- High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during
* * *- diagnostic u. the use of u. to obtain images for medical diagnostic purposes, employing frequencies ranging from 1.6 to about 10 MHz.
* * *ul·tra·sound 'əl-trə-.sau̇nd n1) vibrations of the same physical nature as sound but with frequencies above the range of human hearing compare INFRASOUND2) the diagnostic or therapeutic use of ultrasound and esp. a noninvasive technique involving the formation of a two-dimensional image used for the examination and measurement of internal body structures and the detection of bodily abnormalities called also echography, sonography, ultrasonography3) a diagnostic examination using ultrasoundultrasound adj of, relating to, performed by, using, or specializing in ultrasound <an \ultrasound technician> <\ultrasound imaging>
* * *n.sound waves of extremely high frequency (above 20,000 Hz), inaudible to the human ear. Ultrasound, usually in the range 2-20 MHz, can be used to produce images of the interior of the human body, in the same way that X-rays can be used to build up pictures, but with the advantages that the patient is not submitted to potentially harmful ionizing radiation and that structures not opaque to X-rays can be seen (see ultrasonography). The vibratory effect of ultrasound can also be used to break up stones in the kidney or elsewhere (see lithotripsy) and in the treatment of rheumatic conditions and cataract (see phacoemulsification). Ultrasonic instruments are used in dentistry to remove calculus from the surfaces of teeth and to remove debris from the root canals of teeth in root canal treatment.
* * *ul·tra·sound (ulґtrə-sound) 1. sound waves with a frequency above the range of human hearing (greater than 20,000 Hz); see ultrasonics. 2. ultrasonography.
Medical dictionary. 2011.