title: Use of a high-frequency linear transducer and MTI filtered color flow mapping in the assessment of fetal heart anatomy at the routine 11 to 13 + 6-week scan: a randomized trial.
abstract: OBJECTIVE
  To prospectively assess the contribution of a high-frequency linear transducer and of moving target indicator (MTI) filtered color flow mapping in the visualization of cardiac fetal anatomy at the routine 11 to 13 + 6-week scan.
  
  
  METHODS
  This was a cross-sectional prospective study, including 300 singleton fetuses at 11 to 13 + 6 weeks' gestation. Patients were randomized into four groups and a detailed fetal cardiac examination was conducted transabdominally using either a conventional curvilinear transducer, a conventional curvilinear transducer and MTI filtered color flow mapping, a high-frequency linear transducer or a high-frequency linear transducer and MTI filtered color flow mapping. Regression analysis was used to investigate the effect on the ability to visualize different cardiac structures of the following parameters: gestational age at ultrasound examination; fetal crown-rump length (CRL); maternal body mass index (BMI); transducer-heart distance; the technique used at ultrasound; and the position of the placenta.
  
  
  RESULTS
  The four-chamber view was visualized in 89.0% of fetuses and regression analysis showed this rate was correlated with CRL and the use of MTI filtered color flow mapping during ultrasonography, and inversely correlated with BMI and transducer-heart distance. Use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the four-chamber view in 97.3% of fetuses, while this was only possible in 84.0% of fetuses using a high-frequency linear transducer. The left and right outflow tracts were visualized in 62.3 and 57.7% of fetuses, respectively. Regression analysis showed that the ability to visualize the left or the right outflow tract was correlated with the use of MTI filtered color flow mapping during scanning and was inversely correlated with transducer-heart distance. The use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the left and right outflow tracts in 96.0 and 97.3% of fetuses, respectively, while this was only possible in 37.3 and 26.7% of fetuses using a high-frequency linear transducer.
  
  
  CONCLUSIONS
  During the routine 11 to 13 + 6-week scan, the use of MTI filtered color flow mapping but not of a high-frequency linear transducer, improves visualization of cardiac anatomy.
authors.affiliation: Department of Obstetrics and Gynaecology, University Hospital Brugmann, Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Votino
authors.forename: Y
authors.initials: Y
authors.lastname: Kacem
authors.forename: O
authors.initials: O
authors.lastname: Dobrescu
authors.forename: H
authors.initials: H
authors.lastname: Dessy
authors.forename: T
authors.initials: T
authors.lastname: Cos
authors.forename: W
authors.initials: W
authors.lastname: Foulon
authors.forename: J
authors.initials: J
authors.lastname: Jani
mesh_terms: D001783:Blood Flow Velocity; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D005318:Fetal Heart / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007089:Image Enhancement; D010920:Placenta / Q000000981:diagnostic imaging; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D018615:Ultrasonography, Doppler, Color / Q000295:instrumentation*