Z-scores for fetal atrial volume using real-time three-dimensional echocardiographic Xplane imaging in normal fetuses / 中华超声影像学杂志

ABSTRACT

Objective To establish Z-scores reference ranges for fetal atrial volume in normal fetuses for accurate assessment of fetal cardiac structure and function . Methods Two hundred ninty-three normal fetuses with gestational ages between 18 to 38 weeks were investigated .Biparietal diameter (BPD) , femur length (FL) and gestational age (GA) were measured .Left atrial volume (LAV) and right atrial volume ( RAV ) were obtained using echocardiographic Xplane imaging . Subsequently , the optimal regression equation was established with BPD ,FL and GA as the independent variable and LAV and RAV as the dependent variable ,and then Z-scores of LAV and RAV were calculated . Results The linear regression equation of LAV and FL was Y＝0 .056×FL －1 .791 ( r ＝0 .952) ;the linear regression equation of RAV and FL was Y＝0 .057×FL －1 .833 ( r ＝0 .942) ;the linear regression equation of LAV and BPD was Y＝0 .046×BPD－2 .289 ( r ＝0 .910) ;the linear regression equation of RAV and BPD was Y＝0 .047×BPD－2 .348 ( r ＝0 .903) ;the linear regression equation of LAV and GA was Y ＝ 0 .122 × GA －2 .403 ( r ＝0 .952) ;the linear regression equation of RAV and GA was Y ＝0 .125×GA －2 .456 ( r ＝0 .942) . There was significant heteroscedasticity of standard deviation ( SD ) with increasing independent variables ,then weighted regression of absolute residuals was used in order to minimize the effect of heteroscedasticity ,and the linear regression equation was established . The linear regression equation of LAV-SD and FL was Y＝0 .005×FL －0 .119 ( r ＝0 .272) ;the linear regression equation of RAV-SD and FL was Y＝0 .005×FL －0 .104 ( r ＝0 .240) ;the linear regression equation of LAV-SD and BPD was Y＝ 0 .00375×BPD －0 .125 ( r＝0 .210) ;the linear regression equation of RAV-SD and BPD was Y＝0 .00375×BPD －0 .10875 ( r ＝0 .192) ;the linear regression equation of LAV-SD and GA is Y＝0 .0125×GA －0 .21125 ( r ＝0 .346) ;the linear regression equation of RAV-SD and GA was Y＝0 .0125×GA －0 .20875 ( r ＝0 .308) . According to these equations ,the Z-score calculation formula for LAV was ( measured LAV-predicted LAV from BPD , FL and GA)/SD of predicted LAV ; Z-score calculation formula for RAV was ( measured RAV －predicted RAV from BPD ,FL and GA)/SD of predicted RAV . Conclusions Fetal Z-scores references for the LAV and RAV can be established using common fetal biometrical parameters ( including FL ,BPD and GA utilizing statistical methods based on a large sample size) . This enhances accurate assessment of growth and development of fetal cardiac structures ,and provides novel insights for the determination of fetal atrial volume in fetuses with congenital heart disease .