Interpretive reproducibility of sestamibi myocardial perfusion SPECT in

Interpretive reproducibility of sestamibi myocardial perfusion SPECT in a consecutive group of male patients with stable angina pectoris before and after percutaneous transluminal angioplasty A Johansen, AL Gaster, A Veje, T Haghfelt, P Thayssen, PF Høilund-Carlsen Departments of Nuclear Medicine and Cardiology, Odense University Hospital, Denmark Purpose Results To examine the interpretive reproducibility of 99 m. Tc-sestamibi myocardial perfusion imaging (MPI). Intraobserver agreement was good to excellent (k = 0. 74 -0. 85), while interobserver agreement was found to be good (k = 0. 71 -0. 78) with regard to the overall interpretation of MPI. as being normal, reversible or nonreversible. Exact agreement within and between observers was found in 82 -92% of the cases. Materials 108 male patients, mean age 57 years (range 33 -78) with stable angina pectoris, referred consecutively to MPI before and after percutaneous transluminal angioplasty (PTCA). 53 (49%) patients had prior myocardial infarction. Methods A two-day rest/stress 99 m. Tc-sestamibi gated SPECT protocol was used. MPI was interpreted by two independent observers without knowledge of clinical data, using a semiquantitative visual 20 -segment scoring model (figure 1) and kappa statistics with the following gradings of agreement: poor kappa (k) <= 0. 40, moderate k = 0. 41 -0. 60, good k = 0. 61 -0. 80, and excellent k >0. 80. Contact: allan. johansen@dadlnet. dk The observers had a good to excellent intraobserver agreement for all vascular territories. Interobserver agreement was good in LAD and LCX territories, and moderate to good in the RCA territory (figure 2). Moderate to good intraobserver agreement was found for segmental score interpretation (k = 0. 54 -0. 68), but with slightly lower interobserver agreement (k = 0. 520. 56). When comparing the interpretive reproducibility before and after PTCA, agreement was better after PTCA, probably reflecting an increase in normal scans after revascularisation. Conclusion Interpretive reproducibility (overall and individual vessel diagnosis) was good to excellent. However, segmental scoring reproducibility was only moderate to good. Semiquantitative visual analysis is a robust and a reproducible method of interpretation of MPI allowing comparison of results obtained before and after revascularisation. Figure 1 Figure 2 Before PTCA After PTCA