Single injection thallium-201 stress and redistribution myocardial perfusion imaging: comparison with stress electrocardiography and coronary arteriography.

The efficacy of single injection thallium-201 exercise stress and rest redistribution imaging in the evaluation of myocardiacl ischemia was compared with stress electrocardiography and coronary arteriography. Thallium-201 imaging was interpreted at two levels of sensitivity in order to define the circumstances under which it best serves as a screening modality for coronary arteriography. With the prevalence of coronary disease usually found in patients referred for coronary arteriography (75%), unprocessed thallium-201 imaging is as good as stress electrocardiography in identifying patients apt to show coronary artery abnormalities, but not much better than stress electrocardiography in delineating those patients unlikely to show coronary artery disease. In contrast, processed lesion enhanced images showing normal results virtually eliminate the possibility of significant arteriographic findings. With this screening technique, many patients may be spared unnecessary coronary arteriography.