Elastography

Elastography is a non-invasive method in which stiffness or strain images of soft tissue are used to detect or classify tumors. A tumor or a suspicious cancerous growth is normally 5-28 times stiffer than the background of normal soft tissue. When a mechanical compression or vibration is applied, the tumor deforms less than the surrounding tissue. i.e. the strain in the tumor is less than the surrounding tissue. Hence a strain image may, under particular simplifying assumptions, be interpreted as representative of the underlying Young's modulus distribution. The strain distribution may be temporally variant in the presence of internal fluid flow. Elastograms (images of tissue strain) have been shown to be affected by the degree of adherence of the tumor to its surroundings, indicating a potential to extend elastography to tumor mobility characterisation to improve diagnostic accuracy and surgical guidance.