In ovo non-invasive quantification of the myocardial function and mass of chick embryos using magnetic resonance imaging

William M. Holmes, Christopher McCabe, Jim M. Mullin, Barrie Condon and Maureen M. Bain
NMR in Biomedicine 2008, 22, 745-752

Magnetic resonance imaging has evolved as one of the major non-invasive tools to study healthy and diseased hearts in animal models, especially rodent models. Even though, the chick embryo has long been used as a model for cardiovascular research, MRI has not yet been used for in vivo cardiac studies. Part of the reason for this is the difficulty in monitoring the ECG and respiration of the chick embryo in the magnet for gating purposes. To overcome this complication, this paper presents the use of retrospective Cine MRI to measure the cardiac function of chick embryos in ovo for the first time, without the need for respiratory or cardiac gating. The resulting left ventricular functional parameters, from six chick embryos at 20 days of incubation, were (mean ± SD) EDV 69 ± 15 µL, ESV 31 ± 7 µL, SV 38 ± 9 µL and EF 54.5 ± 2%. The use of retrospective Cine MRI at earlier stages of development is also discussed and difficulties have been highlighted.