Contrast-enhanced Versus Routine Real-time Three-dimensional Echocardiography For Assessment Of Right Ventricular Volume And Ejection Fraction: Accuracy And Reproducibility Validated By Magnetic Resonance Imaging

Objective 1,The aim of this study was to develop an appropriate method for the application of SonoVue as a contrast agent for the right ventricular ( RV ) opacification. 2,We evaluate the value of contrast agent–enhanced (cRT3DE) versus routine (rRT3DE) real-time three-dimensional echocardiography for the assessment of the right ventricular volume and function.Methods A total of 35 healthy volunteers,full voulume image of right ventricular was acquired by rRT3DE and by cRT3DE in three different dosage of the working contrast suspension of 1.25mg/5ml, 2.5mg/5ml and 5mg/5ml,respectively. The right ventricular endocardial border of RV was divided in six segments,the image quality of the two-dimensional echocardiography, expressed as endocardial visualization index (EVI), were graded according to a 3-point scale: 0=not visible,1=barely visible,2=well visualized. Thirty healthy volunteers were examined by cardiac magnetic resonance imaging (cMRI), cRT3DE and rRT3DE within 24 hours,respectively. Right ventricular end-diastolic and end-systolic volume (RVEDV and RVESV) and ejection fraction (RVEF) were calculated offline respectively by 3D Argus software for cMRI and Tom-Tec 4D RV-function CAP software for RT3DE.Results The total EVI at the dosage of 2.5mg/5ml was highest (9.7±1.8 vs. 8.2±2.2 at baseline, p< 0.001; vs. 8.3±2.2 at 1.25mg/5ml, p < 0.001; vs. 9.3±2.4 at 5mg/5ml, p >0.05). The improvement of endocardial visualization scores was significant in the apical, and free walls and RVOT compared to base-line (p < 0.01). As compared to cMRI, rRT3DE overestimated RVESV and underestimated RVEDV and RVEF (p<0.05, each); the measurements by cRT3DE had better correlations than those by rRT3DE (r = 0.95 vs. 0.82 , t=2.48, p<0.05 for RVEDV; r = 0.94 vs. 0.76, t =2.7, p<0.05 for RVESV; r = 0.91 vs. 0.70, t =2.43, p <0.05 for RVEF). Bland-Altman analysis showed that each measurement by cRT3DE had a smaller limit of the agreement with less inter- and intra-observer variability.Conclusion appropriate administration of SonoVue contrast agent enhances the ability for the RV contour detection; the combination of the RV acoustic opacification and the newly released RV analysis software facilitated cRT3DE estimation of the RV volumes and ejection fraction; as compared to rRT3DE, cRT3DE is more accurate and reproducible for the RV functional measurements using cMRI as reference standard.