Semi-quantitative evaluation of myocardial perfusion and left ventricular function: comparison between the standard Anger and novel CZT camera

Introduction: Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a well-established technique for the diagnosis and risk stratification of patients with suspected or known coronary artery disease (CAD). Conventional Anger camera systems for SPECT imaging use sodium iodide crystals and parallel-hole collimators. The novel gamma cameras with semiconductor Cadmium-Zinc-Telluride (CZT) detectors directly convert radiation into electric signals, allowing an improvement in terms of image accuracy and acquisition time. Aim: We conducted a retrospective study to compare the ability of CZT camera (D-SPECT) with that of conventional SPECT in detecting myocardial perfusion and functional abnormalities in patients referred for clinical evaluation of suspected or known CAD at our institution using semi-quantitative analysis of myocardial perfusion and function. Methods: We analyzed 517 consecutive patients with suspected or known CAD underwent gated stress MPI for the assessment of myocardial ischemia at our institution. Linear regression was used to evaluate the correlations between SSS, SRS, EDV, ESV, LVEF and TPD, by D-SPECT versus conventional SPECT and differences between the two methods were assessed by Bland-Altman analysis. In patients with angiographic available data, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy for the detection of CAD (≥50% luminal narrowing) were calculated for conventional SPECT and D-SPECT. A p-value of less than 0.05 was considered as statistically significant. Results: In the overall study population, an excellent correlation between SSS, SRS and TPD, measured by conventional SPECT and by D-SPECT was observed (r=0.808, 0.915, 0.892, p< 0.001, respectively). In Bland-Altman analysis, the mean differences in SSS, SRS and TPD (conventional SPECT minus D-SPECT) were 1.3%, 0.55% and 0.54%, respectively. In 478 patients (92%) who successfully completed LV functional analysis with electrocardiogram-gated SPECT, linear regression analysis showed an excellent correlation between EDV, ESV and LVEF (r=0.911, 0.926, 0.820, p