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.