4D PC-MRI enables the assessment of blood flow velocity vectors of one heart beat. These time-dependent, three-dimensional data allow for a comprehensive analysis and contain plenty of information. So far, 4D PC-MRI is used for research purposes. One reason is a lack of standardized, easy-to-use evaluation software, which is crucial for potential application in clinical routine. In this system’s paper, we present our software Bloodline, a tool combining advanced visual exploration and analysis of 4D PC-MRI data. We will put emphasis on design decisions and requirements that arose from the close collaboration with cardiologists and radiologists. The tool provides a guided data processing and evaluation workflow. The pre-processing pipeline comprises generic data import, artifact correction, vessel segmentation, surface as well as centerline extraction, cardiac cycle definition, and landmark specification. Bloodline integrates advanced visualization techniques and facilitates a dataset evaluation within ten minutes. Qualitative and quantitative flow analysis methods are provided. The focus lies on the detection and characterization of vortices, which are correlated to cardiovascular diseases.