超声心动图定量胎儿主动脉和肺动脉内径Z评分的研究

摘要

目的 通过对大样本正常胎儿的生物学生长参数与胎儿超声心动参数主动脉内径和肺动脉内径测量数据进行相关统计学分析,计算主动脉和肺动脉内径的Z评分正常参考值范围,为正常发育的胎儿心脏和先天性畸形心脏提供更加精准的定量化评估指标.方法 随机连续选取中晚孕期正常单胎胎儿1218例.通过测量胎儿的双顶径(BPD)、股骨长径(FL)和根据停经史计算胎儿的孕周(GA)获得正常胎儿的生物学生长参数.通过标准胎儿超声心动图测量收缩末期主动脉瓣环内径(AO)和肺动脉瓣环内径(PA).以BPD、FL及GA作为自变量,AO、PA作为应变量建立最佳模型,再分析标准差(SD)与自变量BPD、FL及GA的相关关系,通过以上统计数据,运用公式计算Z评分.结果 通过统计分析显示,直线回归方程能够良好地反映胎儿的非心血管定量参数BPD、FL、GA与心血管定量参数AO与PA之间的关系.SD随自变量增大而增大,也呈线性关系,运用绝对残差的加权回归消除SD的异方差性,建立直线回归方程.根据这些方程,AO的Z评分=(实际测量的AO-根据BPD,FL和GA预测的AO)/预测的AO的SD;PA的Z评分=(实际测量的PA-根据BPD,FL和GA预测的PA)/预测的PA的SD.结论 运用统计学方法,通过分析较大样本正常胎儿生物学生长参数BPD,FL及GA与胎儿超声心动图测量参数AO和PA,建立了AO和PA的Z评分正常参考值范围.Z评分有助于更加准确地评估正常胎儿心脏结构的生长发育,在先天性心脏病胎儿心血管径线的定量评估与分析方面存在潜在的应用价值.%Objective To establish detailed quantitative comparison of cardiac vessel diameters with non-cardiac biometrical measurements and develop computation of Z-scores reference ranges of aortic and pulmonary diameters in normal fetuses.Methods A retrospective cross-sectional study of 1218 singleton normal fetuses was performed.Non-cardiac fetal biometric parameters included biparietal diameter (BPD) and femoral length (FL) and an assessment of gestation age (GA) based on menstrual age.Fetal cardiac measurements of aortic (AO) and pulmonary valve annulus diameters (PA) at end-systole were analyzed.Normal Z-score ranges were developed for AO and PA using GA,BPD and FL as independent variables.Results Linear regression models between AO,PA and three independent variables (BPD,FL,GA) were established,correlations between fetal cardiac measurements and the independent variables were excellent.Standard deviation (SD) for assessment of heteroscedastieity of independent variables also could be modeled with a simple linear regression by using weighted regression of absolute residuals in order to minimize the effect of heteroscedasticity.Conclusions By applying statistical computations that are based on a correlation of non-cardiac biometrical measurements including FDL,BPD and GA between fetal echocardiographic parameters as AO and PA,development of fetal Z-scores reference ranges for AO and PA was realized.This permits detailed assessment of growth of developing fetal cardiac structures in normal hearts and potentially allows for the quantitative assessment of the congenitally complex heart defects that severely alter cardiac dimensions.