Quantification of myocardial flow reserve using a gamma camera with solid-state cadmium-zinc-telluride detectors: Relation to angiographic coronary artery disease

Background Previous studies have suggested using gamma cameras with cadmium-zinc-telluride (CZT) detectors to quantify myocardial blood flow (MBF) and flow reserve (MFR). In this study, we aimed to evaluate the feasibility and accuracy of MFR quantification using a CZT camera compared to coronary angiography. Methods Forty-one participants referred for coronary angiography underwent a rest/stress one-day myocardial perfusion imaging protocol using a CZT gamma camera. Rest and stress dynamic phases were followed by acquisition of traditional perfusion images and time-activity curves were generated. Angiographic and perfusion results were compared to MFR. Results Patients with abnormal perfusion presented reduced MFR (2.01 [1.48-2.77] vs. 2.94 [2.38-3.64], P = 0.002), and reduced stress MBF. Patients with high-risk CAD had lower global MFR compared to patients without obstructive disease (1.99 [1.22-2.84] vs. 2.89 [2.22-3.58], P = 0.026). Obstructed vessels showed lower regional MFR when compared to non-obstructed (1.81 [1.19-2.67] vs. 2.75 [2.13-3.42], P < 0.001). A regional MFR of 2.2 provided a sensitivity of 63.2% and specificity of 74.1% to identify an obstructive lesion in the corresponding artery. Conclusion In patients undergoing invasive coronary angiography for the evaluation of CAD, quantifying MBF and MFR in a CZT gamma camera is feasible and reflects underlying disease. In these patients, reduced regional MFR suggests the presence of obstructive lesion(s).