Evaluation of ischemic heart disease by computerized transmission tomography.

As the technology of CTT advances in speed and resolution, a new clinical applications of this modality for noninvasive evaluation of ischemic heart disease should emerge. This modality has already advanced to the stage at which it can compete with echocardiography in producing static images of cardiac structures. The ability of CTT to quantitate regional blood flow using dynamic densitometry is a unique capability of this modality. Although cardiac scintigraphy provides excellent density sensitivity using small amounts of radioactive tracers, it currently lacks the spatial fidelity needed to differentiate many anatomic structures in the heart. Thus, CTT will likely complement the capabilities of other noninvasive imaging modalities. In the future, ultra high-speed CTT scanners will be developed that should provide a multi-section capacity for true three-dimensional imaging. Such scanners will enable many of the cardiac CTT techniques described in this article to advance from the experimental laboratory stage into the mainstream of clinical practice.