Acoustic contrast enhancement: value of several system gain variations in gray scale ultrasonography.

Because of the broad spectrum of echogenicity inherent in the heterogeneous composition of the abdominal viscera, system gain variations may be useful in gray scale ultrasound imaging to improve lesion definition. In general, Anechoic or hypoechoic processes may be accentuated by scanning in the higher gain ranges, while hyperechoic lesions may be better delineated at lower gain levels. Thus adjustments in "acoustic contrast" may supplement and reinforce information derived from an initial standard medium gain scan. Although the liver serves as a model in this report, careful selection of a variety of system gain levels can be helpful in evaluating focal lesions in any organ.