly affected SN; NDSN = Non-dominantly affected SN; DPUT = Dominantly affected putamen; NDPUT = Non-dominantly affected putamen; DGP = Dominantly affected GP; NDGP = Non-dominantly affected GP; DCN = Dominantly affected CN; NDCN = Non-dominantly affected CN; DRN = Dominantly affected RN; NDRN = Non-dominantly affected RN; SD = Standard deviation.