Also found in: Dictionary, Thesaurus, Encyclopedia.
a manifestation of increased echo amplitude returning from regions beyond an object, such as a fluid-filled cyst, which causes little or no attenuation of the ultrasound beam. Compare: acoustic shadow.
relating to sound or hearing.
used in the low speed transmission of data over a telephone line.
an artifact seen in ultrasound examination. There is an area of increased brightness underneath fluid resulting from the lack of impedance when sound waves pass through fluid and increased echoes from underlying structures.
see vestibulocochlear. See also Table 14.
acoustic reflex test
used primarily in humans to differentiate between sensorineural and conductive hearing loss.
an artifact seen in ultrasound imaging in which an intensely echogenic line appears at the surface of structures which block the passage of sound waves.
the body surface area selected for application of the ultrasound transducer, through which sound waves will be transmitted. Consideration must be given to underlying bone or gas-filled structures which would impair image quality.