Ultrasonic viscoelasticity imaging of nonpalpable breast lesions.

The prognosis of breast cancer patients improves with early and accurate diagnosis. A small clinical study was conducted with 21 women having a single nonpalpable breast lesion, each detected mammographically with later pathology confirmation. Elasticity images were acquired on each patient to test for the ability to differentiating malignant and benign lesions. The mechanical relaxation time T(1) images showed a tissue-specific T(1) contrast that is negative for all 11 malignant lesions and positive for all 10 benign lesions. Strain images were estimated using a regularized multi-scale optical flow (ROF) algorithm. Adjustments to the input parameters to the ROF and their subsequent effects on T(1) estimation and computation time are shown to have a strong effect of diagnostic performance.