Particle trace visualization of intracardiac flow using time-resolved 3D phase contrast MRI

The flow patterns in the human heart are complex and difficult to visualize using conventional two-dimensional (2D) modalities, whether they depict a single velocity component (Doppler echocardiography) or all three component s in a few slices (2D phase contrast MRI), To avoid these shortcomings, a t emporally resolved 3D phase contrast technique was used to derive data desc ribing the intracardiac velocity fields in normal volunteers. The MRI data were corrected for phase shifts caused by eddy currents and concomitant gra dient fields, with improvement in the accuracy of subsequent flow visualiza tions. Pathlines describing the blood pathways through the heart were gener ated from the temporally resolved velocity data, starting from user-specifi ed locations and time frames. Flow trajectories were displayed as 3D partic le traces, with simultaneous demonstration of morphologic 2D slices. This t ype of visualization is intuitive and interactive and may extend our unders tanding of dynamic and previously unrecognized patterns of intracardiac flo w. (C) 1999 Wiley-Liss, Inc.