Verification of the feasibility of elasticity tomography-simulation study

Abstract

The pathological state of living soft tissue highly correlates with quasi-static mechanical properties, particularly, elasticity. With such consideration in mind, the authors previously developed the iterative 2D ultrasonic RF-echo phase matching method that allowed providing them the considerably accurate estimates of 2D strain distributions generated in vivo in soft tissues by heart motion/extracorporeally applied pressures or very low frequency vibrations. Furthermore, the authors proposed a novel inverse problem that determined a relative shear modulus distribution with respect to reference shear moduli only from measured strain distributions under the assumption that no mechanical source exists in the ROI. However, as previously demonstrated, due to the combination of noise in measurement data and improper configurations of mechanical sources/reference regions, the problem is inevitably ill-conditioned in real-world applications. Thus, to uniquely determine the acceptable approximation to the original target distribution despite their occurrence, the authors developed a robust reconstruction method in conjunction with a so-called regularization method. To verify the feasibility of a whole technique, i.e., elasticity tomography, reconstruction is carried out using RF-echo data simulated on a simple soft tissue model.