ABSTRACT
The first application of diagnostic ultrasound in medicine was in the late 1930s, when Karl Dussik, an Austrian psychiatrist and neurologist, became interested in the potential use of ultrasound for brain imaging. Ultrasound was already in use at that time, by mariners for underwater imaging and also by engineers for flaw detection in metals. The piezoelectric effect was already well known, having been discovered more than half a century earlier, and the concept of using a piezoelectric crystal both to transmit and receive ultrasound was described in 1917.
