Measurement of Left Ventricular Dimensions and Ejection Fraction in Neonates by Three-Dimensional Echocardiography: A Comparative Study Between Philips QLAB and TOMTEC Software-Are the Values Interchangeable?

Feasibility of Three-Dimensional Echocardiographic Analysis in Newborns by Novice Observers

Three-dimensional echocardiography (3DE) provides better interobserver agreement than conventional methods. However, more evidence of whether there is good agreement between novice and experienced observers, especially in pediatric 3DE analysis, is required. We conducted 3DE analysis training in novice observers and investigated the agreement when analyzing 3DE images between novice and experienced observers. One experienced and 4 novice observers independently analyzed 60 3DE images obtained from neonates. The left and right ventricular end-diastolic volume (LVEDV and RVEDV), end-systolic volume (LVESV and RVESV), ejection fraction (LVEF and RVEF), left ventricular global longitudinal strain, and global circumferential strain (LVGLS and LVGCS) were calculated. The novices received hands-on instruction in the analysis procedure before the analysis and received further feedback after their first 40 analyses. Agreement between the novices and the experienced observer was evaluated by the intra-class correlation coefficient (ICC) and percentage difference in 3 groups of 20 images each (images 1-20, 21-40, and 41-60). The ICC of LVEDV was > 0.85 from the first 20 images and increased with experience. The ICCs for RVEDV and RVESV were low from the first 20 images but increased linearly, reaching an ICC > 0.9 in 3 of the 4 novice observers in the last 20 images. The range of the percentage difference was small for LVEDV, RVEDV, LVEF, and RVEF. Novices show an experienced level of 3DE analysis capability in LVEDV and RVEDV after analyzing 40 to 60 images. Training of novices is effective for analyzing LVEDV and RVEDV in 3DE images.

Comparing a knowledge-based 3D reconstruction algorithm to TomTec 3D echocardiogram algorithm in measuring left cardiac chamber volumes in the pediatric population

BACKGROUND

Three-dimensional echocardiography (3DE) is an emerging method for volumetric cardiac measurements; however, few vendor-neutral analysis packages exist. Ventripoint Medical System Plus (VMS3.0+) proprietary software utilizes a validated Magnetic resonance imaging (MRI) database of normal ventricular and atrial morphologies to calculate chamber volumes. This study aimed to compare left ventricular (LV) and atrial (LA) volumes obtained using VMS3.0+ to Tomtec echocardiography analysis software.

METHODS

Healthy controls (n = 98) aged 0-18 years were prospectively recruited and 3D DICOM datasets focused on the LV and LA acquired. LV and LA volumes and ejection fractions were measured using TomTec Image Arena 3D LV analysis package and using VMS3.0+. Pearson correlation coefficients, Bland-Altman's plots, and intraclass coefficients (ICC) were calculated, along with analysis time.

RESULTS

There was a very good correlation between Ventripoint Medical System (VMS) and Tomtec LV systolic (r²  = .88, ICC .89 [95% CI .81, .94]), and diastolic (r²  = .88, ICC .90 [95% CI .77, .95]) volumes, and between VMS and Tomtec LA diastolic (r²  = .75, ICC .89 [95% CI .81, .93]) and systolic (r²  = .88, ICC .91 [95% CI .78, .96]) volumes on linear regression models. Natural log transformations eliminated heteroscedasticity, and power transformations provided the best fit. The time (mins) to analyze volumes using VMS were less than using Tomtec (LV VMS 2.3 ± .5, Tomtec 3.3 ± .8, p < .001; LA: VMS 1.9 ± .4, Tomtec 3.4 ± 1.0, p < .001).

CONCLUSIONS

There was a very good correlation between knowledge-based (VMS3.0+) and 3D (Tomtec) algorithms when measuring 3D echocardiography-derived LA and LV volumes in pediatric patients. VMS was slightly faster than Tomtec in analyzing volumetric measurements.