What is digital breast tomosynthesis (DBT)?

Breast tomosynthesis is the first and only 3D digital technology that enables radiologists to see your breast in greater detail than traditional mammography. Approved by the U.S. Food and Drug-Administration (FDA), breast tomosynthesis produces a 3D image of your breast tissue in one-millimeter slices, allowing radiologists to see “inside” the breast, minimizing or eliminating ambiguity caused by overlapping tissue, common in women with dense breasts. Among its many benefits, it offers a 35% increase in cancer detection rate.

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The digital breast tomosynthesis (DBT) system employs a digital X-ray that records a series of low-dose, high-resolution images of the breast while traversing a small (15°) arc around the compressed breast. As the projection angle changes, images are recorded at slightly different depths and thicknesses, from one surface of the breast to the other.

The compression time of approximately four seconds needed for DBT is similar to that used for standard two-dimensional digital mammography. Following the procedure, reconstruction algorithms are used to create a 3-D rendering of the interior breast architecture.

This rendering is presented to the breast imager as a stack of images of the breast that, in total, represent the area from one skin surface to the other. Each DBT image can be magnified or manipulated to better reveal minute detail. These processes can reduce the superimposition of overlapping tissue shadows seen in two-dimensional mammograms, allowing more accurate interpretations of breast changes.

Among the greatest advantages of DBT for radiologists is that it offers images with a clarity and degree of detail substantial enough to reduce some of the false-positives and false-negatives associated with 2-D mammographic imaging. In small series studies, researchers have reported reducing the false-positive callback rate by as much as 30 to 40%.

Dr. Anne C. Hoyt, MD
Diagnostic Radiologist

Digital breast tomosynthesis (3D mammography), is a U.S. Food and Drug Administration (FDA)-approved procedure that is given just like a regular mammogram—the difference is the number of images. When the breast is compressed,15 very low-dose exposures at different angles are obtained as the x-ray tube moves in a small arc over the top of the breast. This information is then fed to a computer where it’s processed and reconstructed into three-dimensional images.

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