Strain Imaging of the Breast by Compression Microwave Imaging

A method that uses microwave pulses to achieve strain imaging of the breast is presented. In the proposed method, the breast is inserted in an enclosure that defines the boundary conditions for the breast deformation under the influence of external pressure. The upper plate of the enclosure, which also includes an antenna array, is attached to a compression tool, whereas the lower and the front plates are fixed. The breast is allowed to extend in the lateral direction when pressed by the top plate. Each of the antennas at the top plate is used to send an ultrawideband pulse to penetrate the breast and measure the backscattered pulse. Two sets of measurements are taken: one pre- and another post-compression of the breast. A sliding window of cross correlation is then performed on the two sets of data to establish the time delay of each segment of the scattered pulse due to compression. That time delay is then employed to get a three-dimensional strain image of the breast. As lesion tissue is typically much stiffer than normal breast tissue, then regions of low or zero strain indicate areas in need of further diagnostic checks. Full-wave simulations are used to validate the presented imaging method.