Quantifying the impact of breast density on the lag-one coherence of hypoechoic masses

Ultrasound imaging is often used as a diagnostic tool to supplement mammography particularly in patients with dense breast tissue, because the ability of a mammogram to detect cancer is significantly lower in these patients. However, when breast tissue is dense, interactions between tissue layers can result in acoustic clutter in the ultrasound image, obscuring masses of interest and resulting in more false positives with increasing breast density. This work investigates the impact of breast density on a quantitative coherence-based metric, lag-one coherence (LOC). Greater separability was seen between fluid and solid masses within dense breast tissue compared to nondense breast tissue. Specifically, the sensitivity and specificity for fluid-filled mass detection in non-dense breast tissue were 0.768 and 0.688, respectively, which improved to 0.911 and 0.898, respectively for masses within dense breast tissue. These insights support deployment of LOC as a quantitative differentiation tool, particularly for patients with dense breasts who are most commonly referred for ultrasound exams resulting in unnecessary biopsies due to the presence of acoustic clutter.