[Three-dimensional ultrasonic diagnosis in gynecology and obstetrics]. 
Three-dimensional reconstruction of an organ requires a coordinated sequence of cross-sectional scans.  In ultrasound this can be solved by rotating the scan plane horizontally or vertically.  Two scan heads have been built, one to rotate the plane around a horizontal, the second around a vertical axis.  There are two ways to reconstruct the scans taken by ultrasound into a three-dimensional image: --to contour the surface of the organ in each scan and to reconstruct these contours to a ring-shaped structure.  This procedure needs a lot of time; moreover, contouring must be performed via cursor on the screen.  --calculate a transparent image of the organ.  To obtain the best spatial image by the "transparent method", the image must be moved on the screen.  Both methods of reconstruction are shown and compared in this paper.  First experiences show that they can be applied in tumour diagnostic and in the diagnosis of malformations in early pregnancy.  Further clinical studies will have to prove this.