Investigation On The Automated Quantification Of Left Ventricular Volume With Three Dimensional Transthoracic Echocardiography

PartⅠ:Feasibility and accuracy of automated quantification of left ventricular volume by three-dimensional echocardiography[Objective] To explore the feasibility and accuracy of automated quantification of left ventricular volume by three-dimensional echocardiography,using manual three-dimensional echocardiography(3DEM)and cardiac magnetic resonance(CMR)as reference standards.[Methods] A total of 89 patients with three different kinds of heart diseases were enrolled in this study,including 30 patients with asymmetric hypertrophic cardiomyopathy(HCM),30 patients with hypertension(HT)and 29 patients with dilated cardiomyopathy(DCM).The left ventricular end-diastolic volume(LVEDV1),end-systolic volume(LVESV1)and ejection fraction(LVEF1)were measured by three-dimensional automated quantification(3DEA),manual three-dimensional echocardiography(3DEM)and cardiac magnetic resonance(CMR),respectively.The feasibility of each group was calculated.The measurements of three-dimensional automated quantification(3DEA)were compared with those of CMR and 3DEM,respectively,to explore its accuracy;for patients that automated quantification was not good enough,the operator made manual correction,and the left ventricular end-diastolic volume(LVEDV2),end-systolic volume(LVESV2)and ejection fraction(LVEF2)were recorded after manual correction(3DEA-C),and the feasibility of each group was analyzed.The measurements of three-dimensional automated quantification with contour correction(3DEA-C)were compared with those of CMR and 3DEM again.[result](1)The feasibilities of HCM,HT and DCM were 93.8%,100% and 93.5% respectively;(2)with three-dimensional automated quantification,LVEDV1 and LVESV1 in DCM group were significantly larger than those of the other two groups,and LVEF1 in DCM group was significantly lower than those of the other two groups(P < 0.05);(3)LVESV2 were significantly smaller than LVESV1 in HCM group,and LVEF2 were significantly higher than LVEF1 in HCM group(P < 0.05);(4)Comparing the measurements of 3DEA with those of 3DEM,there were four main findings: ⑴The values of left ventricular volume measured by 3DEA in each group were larger than those measured by 3DEM;⑵The measurements of 3DEA had good correlations with those of 3DEM in the whole study;⑶The correlations for LVESV and LVEF in HCM group were not good(r=0.46-0.61).After correction,the correlations were significantly improved.(r=0.82-0.93);⑷The correlations for the rest parameters of each group were good(r=0.86-0.98).And they were not significantly improved after counter correction(r=0.87-0.98);(5)Comparing the measurements of 3DEA with those of 3DEM,the findings were similar except that the volume values of each group measured by 3DEA were lower.[Conclusion](1)It is highly feasible to quantify three-dimensional echocardiography-derived left ventricular volume and ejection fraction in patients with hypertrophic cardiomyopathy(HCM),dilated cardiomyopathy(DCM)and hypertension(HT)with automated software;(2)The differences in left ventricular volume and ejection fraction between DCM group and the other two groups could be detected by the automated quantification technique;(3)with counter edition,the values of LVESV and LVEF in HCM group were significantly different from those before counter correction,but no significantly differences were seen in the rest parameters for each group;(4)The measurements of 3DEA correlated well with those of 3DEM and CMR,thus it could be used to quantify left ventricular volume and ejection fraction in patients with DCM and HT;(5)The measurements of 3DEA-C correlated well with those of 3DEM and CMR,thus it could be used to quantify left ventricular volume and ejection fraction in patients with HCM.Part Ⅱ: The clinic value of three-dimensional echocardiography in evaluating left ventricular volume and ejection function in patients with hypertrophic cardiomyopathy: A comparative study with two-dimensional biplane Simpson method[Objective] To explore the clinical value of automated three-dimensional echocardiographic quantification in patients with hypertrophic cardiomyopathy(HCM),comparing with the two-dimensional Simpson’s method,with magnetic resonance(MR)as the reference standard.[Methods] 28 patients with asymmetric hypertrophic cardiomyopathy(HCM)were enrolled in this study.The left ventricular end-diastolic volume(LVEDV),end-systolic volume(LVESV)and ejection fraction(LVEF)were measured by three-dimensional automatic quantification(3DEA),two-dimensional biplane Simpson’s method(2DBP)and cardiac magnetic resonance(CMR)respectively.T The Pearson correlation coefficient and Bland-Altman analysis were used to assess inter-technique agreement between these two ultrasound techniques and CMR.The analysis time of these two ultrasound techniques was recorded,and the inter-observer and intra-observer variability were also calculated.For patients with poor automated quantification,manual correction was performed.Left ventricular end-diastolic volume(LVEDV2),end-systolic volume(LVESV2)and ejection fraction(LVEF2)were recorded again after manual correction(3DEA-C).and the feasibility of each group was analyzed.The measurements of three-dimensional automated quantification with contour correction(3DEA-C)were compared with those of CMR and 3DEM again.Analysis time and reproducibility were also assessed.[result](1)Compared with the volume measured by CMR,echocardiographic measurements were much lower,and the left ventricular volumes measured by 2DBP were even lower than those measured by three-dimensional echocardiography;(2)The correlations for the parameters between 3DEA-C and CMR were better than those between 2DBP and CMR;(3)The analysis time of three-dimensional automated technique is obviously shorter than that of 2DBP.The average analysis time of 2DBP,3DEA and 3DEA-C were 213±30s 、 14±1s 、 154±36s,respectively;(4)The reproducibility of 3DEA and 3DEA-C were better than that of 2DBP.[Conclusion] Compared with 2DBP,the measurements of left ventricular volume and ejection fraction in patients with hypertrophic cardiomyopathy by 3DEA were superior in accuracy and repeatability,while analysis time was shorter.It has the potential to be used in clinical to quantify left ventricular volume and ejection fraction in patients with asymmetric or irregular ventricular shape.