3D Myocardial Perfusion Visualization

The overall goal of this project is to create realistic, quantitative visualization models of three-dimensional distributions of perfusion (flow) in the heart muscle (myocardium). The model is created from information derived from tomographic imagery, single-photon emission computer tomography (SPECT) and positron emission tomography (PET).

Typically, the PET and SPECT information is displayed as two-dimensional (polar or "Bullseye") plots. In these 2D representations, the 3D perfusion distribution is deformed onto a plane, much as the Earth's surface is deformed in a Mercator map projection. Thus, three-dimensional display of SPECT and PET cardiac information are generally held to be superior to polar map or bullseye displays, since they do not distort the spatial position or extent of perfusion information, but instead show the data with more geometric accuracy and realism.

Standard perfusion quantification results detect the location and intensity of maximum pixel values around the LV myocardium. These values generally occur near the center of the myocardium, closer to the endocardial than the epicardial surface. From this information we devised a method to estimate and display the LV epicardial surface at end-diastole. The coordinate system used is displayed on the right. Median and smoothing filters were applied to remove extreme incorrect values and to create a surface better approximating the smoothness of the epicardium. The resulting surface may be useful for evaluating size and shape of the LV, and for aiding in registration of perfusion data with information from other imaging modalities.

Preliminary evidence shows that evaluation of 3D displays of perfusion quantification is also more accurate than qualitative evaluation of the imagery.

Project Members:

• Dr. Norberto F. Ezquerra
• Tracy L. Faber
• C. David Cooke
• John W. Peifer
• Russell D. Folks
• Roderic I. Pettigrew
• John P. Vansant
• John R. Leyendecker
• Dr. Ernest V. Garcia
• L. Klein

References:

• "Three-Dimensional Displays of Left Ventricular Epicardial Surface from Standard Cardiac SPECT Perfusion Quantification Techniques,"
  T. Faber, D. Cooke, J. Peifer, et al. Journal Nuclear Medicine, Vol. 36, No. 4, pp. 697-703, April 1995.

• "PerfSPECTive","
  Software disclosure filed with the Georgia Institute of Technology, Office of Technology Licensing, March 1994.

• "Visualization of Multimodality Cardiac Imagery,"
  J. Peifer, E. Garcia, D. Cooke, L. Klein, R. Folks, and N. Ezquerra. Proc. Vis. in Biomed. Comp. Conf. (VBC '92), pp. 225-233, Chapel Hill, NC, October 1992.