Visual Grading Assessment of Quantitative Transmission Ultrasound Compared to Digital X-ray Mammography and Hand-held Ultrasound in Identifying Ten Breast Anatomical Structures

Transmission Ultrasound is an imaging modality based on tomographic techniques extended to ultrasound. We have performed 2 paired-reader, paired-subject evaluation visual grading analysis studies comparing transmission ultrasound, digital x-ray mammography and hand-held ultrasound when visualizing ten normal breast anatomic structures. To compare the image quality of the three modalities, multiple readers scored the image quality of transmission ultrasound compared to the other two modalities using an ordinal rating scale. The proportion of breasts where the image quality was rated better on transmission ultrasound was reported for each feature including different ACR BI-RADS® breast density classes. Using x-ray mammography as a comparator, readers scored transmission ultrasound images as equivalent or better in more than 90% of breasts. Using hand-held ultrasound as a comparator, readers scored transmission ultrasound images as equivalent or better in more than 80% of breasts. In the analysis by breast density, there was no significant change in the performance by transmission ultrasound for any density subtype. This study confirms that transmission ultrasound can adequately see all the major anatomical features of the human breast that can be seen by no other routinely used clinical imaging method, including accurately visualizing ductal and glandular tissue detail, even in dense breasts.