Assessment of myocardial perfusion and coronary blood flow in man can be performed reliably and successfully using thallium-201 imaging. The extent of exercise myocardial perfusion abnormalities reflects the functional significance of coronary artery stenosis. Accordingly, myocardial perfusion imaging is not only useful for the detection of coronary artery disease, but it also provides unique functional information which should be helpful in the management of patients with known coronary artery disease. The unfavorable physical properties of thallium-201 have limited to a certain extent full utilization of the clinical potential of the methodology. Now technetium-99m-labeled myocardial perfusion imaging agents promise to further enhance the clinical usefulness of myocardial perfusion imaging in patients.
Recent advances in interventional cardiology have pointed out substantial limitations of traditional arteriography in assessing coronary artery anatomy and physiology, especially during the dilatation process. Numerous new techniques are currently being developed to allow visualization of luminal and mural processes, parameters of relative and absolute coronary blood flow, regional myocardial perfusion, and regions of risk. It is possible that the analysis of coronary cross-sectional area may be performed in the future using nonangiographic techniques. The legitimate diagnostic demands and widespread use of coronary angioplasty make it likely that the more promising of these techniques will be clinically available in the near future.
