Computational Feasibility Study of Contrast-Enhanced Thermoacoustic Imaging for Breast Cancer Detection Using Realistic Numerical Breast Phantoms

The feasibility of contrast-enhanced thermoacoustic imaging (CETAI) for breast cancer detection is investigated by a systematic computational study using realistic numerical breast phantoms with tumors. Single-walled carbon nanotubes with a nontoxic concentration are applied as the contrast agents to increase the dielectric properties of the breast tumors and enhance their detectability. Complete CETAI models are developed and solved for generated thermoacoustic signals by numerical techniques. Back-projection imaging and differential imaging are performed to visualize the tumors. It is shown that the location, shape, and dimension of the tumors in different breast phantoms are all reliably reconstructed in the obtained differential images, irrespective of the different breast densities. Moreover, several important aspects such as safety issues, signal-to-noise ratio, scan time, figures of merit of the image quality, and spatial resolution of the images are quantitatively studied to explore the feasibility of CETAI for possible clinical applications. The simulation result is verified by another independent numerical method and a preliminary experiment is performed to demonstrate the major point of the CETAI strategy. The presented results bolster the applications of CETAI as a potentially safe, possibly rapid, accurate, high-resolution, and breast-density-insensitive technology for 3-D breast cancer detection.