Journal of Ultrasound in Medicine, Vol 11, Issue 8 387-392, Copyright © 1992 by American Institute of Ultrasound in Medicine
Sonoelasticity of organs: shear waves ring a bell
K. J. Parker and R. M. Lerner
Rochester Center for Biomedical Ultrasound, University of Rochester, New York 14627.
Sonoelasticity is the use of ultrasonography to visualize, in real time,
the hardness of stiffness of tissues and organs by depicting the tissue's
motion in response to an applied vibration source. The applied vibration
source is usually of low amplitude and low frequency (less than 0.1 mm
displacement and less than 2000 Hz). Under these conditions, the natural
vibration response of tissues and whole organs is revealed as a standing
wave pattern determined by the low-frequency elastic constants of the
tissues and their boundary conditions, factors that are not related to the
ultrasonic echogenicity. As a result, hard or dense isoechoic tumors that
are undetectable by conventional ultrasonography often can be visualized in
sonoelasticity imaging by virtue of their altered vibration response. In
this report, we demonstrate the appearance of organs such as the breast,
liver, and kidney during real-time, in vivo sonoelasticity imaging. The
results show that the shape and location of vibration patterns are
dependent on the tissues and vibration frequencies; thus, information about
the basic elastic properties of tissues should be obtainable.
