<title>Three-dimensional ultrasound</title>

Abstract

Experimental and clinical studies have proved the practicability and feasibility of employing three-dimensional ultrasonic diagnostic techniques in a clinical context. Three-dimensional ultrasonic imaging originated from the idea that by rotating the scan plane around a fixed centre, a defined series of slices ( sectional images ) could be obtained that could be reconstructed to produce a three-dimensional display. Although three-dimensional reconstruction of parallel slices is the simplest solution - nuclear spin tomography and computerized tomography employ this technique - it is very difficult, on account of the unevenness of the surface of the body, to obtain parallel ultrasonic slices by means of ultrasound in clinical applications. Since a three- dimensional reconstruction is based on a coordinated sequence of slices, the simplest method of obtaining the three-dimensional ultrasonic display would seem to be by means of the above- mentioned rotated scan plane. This, however, requires a new scanning head to be designed in order to obtain such a slice sequence. TFte spatial relationship between the individual slices has to be fed into a hooked-up computer and suitable software for the contouring and spatial array of these slices needs to be developed.