Ultrasonic tomography of biological tissue.

In this paper, quantitative tomographic reconstructions of biological tissue are presented. First, the experimental setup and a hybrid filtered backpropagation (FBP) technique are briefly described. Using this technique, which includes exact backpropagation of data prior to reconstruction by means of the classical FBP algorithm, quantitative velocity maps of relatively large biological objects can be obtained. Since the FBP algorithm is based on a first-order scattering approximation, the deteriorating effects of higher-order scattering in diffraction tomography are also discussed. The higher-order scattering limits the size of the biological object to a few centimeters.