Ultrasonic speckle motion inherent to tissue motion: theory and simulation

An echographic image-formation model is developed to evaluate the relationship between the ultrasonic speckle motion and the underlying tissue motion. The model is divided into an instrumental part and a dynamic tissular component. Using this model, a simulation study of the correlation between various linear transformations of the tissue and the corresponding ultrasonic speckle motions is performed. It shows simulated speckle motions closely linked to the tissue dynamics when motions of low amplitude are considered. In addition, a theoretical analysis is presented based on a 2-D extension of the envelope crosscorrelation analysis of a narrowband Gaussian noise. This sets the ground for the development of an ultrasonic strain gauge particularly useful for the assessment of biomechanical soft-tissue properties