Inter-institutional variability in the quantitative evaluation of global and regional left ventricular function using color kinesls

Color Kinesis (CK) is an emerging technique based on acoustic quantification, which uses color-encoding to depict systolic or diastolic endocardial motion. Pixel transitions between blood and myocardial tissue are detected on a frame-by-frame basis and color-encoded in overlays which reflect the magnitude and timing of endocardial motion in a single end-systolic or enddiastolic frame. We have previously shown that segmental analysis of CK images provides clinically relevant and objective information on LV function in terms of multiple quantitative indices of both global and regional endocardial motion. The aim of this study was to determine the reproducibility of these indices when obtained by sonographers from different institutions. Methods. Six normal subjects (age 23±5) were imaged by six sonographers consecutively in one setting. Each sonographer acquired end-systolic and end-diastolic CK images (SONOS-2500, HP) in both the short axis (SAX) and apical 4-chamber (A4C) views. Images were analyzed using custom software to obtain indices of both the magnitude and timing of global and regional LV function (table). For each index, the inter-institutional variability was calculated as standard deviation in percent of the mean of the values obtained by all participants. Results: S.D./Mean (%) SAX A4C systole diastole systole diastole Global indices: Fractional area change 9 ± 8 ± 3 10 ± 4 10 ± 5 Peak election/filling rate 14 ± 5 14 ± 5 11 ± 4 17 ± 7 Mean time of ejection/filling 7 ± 3 13 ± 6 5 ± 2 11 ± 5 Regional indices: Fractional area change 12 ± 3 10 ± 2 16 ± 6 16 ± 5 Mean time of election/filling 7 ± 3 12 ± 6 5 ± 2 11 ± 5 Conclusion. The inter-institutional variability obtained in this study demonstrated that segmental analysis of CK images provides a reproducible method suitable for clinical evaluation of global and regional LV function.