Tomographic myocardial perfusion imaging with technetium-99m teboroxime during adenosine-induced coronary hyperemia: Correlation with thallium-201 imaging

Abstract

Single-photon emission computed tomographic imaging with technetium-99m teboroxime during exercise has been found to be feasible and the results correlate with those obtained with thallium-201. This study examined the feasibility of this technique and compared tomographic imaging with technetium-99m teboroxime during adenosine-induced coronary hyperemia with thallium-201 imaging. With the patient positioned on the imaging table, adenosine was infused at a rate of 140 μg/kg per min for 6 min. At 4 min, 20 to 25 mCi (740 to 925 MBq) of technetium-99m teboroxime was injected intravenously and imaging was started as soon as the infusion was completed with use of a 180 ° anterior arc and 32 stops at 10 s/stop (total imaging time 7.8 min). Rest images were obtained 60 to 90 min later with use of a similar dose of technetium-99m teboroxime. Exercise tomographic thallium images were obtained within 2 weeks of the teboroxime studies.In the 20 patients studied, the teboroxime images were normal in 2 (50%) of 4 normal subjects and abnormal in 15 (94%) of 16 patients with coronary artery diseases 4 of the 15 had a fixed defect and 11 a reversible defect. There was agreement between teboroxime and thallium studies in 16 patients (80%), in 319 (80%) of 400 segments and in 50 (83%) of 69 vascular segments (p < 0.05). In two normal subjects, an apparent fixed defect involving the inferior wall was seen on the teboroxime but not the thallium images and was thought to be due to an attenuation artifact secondary to extracardiac activity in the left lobe of the liver. There were no clinically significant adverse events.Thus, this preliminary report shows that teboroxime tomographic imaging during adenosine infusion is feasible and convenient. This method combines the strengths of both agents: a very short half-life (12 min for teboroxime and 10 s for adenosine), a rapid imaging sequence (immediately after completion of infusion), maximal coronary hyperemia and a short acquisition protocol (7.8 min). This technique should be an acceptable alternative to exercise thallium-201 imaging.