title: Cardiovascular System Sonographic Evaluation Algorithm: A New Sonographic Algorithm for Evaluation of the Fetal Cardiovascular System in the Second Trimester.
abstract: OBJECTIVE
  To evaluate the reproducibility and feasibility of the new cardiovascular system sonographic evaluation algorithm for studying the extended fetal cardiovascular system, including the portal, thymic, and supra-aortic areas, in the second trimester of pregnancy (19-22 weeks).
  
  
  METHODS
  We performed a cross-sectional study of pregnant women with healthy fetuses (singleton and twin pregnancies) attending our center from March to August 2011. The extended fetal cardiovascular system was evaluated by following the new algorithm, a sequential acquisition of axial views comprising the following (caudal to cranial): I, portal sinus; II, ductus venosus; III, hepatic veins; IV, 4-chamber view; V, left ventricular outflow tract; VI, right ventricular outflow tract; VII, 3-vessel and trachea view; VIII, thy-box; and IX, subclavian arteries. Interobserver agreement on the feasibility and exploration time was estimated in a subgroup of patients. The feasibility and exploration time were determined for the main cohort. Maternal, fetal, and sonographic factors affecting both features were evaluated.
  
  
  RESULTS
  Interobserver agreement was excellent for all views except view VIII; the difference in the mean exploration time between observers was 1.5 minutes (95% confidence interval, 0.7-2.1 minutes; P < .05). In 184 fetuses (mean gestational age ± SD, 20 ± 0.6 weeks), the feasibility of all views was close to 99% except view VIII (88.7%). The complete feasibility of the algorithm was 81.5%. The mean exploration time was 5.6 ± 4.2 minutes. Only the occiput anterior fetal position was associated with a lower frequency of visualization and a longer exploration time (P < .05).
  
  
  CONCLUSIONS
  The cardiovascular system sonographic evaluation algorithm is a reproducible and feasible approach for exploration of the extended fetal cardiovascular system in a second-trimester scan. It can be used to explore these areas in normal and abnormal conditions and provides an integrated image of extended fetal cardiovascular anatomy.
authors.affiliation: Department of Obstetrics and Gynecology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain (C.B., F.G., L.O.Q., J.D.L.-L.); and Department of Obstetrics and Gynecology, Hospital Central de la Defensa Gómez Ulla, Universidad de Alcalá de Henares, Madrid, Spain (C.B.). jdeleonluis@yahoo.es.
authors.forename: Juan
authors.initials: J
authors.lastname: De León-Luis
authors.affiliation: Department of Obstetrics and Gynecology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain (C.B., F.G., L.O.Q., J.D.L.-L.); and Department of Obstetrics and Gynecology, Hospital Central de la Defensa Gómez Ulla, Universidad de Alcalá de Henares, Madrid, Spain (C.B.).
authors.forename: Coral
authors.initials: C
authors.lastname: Bravo
authors.affiliation: Department of Obstetrics and Gynecology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain (C.B., F.G., L.O.Q., J.D.L.-L.); and Department of Obstetrics and Gynecology, Hospital Central de la Defensa Gómez Ulla, Universidad de Alcalá de Henares, Madrid, Spain (C.B.).
authors.forename: Francisco
authors.initials: F
authors.lastname: Gámez
authors.affiliation: Department of Obstetrics and Gynecology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain (C.B., F.G., L.O.Q., J.D.L.-L.); and Department of Obstetrics and Gynecology, Hospital Central de la Defensa Gómez Ulla, Universidad de Alcalá de Henares, Madrid, Spain (C.B.).
authors.forename: Luis
authors.initials: L
authors.lastname: Ortiz-Quintana
mesh_terms: D000328:Adult; D000465:Algorithms; D002319:Cardiovascular System / Q000000981:diagnostic imaging* / Q000196:embryology*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D015588:Observer Variation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000502:physiology*; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal
keywords: fetal cardiovascular system; fetal echocardiography; obstetric ultrasound; second-trimester scan; sonographic protocol