E1548. A Brief History of the Evolution of Breast Ultrasound
  1. Rachel Kaplan; Medstar Georgetown University Hospital Department of Radiology
  2. Erini Makariou; Medstar Georgetown University Hospital Department of Radiology
  3. Erin Crane; Medstar Georgetown University Hospital Department of Radiology
Breast ultrasound (US) has become an indispensable tool for imaging the breast. The technology has a notable history, which has relevance to all radiology trainees and practicing physicians.

Educational Goals / Teaching Points
The goal of this exhibit is to describe the major advancements in technologies important to the field of breast US.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
High frequency US technology found its way from military applications to breast imaging in the early 1950s. Acoustic characteristics of breast tumors in the in vivo breast measured by A-mode high frequency sonogram were first reported by Wild and Neal in 1951. A year later, Wild and Reid published the first B-mode sonograms of human breast tissue. This work was foundational to the first clinical application of breast US, also by Wild and Reid in 1954, where lesions were correctly preoperatively characterized as benign and malignant. In the 1950s and 60s, transducer designs were introduced with lower frequencies, multiple crystal emitting and receiving arrays, and focusing elements, which produced higher quality images. In 1969, a notable improvement was achieved by Jellins and Kossoff with the advent of grayscale imaging. During the same period, E. Kelly Fry and colleagues developed an online computer-controlled system and changed their focus from characterization of tissue to detection of asymptomatic subclinical lesions and led the first effort to correlate sonographic patterns with histopathologic findings. Based on the pioneering work of Wells and colleagues in the 1960s, prone scanning technique was incorporated into many models of scanners across the globe in the late 1970s. Digital technology brought improvements in resolution from beam shaping and signal processing in the early 1980s. During this same time period, doppler signals’ utility in breast imaging was established. In 1993, the sonographically guided automated core biopsy was first described. The early 1990s also brought the advent of digital beam formers and broad-bandwidth capabilities, which allowed the development of spatial compounding and tissue harmonics, both of which were later applied to clinical breast imaging in the early 2000s. In 2003, the first edition of the Breast Imaging Reporting and Data System (BI-RADS) atlas for US was published. Throughout the 2010s to today, US continued to gain acceptance as an adjunctive screening tool. Automated breast US was approved by the U.S. Food and Drug Administration (FDA) in 2012. In the same year, it was demonstrated that adding shear wave elastography to B-mode BI-RADs feature analysis improved specificity of breast mass assessment without loss of sensitivity. A 3D whole breast ultrasound system was approved by the FDA in 2021 as an adjunct to mammography for screening in patients with dense breast tissue. Most recently, a wearable artificial intelligence powered whole-breast US system, ATUSA, was cleared by the FDA in May 2022.

Ultrasound has proven itself to be of great utility in breast imaging, and advances in technology have improved its usefulness, from tissue characterization to diagnostic adjunct, to screening adjunct.