Accuracy of left ventricular function from electrocardiography-gated myocardial perfusion SPECT by MyoMetrix in Chinese

This work was to determine threshold values for accurate measurements of left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) from electrocardiography-gated myocardial perfusion imaging (MPI) in Chinese, and these data were compared with those of echocardiography. A total of 110 patients with definite or suspected coronary artery disease were referred for both gated MPI and echocardiography within 1 week. The EDV, ESV, and EF automatically measured by MyoMetrix and echocardiography were analyzed using Bland Altman plot correlation and paired t test. The results showed that these parameters quantified by MyoMetrix software were correlated, moderately to highly, with those on echocardiography (rho, r >= 0.75, P < 0.01). However, the EF was not significantly conelated, with post-exercise MPI ESV of <15 mL or resting MPI ESV of <20 mL. At or above this ESV value, EF was underestimated by MyoMetrix (t >= 4.60, P < 0.01). In a word, a small ESV was underestimated by MyoMetrix, which could lead to EF overestimation. On the contrary, a normal or large ESV was overestimated by MyoMetrix, which led to EF underestimation.