摘要：AbstractCancerous tumors exhibit significantly higher stiffness than healthy breast tissues. a hysteresis loop analysis method is used to identify the nominal elastic stiffness in different horizontal directions for breast cancer diagnosis in a Digital Imaging Elasto-tomography (DIET) screening system. The sensitivity of the method to measurement errors from the DIET system is first evaluated using a homogeneous healthy phantom with different camera angles. The identification method is then validated against 4 phantoms with stiffer inclusions of 10-20mm diameter over a range of actuation frequencies. Results show displacement reconstruction errors from very small motion can be eliminated by using a threshold ∆d to significantly reduce errors in identified nominal elastane. The stiffer inclusion induced a greater number of reference points with higher stiffness in the inclusion segment than other segments in x and y directions. The presence of a stiffer “tumor” inclusion is detected by comparing the nominal stiffness to an automatically defined threshold, kt. Inclusion segments can then be localized using an inclusion indicator, Kindex. The overall results validate the method is capable of providing robust estimations of nominal stiffness over a realistic range of actuation frequencies, and inclusion sizes and angle for the DIET concept.
