الفهرس 
Physical principles of ultrasoundOnly 14 pages are availabe for public view
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Abstract
Historically it was noticed that the ultrasound idea taken from bats which utilize sound during their flight and this sound produced by the bat was probably imperceptible Jo the human ear. The piezo-electric effect upon which the generation and detection of an ultrasound signal depends was noted by Pierre and Jacues curie.The first attempt to use ultrasound for diagnosis could be traced back to Dussik et al., as they had formed ultrasonic shadowgraphs similar X-ray photographs. The first ultrasonic- instrument called the supersonic reflectoscope.Howry is credited as being one of the pioneers of diagnostic ultrasound. He developed the principle of compound scanning to improve image quality by a series of studies on animals. This was carried out to verify the anatomic accuracy of ultrasonic pictures. The animals were scanned in water tanks while they were overdosed with anaesthesia, their bodies were then frozen and comparable anatomic cross sections were obtained.