title: Prenatal Diagnosis of Fetal Interrupted Aortic Arch Type A by Two-Dimensional Echocardiography and Four-Dimensional Echocardiography with B-Flow Imaging and Spatiotemporal Image Correlation.
abstract: BACKGROUND
  Fetal interrupted aortic arch (IAA) is a rare cardiac anomaly and its prenatal diagnosis is challenging. The purpose of our report is to evaluate the use of two-dimensional echocardiography (2DE) and 4D echocardiography with B-flow imaging and spatiotemporal image correlation (4D BF-STIC) in detecting IAA type A (IAA-A).
  
  
  METHODS
  Twenty-three cases of confirmed IAA-A identified by fetal echocardiography were involved in the study. The fetal echocardiography image data were reviewed to analyze the ratio of right ventricle to left ventricle (RV/LV) diameter, the ratio of main pulmonary artery to ascending aorta (MPA/AAO) diameter, and the correlation of RV/LV diameter ratio and size of ventricular septal defect (VSD). 4D BF-STIC was performed in 21 fetuses using the sagittal view (4D BF-STIC-sagittal) and the four-chamber view (4D BF-STIC-4CV) as initial planes of view. An additional 183 normal fetuses were also included in our study. RV/LV and MPA/AAO ratios were calculated and compared with that of IAA-A fetuses. Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV were used to visualize the aortic arch and its associated neck vessels. Six subgroups were evaluated according to gestational age.
  
  
  RESULTS
  Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV made the correct prenatal diagnosis of IAA-A in 19/23 (82.6%), 14/21 (66.7%), and 19/21 (90.5%) of patients, respectively. A significantly enlarged MPA combined with symmetric ventricles was found in the IAA-A fetuses, while the size of the VSD was negatively correlated with RV/LV ratio. 4D BF-STIC-sagittal and 4D BF-STIC-4CV were better than traditional 2D ultrasound in detecting the aortic arch and neck vessels between 17 and 28 gestational weeks and 29 to 40 gestational weeks in normal fetuses.
  
  
  CONCLUSIONS
  It is demonstrated that IAA-A could be diagnosed by traditional fetal echocardiography, while 4D technique could better display the anatomic structure and the spatial relationships of the great arteries. Use of volume reconstruction may promote its clinical usage and help prenatal diagnosis.
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Dongyu
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Ren
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Sun
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Sonography, Shengjing Hospital of China Medical University, Heping District, Shenyang, China.
authors.forename: Ailu
authors.initials: A
authors.lastname: Cai
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000002:abnormalities / Q000000981:diagnostic imaging*; D019561:Echocardiography, Four-Dimensional; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities / Q000000981:diagnostic imaging*; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal; D055815:Young Adult
keywords: B-flow; STIC; fetal echocardiography; interrupted aortic arch; spatiotemporal image correlation