ackground : The usefullness of myocardial SPECT in diagnosing cornary artery disease,
& assessing the functional significance of the coronary stenosis is confirmed by many
investigators. To determine the superiority of the quantitative analysis method over the
visual analysis method in assessing myocardial SPECT this study was performed.
Methods ; One hunndered & twenty six patients with suspicious coronary artery disease
had both intraveous dipyridamole 99mTc-MIBI SPECT and coronary angiography within an
interval of 5 days. The scintigraphic findings were assessed visually and quantitatively using
two dimensional polar map. The results of visual and quantitative assessments were
compared to the coronary angiographic findings. In 85 patients who showed perfusion defect
on stress scintigraphy, the reversibility of the defect was evaluated by visual analysis.
Results ; For detectionof coronary artery disease, the overall sensitivity of the visual and
quatitative analyses was 91% & 94% respectively (p>0.05). The overall specificity was 76%
by visual and 71% by quantitative analyses (p>0.05). For detection of individual coronary
branch diseases, the quantitative analysis was higher than visual analysis in the sesitivity
(LAD: 89% vs. 92%, RCA:84% vs. 93%, LCx:71% vs. 77%), but the differences were not
statistically significant. The specificites of both visual and quantitative analyses were
similary high (Lad : 79% vs. 70%, RCA : 77% vs. 82%, LCx : 96% vs. 92%), but there were
no singificant differences also. The reversibility of perfusion defect was assessed by visual
analysis. Of the 144 abnormal vascular territories in 85 patients, 49 vascular territories
showed complete redistribution and 30 territories showed partial redistribution. The patients
with angina had significantly hgih percentage of complete redistribution (angina ; 50% vs. MI;
15%, p<0.05).
Conclusion : Our results showed that quantitative analysis of 99mTc-MIBI tomography
may not be more accurate tchnique than visual analysis for detection of coronary artery
disease and for localization of individusal coronary stenoses.
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