Diagnostic performance of the simultaneous acquisition rest ^{99 m}Tc-tetrofosmin/stress²⁰¹Tl dual-isotope protocol with a semiconductor camera: Comparison with the rest-stress ^{99 m}Tc-tetrofosmin protocol

Background: This study compared the diagnostic value of myocardial perfusion imaging (MPI) between the rest-stress^{99 m} Tc-tetrofosmin protocol (Tc/Tc protocol) and simultaneous acquisition rest^{99 m}Tc-tetrofosmin/stress²⁰¹Tl dual-isotope protocol (SDI protocol) with a semiconductor camera. Methods and Results: We retrospectively studied 147 patients who underwent stress MPI using a cadmium-zinc-telluride camera and invasive coronary angiography within a 3-month interval. The Tc/Tc and SDI protocols were used in 59 and 88 patients, respectively. The sensitivity, specificity, and accuracy of the summed difference score in per-patient analysis were 56%, 85%, and 69%, respectively, for the Tc/Tc protocol and 89%, 82%, and 85%, respectively, for the SDI protocol. The area under the receiver operating characteristic curve was significantly better for the SDI than Tc/Tc protocol for the left anterior descending artery (0.836 vs. 0.674; P=0.0380), the left circumflex artery (0.754 vs. 0.599; P=0.0441), and in per-patient analysis (0.875 vs. 0.707; P=0.0135). There was no significant difference in the diagnostic accuracy of the summed stress score for any vessel or in per-patient analysis between the 2 protocols. Conclusions: The SDI protocol had a higher diagnostic accuracy for the detection of coronary ischemia than the Tc/Tc protocol.