LABORATORY INVESTIGATION NUCLEAR CARDIOLOGY

The use of preintervention and postintervention thallium imaging for assessing the early and late effects of experimental coronary arterial reperfusion in dogs ROBERT D. OKADA, M.D., AND GERALD M. POHOST, M.D. ABSTRACT To determine if thallium-201 imaging of myocardial perfusion can be used as an early predictor of myocardial salvage after reperfusion, 24 adult dogs were subjected to complete occlusion df the left anterior descending coronary artery with release of the snare 2 hr later. Separate doses of thallium (1 mCi) and microspheres were given 15 min before, 5 min after, and 1 hr after release of the snare. Gamma camera images of the heart were obtained after each injection of thallium. Preinjection images were also acquired before the second and third doses and were subtracted from the postinjection images to eliminate the counts due to residual activity from the prior injections. The chest was then closed and the dog allowed to recover. The chest was reopened 48 hr later, final doses of thallium and microspheres were administered, and the heart was imaged. After the dog was killed, the left ventricle was sliced from apex to base, and any infarct was outlined with triphenyltetrazolium (TTC) staining