Quantitative sonography.

Abstract

The review presents a perspective on ultrasonic techniques which place numerical values on properties of tissue or physiological function. Two distinct approaches to tissue characterisation are identified and the various techniques employed are reviewed. The range of Doppler techniques currently in use or under development are described. The potential roles of the various techniques are discussed, using clinical results from the Ultrasonics Institute as a basis. Attenuation measurements show a considerable spread in results, but sound speed appears to correlate closely with the degree of fibrosis in liver and spleen. Other methods have been found useful in specialised areas. The use of pulsed Doppler with a resolution cell sufficiently large to encompass the entire vessel, in conjunction with B-mode imaging to determine geometry, permits volumetric flow measurements to be made in deep vessels and reveals previously inaccessible physiological data. The use of analysis techniques to provide quantitative information in the physiological state or function of tissue promises to add a new dimension to diagnostic ultrasound.