A comparative study of two methods to quantify Z scores of aortic root diameters measured in children by echocardiography / 中华医学超声杂志（电子版）

ABSTRACT

Objective To investigate the calculation method and its inlfuencing factors of Z scores in the aortic root diameters measured by echocardiography in children. Methods A total of 105 children with median age 19 months, who came to Shenzhen Children′s Hospital from March 2012 to October 2012 were included. The diameters of aortic ring (ARD) and aortic sinus (ASD) were measured by two dimension echocardiography, Z scores of ARD and ASD were calculated using two different normal reference values regression equation and mean square error derived from Shenzhen children′s hospital (C method) and Pettersen et al (P method). The regression equation from C method and body surface area (BSA) formula from P method were adopted to calculate Z scores of ARD and ASD (ZH method). The Z results of ARD and ASD calculated by those three methods were compared and were analyzed for their normality probability distributions. Results Z scores of ARD and ASD derived from C method were all showed as normal distribution (P=0.067 and 0.650). Z scores of ARD and ASD derived from P method were all showed as normal distribution (P=0.208 and 0.970). Z score of ARD derived from ZH method was showed as non-normal distribution (P=0.027), but Z score of ASD was normal distribution (P=0.430). There were no significant differences in ARD-Z calculated by C method (0.41±0.89), P method (0.23±0.85) and ZH method (0.36±0.94) (F=1.117, P=0.309). There were signiifcant differences in the Z scores of ASD calculated by C method (0.38±0.89), P method (0.58±0.71) and ZH method (0.36±0.84) (F=5.443, P=0.005). Z scores of ARD (r=0.917, P=0.000) and ASD (r=0.900, P=0.000) calculated by C method correlated well with that by P method. Conclusions Calculation method of BSA and normal reference values regression equation were the main influencing factors of Z score value in quantifying children aortic root diameters by echocardiography. For the clinical applications. The normal reference value should be used which is suitable for the Chinese children.