AbstractObjectiveTo determine the antenatal sonographic lung area measurement method in left congenital diaphragmatic hernia (CDH) with the highest interrater agreement among North American Fetal Therapy Network (NAFTNet) centers within and outside the fetoscopic tracheal occlusion (FETO) consortium and in comparison with a European “expert” reviewer (ER).MethodsNineteen members from nine FETO consortium centers and 29 reviewers from 17 non‐FETO centers reviewed ultrasound clips of the chest from 13 fetuses with isolated left CDH and were asked to select a static plane for lung area measurement using anteroposterior (AP), longest, and trace methods. Interrater agreement in lung area measurements was determined using intraclass correlation coefficient (ICC). Bland‐Altman analysis was used to evaluate mean difference (bias) between NAFTNet reviewers and ER.ResultsAmong FETO centers, agreement was highest using trace (ICC 0.94; 95% CI, 0.83‐0.98), followed by longest (ICC 0.89; 95% CI, 0.75‐0.97) and lowest for A‐P (ICC 0.83; 95% CI, 0.67‐0.94). Similar trends were noted in non‐FETO centers. When compared with ER, bias was lowest for trace: 14 ± 38 mm2 and 19 ± 36 mm2 for FETO and non‐FETO centers, respectively.ConclusionThe trace method demonstrated the highest interrater agreement and lowest bias for lung area estimation in left CDH across NAFTNet.
ObjectivesThis study investigated the reproducibility of standardization of lung‐to‐head ratio measurements in congenital diaphragmatic hernia (CDH) at our center among sonographers after we standardized the method.MethodsWe reviewed ultrasound images of 12 fetuses with CDH at Mayo Clinic from 2010 to 2016. Nine operators (1 maternal‐fetal medicine specialist with experience in measuring the lung‐to‐head ratio and 8 sonographers), who were blinded to previous findings, reviewed 33 selected images from 12 fetuses with left CDH. The method for lung‐to‐head ratio measurement was standardized before starting the measurements. The lung‐to‐head ratio was assessed by different methods to obtain the lung areas: anteroposterior, longest, and area tracing. We evaluated the correlation between operators using the intraclass correlation coefficient (ICC). We also compared agreement between the sonographers and a physician with experience in measuring the lung‐to‐head ratio using a Bland‐Altman analysis.ResultsThe methods with the best interoperator reproducibility were the standardized anteroposterior lung‐to‐head ratio (ICC, 0.69) and the standardized lung‐to‐head ratio tracing (ICC, 0.65) compared to the longest lung‐to‐head ratio (ICC, 0.56). The standardized lung‐to‐head ratio tracing had the best agreement among sonographers and the physician (bias, 0.11; limits of agreement, −0.27 to +0.49) than the anteroposterior lung‐to‐head ratio (bias, 0.35; limits of agreement, −0.13 to + 0.83) and the longest lung‐to‐head ratio (bias, 0.27; limits of agreement, −0.35 to +0.89).ConclusionsWe demonstrated that the lung‐to‐head ratio tracing method has high interoperator reproducibility and the best agreement among the operators at our center. Further multicenter studies are necessary to confirm our results.