Fig. 1: Comparison of quantitative susceptibility mapping and paramagnetic susceptibility mapping among the three groups via whole-brain analysis.

The results were visualized in the MNI coordinate system. a comparison of QSM. b. comparison of χ_para. Warm colors indicate regions where the susceptibility values of the PD-RBD⁺ group are greater than those of the PD-RBD^- group, as well as regions where the susceptibility values of the PD-RBD⁺ group and PD-RBD^- group are greater than those of the HC group. The cool colors indicate the opposite. QSM quantitative susceptibility mapping, χ_para paramagnetic susceptibility mapping, PD-RBD⁺ Parkinson’s disease with secondary rapid eye movement sleep behavior disorder, PD-RBD^- Parkinson’s disease without rapid eye movement sleep behavior disorder.