Three-dimensional imaging of the myocardium with isotopes

Successful transverse section results were obtained by multiple views of the human thorax using the gamma camera and longitudinal tomographic images of the heart have been obtained by digital reconstruction of multiple pinhole images. However, the time and skill required for these techniques necessitate new instrumentation which will overcome the limitations we have come to understand in the past years. The answer is not in a better resolution camera, but the proper geometry such as the positron ring-detector system being pursued by Washington University, UCLA, Berkeley, and perhaps other groups. It is feasible to obtain transverse sections of 12 portions of the cardiac cycle with 4 mm FWHM with a radiation dose less than 100 mrads. This compares favorably with proposed fast transmission whole-body scanners. The nuclear medicine approach will give not only physiological or topographical function, but perhaps more importantly will provide a measure of in vivo metabolism