Magnetic resonance angiography of fetal vessels: feasibility study in the sheep fetus.

PURPOSE

The aim of this study was to perform fetal magnetic resonance angiography (MRA) in utero in a sheep model.

MATERIAL AND METHODS

Images of the great vessels, the heart, and the tracheal tree were performed on four pregnant ewes with a 1.5-T scanner (Philips Medical Systems, Best, The Netherlands). MRA was achieved in utero using a nontriggered free-breathing three-dimensional balanced fast field echo (FFE) technique. All obtained MRA images were evaluated in consensus on a three-point scale by two radiologists with 9 and 4 years of experience in fetal MRI, respectively.

RESULTS

The fetal heart frequencies were between 130 and 160 bpm. The aorta from the aortic bulb to the bifurcation as well as some of the main aortic branches could be depicted. The pulmonary trunk and arteries, the superior and inferior caval veins, and the subsegmental branches of the trachea could also be visualized.

CONCLUSION

The nontriggered MRA of the fetal great vessels with images of the tracheal tree allowed an excellent evaluation of anatomical structures.