1. A method for displaying blood flow, comprising: generating a temporal sequence of 2D phase images representing blood flow through a selected anatomical plane using PCMR imaging; creating a temporal sequence of 3D flow images, wherein a 3D flow image is derived from a 2D phase image and includes one or more flow surfaces plotted above or below the anatomical plane at a height corresponding to the phase in the 2D phase image; and, displaying the sequence of 3D flow images serially to form a four-dimensional flow presentation.