For many years, ultrasound has had a defined and very limited role in breast evaluations, being used for neither diagnosis nor detection. The reasons were bundled together in the phrase “operator dependence.” Factors contributing to the operator dependence included small, 5-cm² field-of-view; acoustic speckle and a coarse, noisy image; poor, inconsistent scanning technique; inexperience with ultrasound depiction of breast anatomy and pathology; no standard for lesion analysis and reporting until publication of BI-RADS for ultrasound;1 and diagnostic use limited to cyst versus solid mass.2
The specificity and sensitivity of breast ultrasound were regarded as inadequate for differentiating benign from malignant solid masses and for detection of cancers not palpable or identifiable on mammograms. Since the FDA gave premarket approval to the L10-5 linear broadband-width transducer for distinguishing benign from malignant etiologies in 1996,3 now nearly 15 years ago, technical advances have permitted use of ultrasound for many new applications. More important is the increasing confidence in breast diagnoses made using this modality, whose technical advances have been striking.
Nevertheless, the specificity issue remains, and although standardization of lesion assessment through BI-RADS feature analysis has supplied three morphologic features that, taken together, suggest a benign etiology—oval shape, circumscribed margin, and orientation parallel to the skin—masses with these features are still frequently biopsied; their histopathologies are found to be benign, as expected. Like the perpetual hunt for the Fountain of Youth, a dependable talisman has been the object of this specificity quest.