Simultaneous elastic image registration and elastic modulus reconstruction

Ultrasound elastography, the imaging of soft tissues based on shear elastic modulus, is a growing imaging method. The technique relies on being able to image soft tissue while it is being deformed by a set of externally applied forces. Typically, block matching methods are used to obtain a dense estimate of the point-to-point displacement field in the field of view. This displacement field can then be used as input to an inverse problem to reconstruct the elastic modulus distribution. We describe several advantages of combining these steps into one, and show a practical methods to do so. In essence, we show how to regularize a nonrigid elastic registration problem via an unknown elastic modulus distribution.