FUNDAMENTAL LIMITATIONS ON THE CONTRAST-TRANSFER EFFICIENCY IN ELASTOGRAPHY - AN ANALYTIC STUDY

Elastography is a new ultrasonic imaging technique introduced to produ ce images of the Young's modulus distribution of compliant tissue, Thi s Young's modulus distribution is derived from the ultrasonically esti mated longitudinal internal strains induced by an external compression of the tissue, The displayed two-dimensional images are called elasto grams, Recently, contrast-transfer efficiency, defined as the ratio of elasticity contrast as measured from elastogram to the true contrast, was used to illustrate by simulation the fundamental limitation of el astography in displaying the elastic modulus contrast of soft inclusio n in a hard background and vice versa, In this paper, using a classica l analytic solution of the elasticity equations derived for an infinit e medium subjected to a uniaxial compression, we confirm such earlier simulations results, For this purpose we derive an analytic expression predicting the observed contrast in elastograms.