Clinical Diagnosis Using Ultrasound 1999.5.31

Clinical Diagnosis Using Ultrasound 1999.5.31

In 1958, Donalda and others developed the world's first ultrasound diagnostic device, after which it rapidly evolved and the equipment was gradually improved. This marked the beginning of modern ultrasound technology. When people sing, the frequency of their vocal waves is between 16 and 20 kHz; sound waves above 20 kHz are called ultrasonic waves, which humans cannot hear but can propagate through solid bodies. The speed at which sound waves travel within the body depends on the density of the tissue—higher density means faster speed. Reflections generated at the interface between two types of tissue can be projected onto a screen by the ultrasound diagnostic device, giving ultrasound its diagnostic significance. Ultrasound is most useful for diagnosing conditions related to the liver, gallbladder, spleen, kidneys, and uterus.