Reproducibility of an automatic quantitation of regional myocardial wall motion and systolic thickening on gated Tc-99m-sestamibi myocardial SPECT

We investigated the reproducibility of an automatic quantitative algorithm for measuring regional myocardial wall motion and systolic thickening. Meth ods: Tc-99m-sestamibi gated myocardial SPECT with dipyridamole stress was p erformed twice consecutively on 31 patients with known or suspected coronar y artery disease, with the patients in the same position for each scan. Wit h AutoQUANT software, segmental wall motion and systolic thickening were qu antified automatically and expressed in millimeters and percentage increase , respectively, for 20 segments. Afterward, the correlation and agreement b etween repeated measurements were investigated, and the influences of wall location, perfusion grade, and partitioning of the myocardium on reproducib ility were evaluated by ANOVA and t testing. Results: High correlations (r = 0.95 for wall motion and 0.88 for systolic thickening) and good agreement s (weighted kappa = 0.81 and 0.71, respectively) were obtained from repeate d measurements on consecutive gated SPECT. Changes in wall location and per fusion grade did not cause significant differences between repeated measure ments (P > 0.05 in ANOVA and t testing), but a change in partitioning did. On Bland-Altman analysis, 2 SDs for repeated wall motion and for systolic t hickening were 2.0 mm and 20%, respectively. Conclusion: The automatic quan titative algorithm for myocardial SPECT provided by AutoQUANT software has good reproducibility under diverse conditions. A change of motion > 2.0 mm or a change of systolic thickening > 20% can be regarded as significant dur ing a follow-up study using this software.