Automated quantification of regional myocardial perfusion by analysis of contrast-enhanced echocardiographic images

Quantitative analysis of myocardial perfusion images is currently done by manual techniques. We hypothesized that the seeded region growing procedure, applied to power modulation images, would allow the frame-by-frame detection of myocardial contours, thus eliminating the need for image realignment. We tested this approach in 13 anaesthetized pigs during continuous IV infusion of Definity (DuPont) at baseline, during LAD occlusion and reperfusion. Regional mean pixel intensity was calculated for each consecutive end-systolic frame, and fitted with y=A·(1-e^-β-1). Perfusion defects caused by LAD occlusion were confirmed by a 44±27% decrease in A and a 42±25% decrease in A·β(p<0.05) in the LAD territory, while no changes were observed in non-ischemic segments. With reperfusion, A, β and A·β increased above baseline levels (p<0.05). This technique allows automated quantification of regional myocardial perfusion, without the need for manual tracing and realignment of regions of interest.