ABSTRACT
Objective To evaluate the concordance of two-dimensional echocardiography (2DE) and intelligent spatiotemporal image correlation (iSTIC) in measuring fetal aortic and aortic arch diameters during the second and third trimesters.Methods Data were collected by a prospective cross-sectional study of 140 normal singleton fetuses with the gestational age from 22 to 32 weeks.A total of 6 dimensions of the fetal aortic and aortic arch,including aortic annular diameter (AO),ascending aorta diameter (AAO),aortic arch diameter [AO Arch (INA to LCCA)],aortic arch diameter [AO Arch (LCCA to LSA)],aortic isthmus diameter and descending aorta diameter (DAO),were measured by two different methods.Concordance was assessed by comparing the measurements acquired by iSTIC with those determined by 2DE and depicted by Bland-Altman plots.Inter-and intra-observer variability was evaluated by the intraclass correlation coefficient (ICC) test.Results A total of 137 iSTIC volumes in 140 cases were found to be suitable for further analysis.Good correlation was observed in the measurements that determined by 2D or iSTIC (Pearson's R2 =0.977-0.983).There was no significant difference in the mean values of all the parameters that measured by two methods.Bland-Altman plot showed that the 95％ limits of agreement (LOA) in AO,AAO,AO Arch (INA to LCCA),AO Arch (LCCA to LSA),aortic isthmus diameter and DAO were (-0.1260/+ 0.2299),(-0.1707/+ 0.2241),(-0.1547/+ 0.2190),(-0.1736/+ 0.2024),(-0.1514/+ 0.2039) and (-0.1485/+ 0.2228),respectively.The points in the outside of LOA were 5.11％ (7/137),4.38％ (6/137),5.11％ (7/137),5.84％ (8/137),4.38％ (6/137)and 4.38％ (6/137),respectively.Conclusions iSTIC has a good agreement with 2DE in measuring fetal aortic and aortic arch dimensions during the second and third trimesters.