title: Self-gating MR imaging of the fetal heart: comparison with real cardiac triggering.
abstract: OBJECTIVE
  To investigate the self-gating technique for MR imaging of the fetal heart in a sheep model.
  
  
  METHODS
  MR images of 6 fetal sheep heart were obtained at 1.5 T. For self-gating MRI of the fetal heart a cine SSFP in short axis, two and four chamber view was used. Self-gated images were compared with real cardiac triggered MR images (pulse-wave triggering). MRI of the fetal heart was performed using both techniques simultaneously. Image quality was assessed and the left ventricular volume and function were measured and compared.
  
  
  RESULTS
  Compared with pulse-wave triggering, the self-gating technique produced slightly inferior images with artifacts. Especially the atrial septum could not be so clearly depicted. The contraction of the fetal heart was shown in cine sequences in both techniques. The average blood volumes could be measured with both techniques with no significant difference: at end-systole 3.1 ml (SD±0.2), at end-diastole 4.9 ml (±0.2), with ejection fractions at 38.6%, respectively 39%.
  
  
  CONCLUSIONS
  Both self-gating and pulse-wave triggered cardiac MRI of the fetal heart allowed the evaluation of anatomical structures and functional information. Images obtained by self-gating technique were slightly inferior than the pulse-wave triggered MRI.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany. j.yamamura@uke.uni-hamburg.de
authors.forename: Jin
authors.initials: J
authors.lastname: Yamamura
authors.forename: Michael
authors.initials: M
authors.lastname: Frisch
authors.forename: Hannes
authors.initials: H
authors.lastname: Ecker
authors.forename: Joachim
authors.initials: J
authors.lastname: Graessner
authors.forename: Kurt
authors.initials: K
authors.lastname: Hecher
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Ulrike
authors.initials: U
authors.lastname: Wedegärtner
mesh_terms: D000818:Animals; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D011859:Radiography; D055425:Respiratory-Gated Imaging Techniques; D012756:Sheep