Fine elasticity imaging utilizing the refined iterative rf-echo phase matching algorithm

Abstract

It is quite remarkable that the pathological state of living soft tissue highly correlates with quasi-static mechanical properties, i.e., particularly elasticity. With such a fact in mind, we previously developed "the iterative 2D rf-echo phase matching method" that determines the 2D displacement vector field generated in in vivo soft tissue during acquisition of two successive rf-echo data frames. That is, since this displacement measurement allows an accurate estimate of the resultant strain distributions to be obtained, we can stably quantify the tissue elasticity by determining the relative shear modulus distribution. Toward the finer elasticity imaging, we recently improved the previous displacement measurement method such that better phase matching can be realized. That is, we novelly incorporate an effective mechanism into the previous one: the local region size is made suitably smaller during the iterative phase matching. This leads to improvement of the quality of the finally obtained elasticity image. The effectiveness was verified through simulation, and an experiment on in vitro pork and in vivo breast tissues.