COMPARISON OF TECHNETIUM-99M-Q3 AND TL-201 FOR DETECTION OF CORONARY-ARTERY DISEASE IN HUMANS

Technetium-99m-Q3 is a myocardial imaging agent that produces prompt m yocardial visualization in humans. Methods: In 19 patients with angiog raphic coronary artery disease, 2 patients with no angiographic corona ry artery stenosis greater than 50% of the luminal diameter and 6 heal thy volunteers, exercise and resting myocardial imaging were performed with Tc-99m-Q3 and also with (TI)-T-201. Technetium-99m-Q3 imaging be gan 15 min after injection at rest and with exercise, in a complete im aging sequence that required less than 100 min. Results: Overall accur acy for coronary disease detection was 78% (21 true-positive or true-n egative studies among 27 study participants) by tomographic thallium i maging versus 89% for Tc-99m-Q3 tomographic imaging (p = ns). Accuracy for detection of individual coronary stenoses was 75% (61 true-positi ve or true-negative coronary segment classifications among 81 total co ronary segments) for (TI)-T-201 imaging and 83% for Tc-99m-Q3 imaging (p = ns). Conclusions: Technetium-99m-Q3 when used in a rest-exercise sequence that can be completed in 100 min appears to provide comparabl e diagnostic accuracy to (TI)-T-201 for overall coronary disease detec tion and detection of individual coronary artery stenoses.