Clinical feasibility of simultaneous acquisition rest^{99 m}tc/stress²⁰¹tl dual-isotope myocardial perfusion single-photon emission computed tomography with semiconductor camera

Background: The aim of this study was to evaluate the clinical feasibility of simultaneous acquisition of rest^{99 m}Tctetrofosmin/ stress²⁰¹Tl dual-isotope single-photon emission computed tomography with a semiconductor gamma camera. Methods and Results: Ninety-four patients with known or suspected coronary artery disease (CAD) were enrolled in the study. First, patients were injected with 99 mTc-tetrofosmin (296 MBq) for rest imaging, followed by 201Tl (74 MBq) injection during 6 min of vasodilator stress test. Immediately after the stress test, the patients underwent the first electrocardiogram (ECG)-gated simultaneous acquisition including rest and stress perfusion scans. Patients were brought back for the second simultaneous acquisition for the comparison of ECG-gated wall motion between stress and rest scan 30 min later. Coronary angiography was performed in all the patients within 3 months of this protocol. Sensitivity, specificity and accuracy on a per patient basis to detect significant coronary artery stenosis (≥75%) were 88.6%, 79.2% and 86.2%, respectively. Per coronary vessel, sensitivity, specificity and accuracy were as follows: 84.9%, 80.5% and 83% in the left anterior descending coronary artery; 75%, 93.1% and 86.2% in the left circumflex coronary artery; and 74.2%, 85.7% and 81.9% in the right coronary artery. Conclusions: Simultaneous acquisition of rest 99 mTc-tetrofosmin/stress 201Tl dual-isotope protocol had high diagnostic accuracy for significant CAD.