Patent ID: 9554777
Date: 2017-01-31
CPC Classifications: A61B,G01N

Claim:
1. A method of evaluating tissue stiffness of a target area, comprising: positioning an ultrasound elasticity imaging apparatus adjacent a surface of an area of tissue where the target area is located; applying a first amount of force to the area of the tissue to be evaluated to provide a first amount of applied strain on the target area; increasing the force on the strained tissue until a second amount of force is applied, the second amount of force providing a second amount of applied strain on the target area; directing a plurality of ultrasound beams at the tissue and acquiring a plurality of ultrasound echoes from the strained tissue in the target area to calculate an amount of developed strain within the target area, the amount of developed strain being calculated at a plurality of points across a strain range between the first amount of applied strain and the second amount of applied strain; and determining a shear wave velocity at a plurality of locations in the target area and comparing the applied strain to the determined shear wave velocities to evaluate a tissue stiffness of the target area, wherein the tissue stiffness is determined by the relationship between the determined shear wave velocities and the amount of applied strain, and the tissue stiffness is used to identify a condition of the target area being evaluated based on a numerical, nonlinear parameter that is extracted from the relationship between the developed strain and the applied strain.