Interactive visualization of three-dimensional SPECT cardiac images

Various methods for interactively viewing single photon emission computed tomography (SPECT) images of the myocardium and cardiac blood pool have been developed. Standard clinical protocols are used to acquire and reconstruct myocardial perfusion and gated blood pool projection data. The 3-D images are segmented with a thresholding algorithm prior to surface rendering on a Stellar GS1000 graphics supercomputer. Viewing regions of interest from arbitrary perspectives permits a more comprehensive evaluation of myocardial perfusion and cardiac performance. Voxel visualization along interactively chosen slicing planes through a 3-D image has been implemented on both the Stellar and on a Sun 3/280 equipped with a graphics accelerator. This presentation is superior to surface rendering for viewing low-amplitude features such as the right ventricular myocardium. Volume rendering has been implemented on these two computers, but it is not yet fast enough for real-time interactive viewing. Interactive visualization of 3-D SPECT images illustrates the potential for greater exploitation of these images in evaluating cardiac physiology and pathology