Few researchers have paid attention to the vascular supply and venous outflow in Parkinson’s disease (PD). In this work, we evaluated arterial inflow and venous outflow and looked for the presence of abnormal venous structure. We found that there was a significant correlation of reduced arterial flow with reduced internal jugular vein (IJV) flow. We also found there were a large number of PD patients with no or little flow in the left IJV compared to healthy control group. These results suggest that abnormal flow could be one factor in the development of or progression of PD in some patients.