Inverse imaging of the breast using the conjugate gradient-bivariate material classification technique

Presents the bivariate material classification (BMC) technique for ultrasound imaging of the breast. The BMC technique is used in conjunction with the conjugate gradient (CG) method to solve the inverse problem. Results are shown for a one-quarter scale, 2D model of the breast. It is found that the CG-BMC technique increases convergence and, in addition, gives more accurate results. Approximately 30% fewer iterations are required, significantly reducing the computational cost. The CG-BMC algorithm appears to be robust to noise, achieving good results for a signal-to-noise ratio of 50 dB