Biomedical Prospects for Ultrasound Holography

Abstract

The basic problems associated with ultrasonic imaging by holographic methods are presented and the implications relative to possible diagnostic application are discussed. Several possible techniques for recording the magnitude and phase of sonic fields are analyzed and recent results obtained with a mechanical scanning system are presented. The distortion and aberration of the reconstructed images which are associated with wavelength scaling present a technological obstacle to be overcome. The nature of image presentation that has been used in the reconstruction of visible images has neither used the entire information contained in the hologram nor achieved desirable image geometry. An intermediate image processing scheme may provide a useful approach toward the solution of these problems. The nature of propagation of ultrasound in biologic tissue and the resulting image information present in an ultrasound field emanating from such a subject have yet to be fully understood or analyzed. There is little doubt, however, that given a suitably rapid detection and image presentation system, very considerable diagnostic information can be obtained by this method.