Detection of severity of coronary stenosis by technetium-99M-MIBI imaging at rest, a quantitative spect study

ABSTRACT

Our main aim of the study was to evaluate the potential role of resting technetium-99m-MIBI imaging as a detector of degree of severity of coronary stenosis in patients having an episode of acute myocardial infarction six to twelve weeks before. There were 18 patients underwent resting technetium-99m MIBI perfusion imaging. Scintigraphic results obtained in the form of perfusion indices and angiographic results in the form of percentage stenosis. Perfusion index < 0.65 was considered as tested positive and percentage stenosis > 80 percent without the existence of collateral circulation was taken as diseased positive. The sensitivity, specificity, positive predictive value, and a negative predictive value of the overall test is ninety, eighty five, seventy eight, and ninety four percent respectively. In the myocardial segments supplied by severely stenosed coronary arteries, there was significantly higher MIBI uptake in the segments with good collateral circulation as compared with those subtended by a vessel totally occluded with poor collateral circulation [p<0.01]. It is concluded that quantitative analysis of myocardial tomography with technetium99m MIBI at rest can differentiate between myocardial segments supplied by critically stenosed and non-critically stenosed coronary arteries. It also evaluates the existence of collateral circulation