Area of the fetal ascending and descending aorta by spatiotemporal image correlation in the rendering mode: Reproducibility and comparison with pregestational diabetic mothers

Background: The objective of this study was to assess the ascending and descending aorta area measurements by three-dimensional (3D) ultrasound using spatiotemporal image correlation (STIC) in the rendering mode comparing these measurements with pregestational diabetic mothers and assessing the reproducibility of the method. Methods: We carried out a retrospective cross-sectional study with 58 normal and nine fetuses from pregestational diabetic mothers between 20 and 33 + 6 weeks of gestation. Fetal heart volumes were acquired at the level of four-chamber view to obtain the reconstructed planes for the ascending and descending aorta areas in the rendering mode. Linear regression was performed to assess the correlation between the fetal aorta areas and gestational age (GA). To assess the intra- and interobserver reproducibility, we used the concordance correlation coefficient (CCC). Results: The mean ascending and descending aorta areas were 0.12 (0.02–0.48) and 0.11 (0.04–0.39) cm2 in normal fetuses, respectively. There was a moderate positive correlation between GA and ascending aorta area measurements (0.005676*GA – 0.01283; r = 0.53, P < 0.0001) and strong positive correlation between GA and descending aorta area (0.01095*GA – 0.1581; r = 0.68, P < 0.0001). We observed a weak intra- and interobserver reproducibility with CCC ranging from 0.05 to 0.91. The mean difference in the ascending and descending aorta area measurements of normal and fetuses of pregestational diabetic mothers was −0.03 cm2 (P = 0.276) and −0.03 cm2 (P = 0.231), respectively. Conclusion: The fetal ascending and descending aorta area measurements obtained by 3D ultrasound using STIC in the rendering mode increased with GA in normal fetuses. The method showed weak intra- and interobserver reproducibility.