Analysis of flow patterns using MRI

This paper describes new software programs for analysis and visualization o f blood flow patterns derived from time-resolved 3D velocity data sets. Usi ng the programs, data can be displayed in cross-sectional or 3D perspective view. Particle paths revealing the flow patterns are computed by forward a nd backward time integration of the velocity field. Vector arrowmaps are co mputed as short-duration paths starting from uniformly spaced points over t he lumen volume. Background, divergence, and local boundary correction is d one to improve the realism of the paths. The programs have been used to vis ualize flow patterns from non-gated and cardiac-gated 3D velocity enclosed data in over 35 subjects. Arrowmaps are preferred for revealing local regio ns of different blood flow characteristics within the vessel, while particl e paths are preferred for revealing global organization of the flow. They a re complementary display strategies. Advanced data handling and display fea tures are essential for analyzing and visualizing large velocity encoded da ta sets.