Quantification of myocardial ischemia and infarction with single photon emission computed tomography

Abstract

To evaluate the feasibility of 201Tl single photon emission computed tomography (SPECT) for quantitative detection of myocardial infarction and ischemia, scintigraphic studies were related to angiographic findings. In study A infarct sizes with SPECT were compared with the angiographic infarct sizes of 30 patients. A linear correlation was found for the % infarct of the left ventricular circumference between both methods (r = 0.73; P less than 0.001; mean infarct size 20.7% +/- 10.5% (angio) vs 19.8% +/- 12.9% (SPECT), mean +/- SD). Furthermore, a significant inverse correlation between scintigraphic infarct size and left ventricular ejection fraction (r = -0.87, P less than 0.001) was obtained. In study B exercise/rest 201Tl SPECT was used for quantification of myocardial ischemia. Forty-three patients underwent both stress 201Tl SPECT and biplane exercise left ventriculography. Ischemia was expressed as % defect size of the left ventricular circumference. Sensitivity and specificity for detection of ischemia were 96% and 100% respectively with stress SPECT. Extent of myocardial ischemia correlated significantly with both methods (r = 0.63; SPECT defect = 1.0 angiographic ischemia +2%; P less than 0.001). The regression followed the line of identity and the mean sizes of ischemia were identical (SPECT 12.2 +/- 7.6% vs 14.6 +/- 12.4% ventriculography, mean +/- SD) demonstrating the agreement of both methods. However, there was some intraindividual variance between the scintigraphic and the angiographic study. The sensitivity and specificity in single regions with SPECT were lower compared to the global test results.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial Perfusion and Left Ventricular Function Early after Successful PTCA in 1-Vessel Coronary Artery Disease

“…Since a strong correlation exists between the size of perfusion defects and the reduction of left ventricular function (5,8,12), we additionally investigated left ventricular global and regional function in order to cope for "falsely positive/negative" 201 T1 scans without a functional correlation. This method was also reported to have a high accuracy to detect restenosis early after PTCA (6).…”

“…The data cube was subsequently rotated around the vertical axis for vertical long-axis slicing, and further rotated for short-axis slicing being performed perpendicular to the long axis of the left ventricle. The accuracy of this scintigraphic technique for detection of reversible/irreversible perfusion defects was reported recently (12). All studies were judged by three experienced investigators (consensus decision) without knowledge of the patients diagnosis.…”