Real-Time Three-Dimensional Echocardiography of the Left Ventricle-Pediatric Percentiles and Head-to-Head Comparison of Different Contour-Finding Algorithms: A Multicenter Study

Background: Real-time three-dimensional echocardiography (RT3DE) is a promising method for accurate assessment of left ventricular (LV) volumes and function, however, pediatric reference values are scarce. The aim of the study was to establish pediatric percentiles in a large population and to compare the inherent influence of different evaluation software on the resulting measurements. Methods: In a multicenter prospective-design study, 497 healthy children (ages 1 day to 219 months) underwent RT3DE imaging of the LV (ie33, Philips, Andover, MA). Volume analysis was performed using QLab 9.0 (Philips) and TomTec 4DLV2.7 (vendor-independent; testing high (TomTec(75)) and low (TomTec(30)) contour-finding activity). Reference percentiles were computed using Cole's LMS method. In 22 subjects, cardiovascular magnetic resonance imaging (CMR) was used as the reference. Results: A total of 370/497 (74.4%) of the subjects provided adequate data sets. LV volumes had a significant association with age, body size, and gender; therefore, sex-specific percentiles were indexed to body surface area. Intra-and interobserver variability for both workstations was good (relative bias +/- SD for end-diastolic volume [EDV] in %: intraobserver: QLab = -0.8 +/- 2.4; TomTec(30) = -0.7 +/- 7.2; TomTec(75) = -1.9 +/- 6.7; interobserver: QLab = 2.4 6 7.5; TomTec(30) = 1.2 +/- 5.1; TomTec(75) = 1.3 +/- 4.5). Intervendor agreement between QLab and TomTec(30) showed larger bias and wider limits of agreement (bias: QLab vs TomTec30: end-systolic volume [ESV] = 0.8% +/- 23.6%; EDV = -2.2% +/- 17.0%) with notable individual differences in small children. QLab and TomTec underestimated CMR values, with the highest agreement between CMR and QLab. Conclusions: RT3DE allows reproducible noninvasive assessment of LV volumes and function. However, intertechnique variability is relevant. Therefore, our software-specific percentiles, based on a large pediatric population, serve as a reference for both commonly used quantification programs.