A Force-Matched Approach to Large-Strain Nonlinearity in Elasticity Imaging for Breast Lesion Characterization.

Area of Science:

• Biomedical Ultrasound
• Medical Imaging
• Biophysics

Background:

• Ultrasound elasticity imaging is crucial for detecting breast cancer.
• Traditional methods assume linear elasticity, but soft tissues exhibit nonlinear behavior at large strains.
• Understanding nonlinear elasticity is key for accurate malignancy characterization.

Purpose of the Study:

• To evaluate the nonlinear elastic response of breast lesions for malignancy characterization.
• To utilize force measurement and controlled compression during ultrasound imaging.
• To assess the potential of nonlinear ultrasound techniques for improved breast lesion diagnosis.

Main Methods:

• Recruited 54 patients for the study.
• Employed a custom force-instrumented compression device for controlled force application during ultrasound.
• Matched motion-tracking derived strain with compression force for analysis using curve fitting.

Main Results:

• Significant differences in lesion elasticity were observed at higher compressional forces (2-6N).
• A power law function provided the best fit for force-matched strain data.
• A statistically significant difference in the power function's scaling parameter distinguished malignant from benign lesions (p=0.025).

Conclusions:

• Greater separation between malignant and benign lesion strain was achieved at high compression forces.
• A power law model effectively characterized nonlinear elastic effects in breast lesions.
• This nonlinear model successfully differentiated malignant from benign breast lesions.