We described a very rare case of aorto-pulmonary communication with right aortic arch and crossed pulmonary artery that cannot be placed in the typical anatomic classification of aortopulmonary window. At 23 weeks gestation, fetal echocardiography revealed a large tunnel-like communication connecting the great vessels proximal to the main pulmonary artery bifurcation, rather than a classic aortopulmonary window between the ascending aorta and the main pulmonary artery.

To study the interaction between hemodynamics and morphology in abnormal development of the heart, it is essential to have an animal model with specific and reproducible cardiac malformations. A standardized method was developed for inducing such an anomaly in the chick embryo. For this purpose, all-trans retinoic acid, dissolved in 2% dimethylsulphoxide, was applied on the vitelline membrane of the embryo in concentrations of 1.0 μgm and 0.3 μgm. A total of 207 embryos, staged according to Hamburger and Hamilton, were treated at stages 10 (33 hours of incubation) and 15 (50–55 hours of incubation). Three control groups consisted of embryos solely treated with dimethylsulphoxide, sham operated chicks, and untreated embryos, respectively. The embryos were sacrificed on the 9th, 10th and 11th days of incubation and hearts were examined by microdissection. Additional histologic studies were undertaken in 110 cases. Embryos treated with retinoic acid at both stages of development showed a high percentage of lesions falling within the general spectrum of double outlet right ventricle. The abnormality varied from merely a rightward shift of the aorta to cases with an additional subaortic ventricular septal defect, which, in combination with the rightward positioned aorta, was classified as a double outlet right ventricle. Histologic examination showed the presence of muscular tissue between the leaflets of the aortic and mitral valves. No other types of cardiac malformations were seen. Our results, with respect to timing, resemble data from studies made of hearts after surgical ablation of neural crest at comparable stages. Both method and timing of treatment with retinoic acid are important factors for the induction of specific and reproducible cardiac anomalies. This chick model allows for further detailed study of development of double outlet right ventricle, as well as the assessment of early detectable hemodynamic changes.

We describe a new method of three-dimensional magnetic resonance imaging of the heart that has been used to produce high quality diagnostic images in 274 patients with congenital cardiac disease, ranging in age from 1 day to 66 years. Using a steady state free precession gradient echo technique and parallel imaging, rapid acquisition of the entire cardiac volume is possible during 8 to 15 sequential breath-holds, each lasting between 8 and 15 s. We obtained high-resolution images, with a resolution of 1 mm3, at between 3 and 10 phases of the cardiac cycle.

While images of diagnostic quality were obtained in all cases, in 52 patients there was some degradation due to various factors. Children under 8 years were ventilated, and ventilation was suspended for the breath-holds. For patients breathing spontaneously a novel respiratory navigator technique was developed, using a navigator echo placed over the right hemidiaphragm. This was used successfully in 20 patients, and reduced the misalignment of images obtained during different breath-holds.

Images were analysed using multi-planar reformatting and volume rendering. Image processing took approximately five minutes for each study. End-diastolic images were processed for all patients. Systolic images were also processed in selected cases.

Further improvements in parallel imaging should reduce imaging times further, so that it is possible to obtain the full volume image in a single breath-hold. This will enable imaging of complex anatomy to be obtained using a standard imaging protocol that does not require the operator to understand the cardiac malformation, making the magnetic resonance imaging of congenital cardiac disease faster and more effective.