Study on the feasibility of automatic quantification of cardiac axis by fetal intelligent navigation echocardiography / 中华超声影像学杂志

ABSTRACT

Objective:To explore the feasibility of fetal intelligent navigation echocardiography (FINE) in automatic quantitation of cardiac axis (CA).Methods:A total of 62 pregnant women of which 2 with twins′ pregnancy in the second and third trimesters from May to June 2020 in Sir Run Run Shaw Hospital Zhejiang University College of Medicine were enrolled in this non-selective and prospective study. After excluding those who could not be analyzed, they were assigned into four groups according to their CA measuring methods: ①Group with manual measuring CA in systole (CAS); ②Group with manual measuring CA in diastole(CAD); ③Group with CA measured by FINE in three-steps; ④Group with CA measured by FINE in seven-steps. The CAS among groups were compared in order to analyze the consistency and correlation of CAS achieved by different methods, meanwhile, the intra-observer and inter-observer consistency and repeatability were also evaluated.Results:A total of 64 fetuses with 187 volume data were collected, of which 60 cases of fetal data can be included in the study, 57 cases of normal CA, 3 cases of abnormal CA, a total of 158 volume data can be used for data analysis, the success rate was about 84.5%. Because of the small number of abnormal CA cases (3 cases), only 57 cases of normal CA were statistically analyzed in this study. Three-step and seven-step FINE automatic quantitative CA showed significantly different from those obtained with manual measurements of CAD ( P=0.005, P<0.001). There were no significant differences in quantitative analysis of CA between three-step or seven-step FINE and manual measurements of CAS ( P=0.458, 0.883), however, there was no correlation between CA using three-step FINE and manual measurement of CAS ( rs=0.056, P=0.679), but there was a positive correlation between CA using seven-step FINE and manual measurement of CAS ( rs=0.599, P<0.001). The linear regression equation was constructed as follows Y=10.96+ 0.73 X ( R2=0.431, P<0.001). There was no correlation between three-step method and seven-step method for automatic quantitative CA ( rs=0.158, P=0.241). There was significant difference( P<0.001), but strong correlation between manual measurement of CAS and manual measurement of CAD ( rs=0.973, P<0.001), the average difference was &Delta;CA=(4.5± 3.8)°. The linear regression equation was constructed as follows Y=-2.94+ 0.96 X ( R2=0.950, P<0.001). Intra-observer and inter-observer measurements had shown no significant difference in consistency and repeatability (all P>0.05). Conclusions:The measurement of fetal CA by seven-step FINE is superior to the three-step FINE when the fetal CA is in normal range. This may be considered a promising aspect that seven-step FINE automatic quantitation of fetal CA can replace the manual measurement of CAS. Future research is needed to deliminate the reliability of automatic quantification of fetal CA by seven-step FINE with the CA in abnormal range.