New Methods for Quantitative, High-Resolution Ultrasonic Imaging of the Breast

摘要

The objective of this research is to form quantitative, high-resolutionultrasonic images of the breast using advances in adaptive focussing, a breakthrough in inverse scattering, and unique experimental apparatus. Two new imaging methods were implemented and test images were formed to demonstrate the potential of the methods to improve resolution for better diagnosis of breast cancer. One method employs adaptive focussing to compensate for aberration in pulse-echo imaging. In this new technique, transmit signals are synthesized from scattered signals by using backpropagation followed by time-shift estimation and compensation. The other method uses eigenfunctions and eigenvalues of an operator associated with scattering measurements. to focus adaptively on distributed scattering objects and to form quantitative images efficiently. Image evaluation employed comparison with observed morphology of scattering objects as well as with conventional b-scan images and reconstructed x-ray images.