Dynamical Imaging of Physiological Motion in Liver Tissue by Using Complex Correlation Method between Successive Echo Frames

The 2-dimensional (2-D) ultrasonic imaging of static strain or elasticity in soft tissues with quantitative images of distributed parameters has been developed for medical diagnosis. However it is very hard to realize the quantitative image of stationary elastic parameters because living tissues are always affected by dynamical pressure change under the pulsatile blood circulation. Thus to replace the static image dynamically limited to local tissue substances the straightforward, physiological dynamic image of slight local motion during a frame interval, which cannot be visualized in conventional B-mode images, was pursued in this study. In the overall performance analysis of estimated axial displacement on accuracy, variance and spatial resolution, physiological dynamic images, which recorded velocity and acceleration between successive echo frames, were demonstrated by using real-time clinical data acquired from hepatohemangeoma. These images proved that real-time imaging is a practical and promising approach toward achieving an advanced version of clinical palpation, ultrasonic visualized palpation.