title: Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation.
abstract: OBJECTIVE
  This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC).
  
  
  METHODS
  Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage.
  
  
  RESULTS
  Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique.
  
  
  CONCLUSIONS
  Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.
authors.affiliation: Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health/Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Luís F
authors.initials: LF
authors.lastname: Gonçalves
authors.forename: Wesley
authors.initials: W
authors.lastname: Lee
authors.forename: Tinnakorn
authors.initials: T
authors.lastname: Chaiworapongsa
authors.forename: Jimmy
authors.initials: J
authors.lastname: Espinoza
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Schoen
authors.forename: Peter
authors.initials: P
authors.lastname: Falkensammer
authors.forename: Marjorie
authors.initials: M
authors.lastname: Treadwell
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
mesh_terms: D015331:Cohort Studies; D019561:Echocardiography, Four-Dimensional / Q000379:methods*; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods; D012016:Reference Values; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods