Jin Yamamura MD, Presenter: Nothing to Disclose

Michael Frisch, Abstract Co-Author: Nothing to Disclose

Inga Kopp, Abstract Co-Author: Nothing to Disclose

Joachim Graessner MS, Abstract Co-Author: Employee, Siemens AG, Germany

Kurt Hecher MD, Abstract Co-Author: Nothing to Disclose

Gerhard B. Adam MD, Abstract Co-Author: Nothing to Disclose

Ulrike Wedegaertner MD, Abstract Co-Author: Nothing to Disclose

The aim of this study was to perform fetal cardiac MR imaging with triggering of the fetal heart beat in utero with a novel MR compatible cadiotocogramm (CTG) in a sheep model.

Images of the fetal sheep heart were performed on 5 pregnant ewes at a 1.5 T scanner (Siemens, Erlangen, Germany). All ferromagnetic materials were removed in a commercial CTG and it was made MR compatible. By using this CTG, a cardiac triggered, breath-hold cine MRI with steady-state free precession (SSFP) of the fetal heart were achieved in short axis view, two, four and three chamber view. From the short-axis, the left ventricular volume and thus the function was measured.

The fetal heart frequencies were between 130 and 160 beats per minute. The novel MR compatible CTG allowed a stable signal during the whole MRI measurement. It was possible to perform the CTG triggered fetal cardiac MRI in all fetuses. In cine sequences the contraction was shown. The average blood volumes at end systole was 2.9 ml (SD±0.2), at end diastole 4.6 ml (±0.2); with ejection fractions between 38.4% and 40%, respectively. The mitral, the tricuspid, aortic and the pulmonary valves as well as the foramen ovale were clearly depicted.

The novel MR compatible CTG allowed an excellent trigger of the fetal heart rate. An evaluation of anatomical structures and functional information could be obtained from the cMRI.

A CTG triggered fetal cardiac MRI might be of great impact in the evaluation of fetuses with complex congenital heart defects and might help the surgery in utero.

Yamamura, J, Frisch, M, Kopp, I, Graessner, J, Hecher, K, Adam, G, Wedegaertner, U, A Novel Technique for Cardiac MRI of the Fetal Heart: MR Compatible Doppler Ultrasound (CTG) for Cardiac Triggering  .  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9011947.html