Medical ultrasonics: an historical review

The technology of ultrasonics has grown up over the past 50 years and, almost from the start, there has been considerable interest in applying the radiation-like properties of ultrasound for medical purposes in modes analogous to those familiar with ionizing radiation. Until recently, at least, much of the development in this field has been on a superficial level and without reference to any scientific understanding of the situation. This has been particularly the case in attempts to use ultrasound therapeutically and, in the diagnostic field, which is historically a more recent development, very considerable advances may be expected in the future as the full potential of the subject is realized.