Transparent three-dimensional ultrasound in fetal malformations.

Aim: Evaluation of three-dimensional ultrasound (3D-ultrasound) for optimal diagnosis in fetal malformations. Method: The 3D-system used consists of a transmitter, position sensor and 3D-workstation. In 38 fetal malformations, verified using real-time two dimensional ultrasound, 101 volume scans were recorded to prove the following functional abilities of the system: (1) Sequential analysis of single images including volume estimation; (2) Simultaneous three plane display (longitudinal, transverse and horizontal planes); (3) Cubic sectional image; (4) Rotating or swinging volume block. Results: In 85% of the cases the 3D-ultrasound dearly achieved a more reliable diagnosis in comparison to the two-dimensional images. Furthermore, the diagnostic information was considerably improved in 44% of the investigated malformations compared to the conventional two-dimensional method. The main advantages of the transparent 3D-technology are (1) Plastic global imaging of the pathological topography (fetal tumours, ureteral stenosis); (2) Exact measurement of irregular volumes (ventricle system, cerebellum); (3) Precise evaluation of fetal disproportions (triploidy, osteochondrodysplasia); (4) Detection of minor malformations. The disadvantages of the method is that all fetal movements during the scanning procedure affect adversely the three-dimensional display. Conclusion: The application of 3D-ultrasound in specialized prenatal units is recommended.