Quantitative analysis of exercise SPECT thallium in the detection of coronary disease

Quantitative analysis of thallium tomograms were compared with coronary arteriography and left ventriculography in 111 patients who had stabilized after presentation with unstable angina. Visual and quantitative analysis of thallium tomograms had similar sensitivity for detecting coronary stenoses ≥50%, ie, 94% and 88%, respectively. The specificity in the 26 patients without significant stenoses was the same, ie, 81%. The sensitivity for correctly predicting the presence of multiple vessel coronary disease was 75% by the visual technique and 81% by the quantitative technique. In addition, specificity for determining the absence of multiple vessel disease was 79% and 77%, respectively. The visual and quantitative techniques demonstrated similar sensitivity for disease of the left anterior descending (84% and 77%) and right coronary (79% and 84%). However, for the left circumflex coronary artery, the sensitivity was significantly improved from 49% to 81% (P < .05) by quantitative analysis. This improvement in sensitivity occurred without a change in specificity, ie, 85% by visual and 81% by quantitative analysis. Similar specificity of 76% and 74% for left anterior descending and the right coronary artery was found by visual technique, as compared to the quantitative technique of 81% and 72%, respectively. Defect size correlated with the extent of angiographic disease, r = .56, P < .001. Quantitative assessment of thallium reversibility agreed with visual assessment in 62% of vascular territories and quantitatively determined nonreversible defects were more likely to be associated with akinetic or dyskinetic wall motion than visual nonreversible defects. We conclude from these data that quantitative analysis of thallium tomograms is highly sensitive and specific for the detection of coronary artery disease and for individual coronary artery stenoses. The defect size by thallium tomographic analysis significantly correlated with the extent of angiographic disease.

Duke Scholars

Author Paul Wayne Armstrong Medicine, Cardiology