Novel Ultrasonic Imaging Method for Remote Palpaton of Breast Tissues

摘要

A method of Remote Palpation, which may allow the detection of small, stiff lesions lying deep within the breast is under investigation. In this method, acoustic radiation force applied to localized (approximately 2 mm3) regions of tissue, and the resulting tissue displacements are mapped using ultrasonic correlation based methods. An area that is stiffer than the surrounding medium distributes the force, resulting in larger regions of displacement, and smaller maximum displacements. The resulting displacement maps may be used to image tissue stiffness. We have developed a finite element model of Remote Palpation, with which a parametric analysis of the affect of varying tissue and acoustic beam characteristics on radiation force induced tissue displacements has been performed. We have developed phantom tissue fabrication facilities, with which models of tissue of varying stiffness and acoustic absorption characteristics have been built. Experimental pulse sequences have been developed for our Elegra scanner, with which initial experiments have been performed in phantoms. The tissue displacement patterns observed in the experiments are consistent with those predicted by the simulations. Peak displacements of 30 microns were observed in a phantom with a Young's modulus of 0.8 kPa. These initial results suggest considerable clinical potential for Remote Palpation.