Background: Observer variability of 99Tcm-sestamibi myocardial perfusion imaging (MPI) has rarely been investigated. The aim of our study was to evaluate the interpretive reproducibility with this technique.
Patients: We report on 108 consecutive male patients with stable angina pectoris, investigated before and after percutaneous transluminal angioplasty (PTCA).
Methods: A 2-day rest/stress 99Tcm-sestamibi gated single photon emission computed tomography (SPECT) protocol was used. MPI was interpreted by two independent observers without knowledge of clinical data, using a 20-segment scoring model.
Results: Intra- and interobserver agreement was found to be good to excellent (kappa = 0.71-0.85) with regard to the overall diagnosis as well as the individual vessel diagnosis (kappa = 0.60-0.87). However, agreement was higher for left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) vascular territories than for the right coronary artery (RCA) territory. Moderate to good intraobserver agreement (kappa = 00.54-0.68) and slightly lower interobserver agreement (kappa = 0.52-0.56) was found for segmental score interpretation. When comparing the interpretive reproducibility before and after PTCA intra- and interobserver agreement was better after PTCA, probably reflecting the increase in normal scans after revascularization.
Conclusions: In a group of consecutive male patients with stable angina pectoris interpretive reproducibility (overall and individual vessel diagnosis) was good to excellent. However, segmental scoring reproducibility was moderate to good.