Diagnostic Performance of Combined Supine–Prone Quantitative Myocardial Perfusion SPECT for Detecting Obstructive Coronary Artery Disease: A Patient- and Vessel-Territory-Based Retrospective Study

Objective: To assess and compare the diagnostic performance of supine-only, prone-only, and software-derived combined supine–prone quantitative myocardial perfusion single-photon emission computed tomography (SPECT) for identifying obstructive coronary artery disease in male patients.
Method: This retrospective, single-center diagnostic accuracy study evaluated men who underwent a one-day stress-rest myocardial perfusion SPECT protocol with technetium-99m (Tc-99m) sestamibi, had both supine and prone stress and rest acquisitions, and subsequently underwent invasive coronary angiography within 3 months. Total perfusion deficit (TPD), summed stress score (SSS), summed rest score (SRS), summed difference score (SDS), and vessel-territory measurements were recorded from the supine, prone, and combined datasets. Obstructive coronary artery disease was defined as stenosis of at least 50% in the left main coronary artery or at least 70% in the left anterior descending artery (LAD), left circumflex artery (LCx), or right coronary artery (RCA).
Results: Combined stress TPD demonstrated the greatest patient-level discriminatory ability (area under the curve [AUC], 0.892; 95% confidence interval [CI], 0.846–0.938). The corresponding AUCs for supine and prone stress TPD were 0.798 and 0.868, respectively. The AUC gain for combined versus supine stress TPD was 0.094 (95% CI, 0.048–0.140; P<.001), whereas the gain for combined versus prone stress TPD was 0.024 (95% CI, −0.008 to 0.056; P=.142). For supine stress TPD, the optimal cutoff was 6.20, yielding 77.0% sensitivity, 73.7% specificity, and 74.5% accuracy. For combined stress TPD, the optimal cutoff was 4.10, yielding 88.5% sensitivity, 84.4% specificity, and 85.4% accuracy.
Conclusion: In male patients undergoing a complete stress-rest examination, software-derived combined supine–prone quantitative myocardial perfusion SPECT (MPS) improved specificity and overall diagnostic accuracy compared with supine-only assessment by reducing false-positive findings caused by inferior and inferolateral attenuation. Combined positioning should be viewed as an adjunct to, rather than a substitute for, paired stress-rest assessment and physician visual interpretation.

Keywords: Computer-assisted image processing, coronary artery disease, myocardial perfusion imaging, sensitivity and specificity, single-photon emission computed tomography.