Three-dimensional thermoacoustic imaging for early breast cancer detection

Purpose: Microwave-induced thermoacoustic tomography (TAT) is a noninvasive modality based on the differences in microwave absorption of various biological tissues. In this paper, the feasibility of the early breast tumor detection by TAT system has been discussed and validated experimentally. Methods: A fast TAT system, which based on three 128-elements transducers, a 384-64ch switch and a parallel data acquisition system (DAS), was developed to reconstruct the three-dimensional (3D) image of a breast model with similar microwave absorption coefficient to breast tissue. A novel method to explore the ability of TAT system to distinguish absorption coefficient was introduced and the minimum absorption coefficient difference that can be distinguished clearly by our TAT system is 12 m(-1). Results: The potential applications of the TAT system were clearly demonstrated by successfully mapping breast model with mimicked tumors and microcalcification. An imaging experiment of human breast tumor embedding in the breast model was performed and the tumor was visualized by the 3D thermoacoustic volume. Conclusions: The thermoacoustic images match well with the samples and achieve penetration depth of 6 cm. The experimental results indicate that TAT has a great potential to be used for detecting early-stage breast cancers with high contrast and high resolution. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4757923]