Resting-state functional MRI (fMRI) and diffusion MRI (dMRI) have been widely exploited in studies of Parkinson's disease (PD) in the attempt to identify early diagnostic biomarkers of PD and to describe neural correlates of both motor and non-motor symptoms of the disease and their progression. With resting-state fMRI (rs-fMRI), study results remain controversial particularly because of the heterogeneity of PD populations studied, the various analytical methods used, and the impact of distinct brain pathology, neurodegeneration, and dopaminergic medication on the resting-state functional connectivity (rs-FC) strength.