ABSTRACT
Elasticity imaging (or elastography) is a general name for a group of diagnostic methods capable of remote evaluation of tissue mechanical properties. Biochemical, molecular, cellular, and functional (i.e., microscopic) changes in biological tissues leading to pathologies (e.g., breast cancer) o¬en result in macroscopic changes in tissue properties, such as tissue elasticity, viscosity, and other mechanical attributes of tissue. ™e fact that many pathologies manifest themselves as changes in sti›ness serves as the fundamental basis for diagnostic elasticity imaging. From ancient times to the present, physicians have used palpation as a diagnostic tool to detect breast cancer because tumors are generally sti›er than normal tissue. ™us, manual palpation can be considered the oldest form of elastography. In the case of manual palpation, many of the components necessary for modern elasticity imaging are present. First of all, a physician compresses the breast to introduce deformation and stress in the tissue. ™e physician’s œngers are then used as a sensitive tool to assess the mechanical response of the underlying tissue to this external excitation. Finally, based on his or her experience, the physician makes a conclusion about the presence of pathologies and their properties. ™e sensitivity of the physician’s œngers, however, is limited and small lesions or lesions that lie deep within the breast are di–cult to palpate. In addition, palpation is not objective and provides only qualitative-not quantitativeinformation. To this end, elasticity imaging technologies o›er an improvement over palpation in detecting and di›erentiating tumors. ™ey promise to provide objective and quantitative information that is operator independent.
