Comparison of PET-CT and CZT-SPECT on myocardial blood flow and flow reserve measurement: A systematic review and meta-analysis

Background Myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurement is crucial for diagnosing and managing coronary artery disease and microvascular dysfunction. While positron emission tomography (PET) is the gold standard, cadmium zinc telluride (CZT) is more accessible. This systematic review and meta-analysis aim to compare the accuracy, and the systematic bias of MBF and MFR measurement using CZT compared with PET. Methods We conducted a systematic review across multiple databases up to April 2024. The main outcomes were mean difference between MBF and MFR values obtained from PET and CZT, limits of agreement, and diagnostic performance. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool and statistical analysis was conducted using random effects models. Results Eight studies, encompassing 268 patients, met the inclusion criteria. The mean difference for rest and stress myocardial blood flow between PET and CZT was .006 (95% confidence interval [CI]: −.088, .100) and .111 (95% CI: −.418, .195), respectively. The myocardial flow reserve mean difference was .0178 (95% CI: −.492, .135). Bland–Altman meta-analysis demonstrated a bias of .05 mL/min/g (95%CI: −1.08 to 1.24) for rest MBF, .13 mL/min/g for stress MBF (95%CI: −.969 to 1.228), and .03 mL/min/g (95%CI: −.999, 1.006) bias for MFR. The diagnostic performance for detecting significant reductions in MBF and MFR on single-photon emission computed tomography using PET as the gold standard demonstrated sensitivity and specificity of 80.8% and 87.0%, respectively. Conclusions CZT MBF measurements demonstrated good agreement with PET, although they had a slight underestimation. While PET remains the preferred modality due to its superior performance, CZT represents a viable alternative when PET is unavailable. Future research should focus on standardizing CZT protocols.