Myocardial Perfusion Imaging in Myocardial Infarction Using 99mTc-MIBI : A New Myocardial Imaging Agent

ABSTRACT

Technetium-99m methoxyisobutylisonitrile(99m-Tc MIBI), a new myocardial imaging agent, was used in myocardial perfusion scan in 23 patients who had been diagnosed as myocardial infarction to assess its usefulness in elvaluation of coronary artery disease. All patients undertook left ventriculography (LVG) and coronary arteriography (CAG). Gated blood pool scan, plannar scintigraphy and SPECT were also done using 99m-Tc MIBI. After then SPECT image was reconstructed to short axis view of the heart at the level of the base, mid and apex. The data from these studies were compared with the results of EKG, LVG and CAG. Diagnostic sensitivity of myocardial scan using 99m-Tc MIBI was 91.3%. In localization of infarction site and evaluation of its extent, myocardial scan was superior to EKG. CAG revealed significant stenosis at the arteries supplying the area in which the scan showed perfusion defect. In detecting abnormal wall motion, the sensitivity and the specificity were 81.9% and 93.7% respectively. Perfusion defect were found in 75%, 82.5%, and 100% of hypokinetic, akinetic, and dyskinetic segments, respectively. Myocardial perfusion scan using 99m-Tc MIBI was an useful noninvasive test in localizing the site and the extent of infarct and detecting the abnormal left ventricular wall motion.