title: Automated sonography: defining the spatial relationship of standard diagnostic fetal cardiac planes in the second trimester of pregnancy.
abstract: OBJECTIVE
  This study defines the spatial relationship of the diagnostic planes of the fetal heart to the 4-chamber view plane in the second trimester of pregnancy as a first step in the automation process.
  
  
  METHODS
  Three-dimensional static volumes of the fetal chest were acquired at the level of the 4-chamber view on 75 fetuses between 18 and 23 weeks' gestation. The spatial relationship of the diagnostic cardiac planes to the 4-chamber view plane were determined for each gestational week by using rotations along the x-, y-, and z-axes and a parallel slide (millimeters) when applicable.
  
  
  RESULTS
  The 5-chamber view (cardiac 1 plane) was best obtained by an initial parallel slide of the reference plane (plane A) toward the fetal head followed by a rotation along the y-axis. The right ventricular outflow tract (cardiac 2) and the abdominal circumference (cardiac 3) planes were best obtained by a parallel slide only: toward the fetal head in cardiac 2 and toward the fetal abdomen in cardiac 3.
  
  
  CONCLUSIONS
  This study shows the spatial relationship of fetal cardiac diagnostic planes to the 4-chamber view plane in the second trimester of pregnancy in 3-dimensional volumes. Testing the clinical applicability of automated software based on these formulas is the next step.
authors: Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Hofheimer Hall, Suite 310, 825 Fairfax Ave, Norfolk, VA 23507, USA.
authors: Alfred
authors: A
authors: Abuhamad
authors: Peter
authors: P
authors: Falkensammer
authors: Yueqin
authors: Y
authors: Zhao
mesh_terms: D001011:Aorta / Q000196:embryology; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D005318:Fetal Heart / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006352:Heart Ventricles / Q000196:embryology; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D016216:Ultrasonography, Prenatal / Q000379:methods*