[3d ultrasound in prenatal diagnosis].
Three-dimensional sonography is a logical development of conventional sonography, and is a consequence of the fact that every examiner tries to imagine the three-dimensional appearance of an organ on the basis of the tomographic images of it. In a long development process starting with the first 3D images in 1986/87 and lasting until today, we succeeded in developing a 3D system suitable for routine examinations, which the manufacturer is now marketing commercially. With a 3D transducer a coordinated sequence of tomograms is obtained; all the images are then computed transparently and subsequently imaged three-dimensionally as a crystalline volume. Movement of the 3D image on the computer screen is important for three-dimensional identification. The volume thus computed can then be bisected in longitudinal, transverse and horizontal planes and thus examined in real-time without any interference such as fetal movements. The horizontal sections cannot be obtained by conventional sonography. On the basis of more than 600 patients examined by this new method it was established that 3D imaging of malformations improves diagnosis and assessment, that examinations deliver accurate and reproducible results, and that section analysis can substantially facilitate diagnosis of fetal malformations.