P33.04: Prenatal diagnosis of mirror‐polydactyly of the feet

in about 15 minutes using 3D reconstructed volumes, but the evaluation time of volume data sets may be decreased significantly if the acquisition of volumes is standardized to minimize artefacts and produce uniform images. Evaluation of thoracic bones has been possible in all cases. The scapulae and clavicles can be easily visualized by multiplanar mode, but the relationships between the thoracic bones, especially with ribs, are better observed by rendering mode. Two fetuses affected by trisomy 21 have eleven ribs; one fetus with tetralogy of Fallot has also a spondylocostal dysostosis with hemivertebrae and four fused ribs; one fetus referred for ventriculomegaly had two thoracic hemivertebrae. In all cases ultrasound scans were confirmed after birth by radiological examinations. Conclusions: Three-dimensional ultrasound provides additional diagnostic information for the evaluation of fetal thoracic skeleton and it should be of value in the diagnosis of skeletal anomalies. Until now its use must be reserved in a research setting and offered to high-risk patients in order to understand which role 3D may play in the study of skeletal thoracic malformations as a screening or diagnostic tool.