Objective We sought to investigate the feasibility and reproducibility of the new semi-automated tool (4DLVQ) quantification of left ventricular (LV) volumes and ejection fraction (EF) compared to standard 3D echo tool (TomTec 4D LV-Analysis) using real time 3-dimensional echocardiography.
Methods Real time 3D echocardiography examinations were performed in 24 volunteers. In the apical 3D full-volumetric images, LV end-diastolic volumes (EDV), end-systolic volumes (ESV) and EF were measured using 4DLVQ and TomTec. The repeatability and agreement of the new method were evaluated compared to TomTec.
Results 1. The analysis time of 4DLVQ was significantly shorter than for TomTec (156.63±33.72 s vs 275.55±50.64 s, p<0.05). 2. There were no significant difference in LVEDV (75.40±16.72 ml vs 71.65±14.81 ml), LVESV (30.25±6.69 ml vs 28.30±6.71 ml) and LVEF (59.65±4.96% vs 60.70±3.51%) between the two methods (p>0.05). 3. LVEDV, LVESV and LVEF measured by 4DLVQ had good correlation with those by TomTec. (r1=0.715, r2=0.618 r3=0.532, respectively, p<0.05 for all). 4. Bland-Altman analysis revealed high agreement in LV volume and EF between 4DLVQ and TomTec, with 95% limits of agreement of −19.8∼27.3 ml, −9.5∼13.4 ml and −9.4∼7.3% for EDV, ESV, and EF respectively. Comparison with TomTec, 4DLVQ showed lower intraobserver and interobserver variabilities, Intra-observer variability of 4DLVQ versus TomTec was 12.29% versus 21.96% for EDV, 16.92% versus 34.35% for ESV, and 6.50% versus 7.24% for EF. Inter-observer variability of 4DLVQ versus TomTec was 9.84% versus 18.13% for EDV, 10.47% versus 25.12% for ESV, and 6.50% versus 6.72% for EF. In comparison with TomTec, 4DLVQ showed higher intra-class correlation coefficient.
Conclusions 4DLVQ is a novel, simple, feasible and reproducible tool for LV volumes and EF.