Motion-frozen myocardial perfusion SPECT improves detection of coronary artery disease in obese patients

In this study, we compared the diagnostic performance of the standard SPECT with motion-frozen (MF) myocardial perfusion SPECT (MPS) in obese patients. Methods: A total of 90 consecutive obese patients (body mass index, 30.1-46.8, average, 34.3 6 3.6; age, 63 6 12 y; 30% women) underwent standard supine rest ²⁰¹Tl/stress ^99mTc dual-isotope gated MPS and cardiac catheterization within 3mo. MF images were obtained by nonlinear warping of cardiac phases to the end-diastolic position. Total perfusion deficit (TPD) was obtained for summed (S-TPD) and motion-frozen (MF-TPD) datasets with sex-specific standard and MF normal limits. Results: The area under the receiver-operating-characteristic (ROC) curve for detection of coronary artery disease (CAD) by MF-TPD was significantly larger than that for S-TPD (0.93 ± 0.25 vs. 0.88 ± 0.32, P < 0.05). MF-TPD had higher specificity (77% vs. 55%, P < 0.05) and accuracy (89% vs. 80%, P < 0.05) than did S-TPD. Conclusion: MF processing of MPS improves CAD detection in obese patients.