FAQ About Digital Breast Tomosynthesis (3D Mammography)
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: July 23, 2014
What is breast tomosynthesis?
Breast tomosynthesis, or 3D mammography, is a technique using xrays to produce a three dimensional picture of the breast. It results in the production of slices through the breast which can be viewed as individual pictures. This often clarifies whether a finding is a true abnormality or an overlap of normal structures, and can result in the visualization of abnormalities that would be hard or impossible to see otherwise. Standard, or 2D mammograms, consist of one picture of the breast in each position, as opposed to many slices. Overlapping breast tissue can make the 2D images difficult to interpret.
How are the 3D images obtained?
The 2D and 3D images for each view of the breast are obtained during a single breast compression. To obtain the 3D images, the xray beam swings in an arc, usually after the standard 2D views are obtained. Or, with the newest technology, the 2D images can be reconstructed from the tomosynthesis 3D images, decreasing the xray dose. Compression will last for just a few seconds longer than for a standard mammogram without tomosynthesis, but most patients will likely not notice a difference.
Who should get breast tomosynthesis?
Everyone who is a candidate for 2D mammography is also a candidate for tomosynthesis. Patients with dense breast tissue may benefit more from the added modality than those with more fatty breast tissue, but even fatty breasts are better evaluated with tomosynthesis.
What about radiation exposure?
With studies where 2D images are reconstructed from the tomosynthesis images, the xray dose from the whole (2D and 3D) study is exactly the same as from a 2D-only study. Even for studies where the 2D and 3D images are both obtained, the total dose is still below the limit under the Mammography Quality Standards Act (MQSA) set forth by the FDA.
How do I get a 3D mammogram?
The referring clinician can order it, or the patient can request it at the time of the study.
Will patients be charged?
There is no additional charge to the patient.
What improvements does 3D mammography make over 2D?
A research study found that tomosynthesis imaging, or 3D mammography, finds significantly more invasive cancers than a traditional, 2D mammogram. Invasive cancers are more likely to spread or cause death. 3D mammography also reduces the number of women called back for unnecessary screenings due to false alarms which reduces anxiety, as well as health care costs.
Specific improvements with 3D mammography screening found in the research:
- A 41% increase in the detection of invasive breast cancers
- A 29% increase in the detection of all breast cancers
- A 15% decrease in women recalled for additional imaging