Experimental Evaluation of Composite Tissue-Type Ultrasound and Microwave Imaging

The recently proposed concept of composite tissue-type image (cTTI), which provides an easy-to-interpret image constructed from quantitative ultrasonic and electromagnetic properties, is experimentally investigated. The experimental data set used for the ultrasound investigation is obtained from the multimodal ultrasound breast imaging system. The experimental data set utilized for microwave imaging is provided by an inhouse system at the University of Manitoba. To this end, a tissue mimicking phantom and a human forearm are utilized for experimental ultrasound and microwave imaging. In addition, the cTTI algorithm is modified to take into account differences in the quantitative accuracy of reconstructing one property compared to other properties so as to increase the achievable accuracy in the resulting cTTI. In addition to experimental ultrasound and microwave data, the cTTI method is also applied against synthetic data obtained from an MRI-based numerical breast phantom to further demonstrate the performance of the cTTI not only with respect to microwave and ultrasound tomography data but also with respect to their combination. Finally, the improvements of the cTTI reconstructions based on changing the prior probabilities compared with equal prior probability distribution are shown for combined ultrasound and microwave tomography of a numerical breast phantom.