Diagnostic analysis of new quantitative parameters of low-dose dynamic myocardial perfusion imaging with CZT SPECT in the detection of suspected or known coronary artery disease.

The goal of this study is to explore and evaluate the diagnostic values of myocardial blood flow (MBF), myocardial flow reserve (MFR) and relative flow reserve (RFR) obtained with low-dose dynamic CZT SPECT for patients with suspected or known coronary artery disease (CAD). Fifty-seven consecutive patients who underwent low-dose dynamic CZT SPECT and CAG were enrolled. MBF, MFR and RFR were calculated on the vessel level with dedicated quantitative software, and the difference and correlation of each parameter was compared according to the reference standard of stenosis ≥ 50% or ≥ 75% on CAG, respectively. ROC curves were made by stress MBF (sMBF), rest MBF (rMBF), MFR and RFR. The optimal cut-off values and corresponding diagnostic efficacy were obtained and compared with each other. Results indicated that when stenosis ≥ 50% or ≥ 75% on CAG was used as the reference standard at the vessel level, there was no statistically significant difference in rMBF between the negative group and the positive group (P > 0.05), and the sMBF and MFR in positive groups were significantly lower than that in the negative group (all P < 0.05). There was a moderate to significant correlation between sMBF and MFR, sMBF and RFR, MFR and RFR (all P < 0.0001). These results indicate that low-dose dynamic CZT SPECT imaging can easily obtain the sMBF, MFR and RFR, and there is a good correlation among the three parameters, which has a certain diagnostic value for patients with suspected or known CAD, and is a useful supplement to the conventional qualitative or semi-quantitative diagnostic methods.