Self-gating MR imaging of the fetal heart: comparison with real cardiac triggering.
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.
Yamamura
Jin
J
Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany. j.yamamura@uke.uni-hamburg.de
Frisch
Michael
M
Ecker
Hannes
H
Graessner
Joachim
J
Hecher
Kurt
K
Adam
Gerhard
G
Wedegärtner
Ulrike
U
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