Role Of Four-dimensional Echocardiography With High-definition Flow Imaging And Spatiotemporal Image Correlation In Detecting Fetal Pulmonary Veins

Objective:Total anomalous pulmonary vein connection(TAPVC)is a rare congenital heart defect,which is one of the main causes of neonate death.Prenatal diagnosis of fetal TAPVC remains challenging for most screening sonographers.Spatiotemporal image correlation(STIC)is a new technology for prenatal fetal cardiac examination.STIC with high-definition flow imaging(HDFI)opens the new horizon as a new method for fetal cardiac examination.The purpose of this study was to evaluate the use of four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation(4D-HDFI)in identifying pulmonary veins in normal and TAPVC fetuses.Methods:We retrospectively reviewed and performed 4D-HDFI in 204 normal and 12 fetuses with confirmed diagnosis of TAPVC.For the normal fetuses,two other traditional modalities including color Doppler flow imaging(CDFI)and HDFI were used to detect the number of pulmonary veins and comparisons were made between each of these traditional methods and 4D-HDFI.The number of pulmonary veins identified was recorded for later analysis.Cardiac volumes were available for postanalysis to obtain 4D-rendered images of the pulmonary veins.Results:For conventional echocardiography,HDFI modality was superior to CDFI in detecting more pulmonary veins in normal fetuses throughout the gestational period.4D-HDFI was the best method during the second trimester of pregnancy in identifying normal fetal pulmonary veins.4D-HDFI images vividly depicted the figure,course,and drainage of pulmonary veins in both normal and TAPVC fetuses.Conclusion:HDFI and the advanced 4D-HDFI technique could facilitate identification of the anatomical features of pulmonary veins in both normal and TAPVC fetuses;4D-HDFI therefore provides additional and more precise information than conventional echocardiography techniques.