1. A method of deriving blood flow parameters from a moving three-dimensional (3D) model of a blood vessel, the method comprising: determining a reference vascular cross-sectional plane through a location of a lumen in the moving 3D vessel model at one time within the model; determining a plurality of target vascular cross-sectional planes at multiple times via temporal tracking of the reference plane based on a displacement field; determining a plurality of contours based on an intersection of the target vascular cross-sectional planes with the moving 3D vessel model at multiple times within the model wherein each contour corresponds to a different one of the multiple times; and determining a blood flow parameter of the vessel from intersections of each contour of a given one of the times with a phase contrast magnetic resonance (PC-MRI) image of the blood vessel from the corresponding time.