Conventional digital mammography (2DM) is the most commonly procedure employed for mammographic screening. It creates two dimensional (2D) mammogram images using X-rays. However, one drawback of the technology is it shows all tissue composing the breast in one image. If a woman has dense breast tissue, which appears white, cancer also appears white and can be hidden within the areas of high fibroglandular density.
Digital breast tomosynthesis (DBT) mammography, also called 3D mammography, takes multiple X-ray pictures of the compressed breast using different projection angles as the X-ray head moves in an arc around the breast.This data is used to reconstruct multiple, stacked thin images that represent layers of breast tissue. 3D Breast tomosynthesis is able to peel away layers of dense breast tissue, providing a clearer visualization of cancers and making it easier to identify dense tissue and suspect lesions. This enables the radiologist to identify small or hidden lesions that otherwise would not appear on a conventional 2D mammography.
Some of 3D mammography’s advantages include: better asymmetry assessment; better definition of tumor size and its borders; detection of architectural distortions; evaluation of dense breasts and lesion contour; increase in cancer detection rates (8 cases per 1,000 studies in 3D mammography, against 6.1 cases per 1,000 studies in conventional digital mammography).
The U.S. Food and Drug Administration (FDA) has cleared several breast tomosynthesis imaging systems since 2011.
• Hologic Selenia Dimensions, 2011
• Siemens Mammomat Inspiration Prime with Tomosynthesis Option, 2015
• GE Healthcare Senographe Pristina, 2016
• Hologic 3Dimensions, 2017
• Fujifilm Aspire Cristalle, 2017
According to the FDA Mammography Quality Standards Act (MQSA) statistics, nearly half of the certified facilities now offer digital breast tomosynthesis. Of the 18,640 accredited mammography imaging units in the U.S., 5,791 are now DBT machines (as of April 2018), and that number continues to grow as the technology begins to replace older 2D mammography systems.
Here are some related articles and videos on 3-D mammography: