ABSTRACT
The term ‘elastography’ is used to describe techniques which provide information related to the stiffness of tissues. It has long been known that diseased tissues such as tumours are stiffer than the surrounding normal tissue. Indeed one of the oldest diagnostic methods is the assessment of the stiffness of tissues by palpation; if a stiff lump is found then the lump may well be diseased. When a material is subject to a force it is stretched or compressed. The general terminology and principles used to describe this process can be illustrated using a simple material such as a rubber band or a wire. If a weight is attached to a strip of the material, the strip stretches. If the weight is increased the strip stretches further. In the research literature there are several methods for elastography based on measuring the change in tissue dimensions arising from an applied force.
