Sources of variability in the measurement of perfusion defect size using commercially available software programs:...

We recently showed that Quantitative Perfusion SPECT (QPS), Emory Cardiac Toolbox (ECTb) and 4-Dimension-Myocardial SPECT (4DM) yielded discordant results in the assessment of perfusion defect size (PDS) in patients with known or suspected coronary artery disease. In this report, we examined the sources of variability in the measurement of PDS using ECTb (Var_ECTb), 4DM (Var_4DM) and QPS (Var_QPS) and found that gender is a source of variability in the assessment of PDS. In 120 patients, Var_ECTb was lower in men, compared with women, whereas Var_4DM and Var_QPS were similar between both genders. Among men, Var_ECTb was lowest, compared with Var_QPS and Var_4DM, whereas, Var_ECTb, Var_QPS, and Var_4DM were not different among women. Future studies should account for gender differences when comparing the 3 software programs.