Digital Breast Tomosynthesis (also known as 3D mammography) was approved by the FDA in February 2011. It is a modification of the current 2D (digital) mammography that, instead, produces a 3D image of the breast.
Tomosynthesis creates multiple images or "slices" that step through the breast tissue. This allows the radiologist to see greater detail and helps reduce the impact of overlapping breast tissue. The process is performed at the same time as a normal mammogram, on the same scanner, with no noticeable differences in the experience or time expended for the patient.
Reduced Callbacks: Tomosynthesis allows radiologists to look at different layers of the breast tissue, helping to distinguish normal breast tissue from abnormal breast tissue. Information from these additional views is believed to lead to fewer callbacks and, therefore, less anxiety for women.
Better Visualization: Radiologists can better determine the size, shape and location of an abnormality with tomosynthesis.
Improved Sensitivity: By minimizing the impact of overlapping breast tissue, tomosynthesis may improve breast cancer screening and early detection.
From a patient's point of view: A 3D mammogram exam is very similar to a 2D mammogram—both are performed together on the same scanner. Just as with a digital mammogram, the technologist will position you, compress your breast under a paddle, and take images from different angles.
During the 3D portion of the exam, the x-ray arm of the machine makes a quick arc over the breast, taking a series of breast images at a number of angles. The entire procedure should take approximately the same amount of time as a 2D mammogram.
From a technical point of view: The technologist sends your breast images electronically to the radiologist, who will examine breast tissue one layer at a time instead of viewing all the complexities of your breast tissue in a flat image. Fine details can be more clearly visible, less likely to be hidden by the tissue above and below.
This image depicts a tomosynthesis experience from the patient's point of view. A 3D mammogram exam is very similar to a 2D mammogram. In fact, both images are taken at the same time, on the same scanner. And just as with a 2D digital mammogram, the technologist positions the patient, compresses their breast under a paddle and takes images from different angles. During the 3D portion of the exam, the machine's x-ray arm makes a quick arc over the breast, taking a series of images at a number of angles. Tomosynthesis adds no time to the exam, with the entire procedure taking approximately the same amount of time as that of a 2D mammogram.
This image illustrates the differences in 2D and 3D breast imaging. In the "conventional" 2D mammogram (pictured left), there is an apparent area of concern that may require additional studies, like another mammogram or a biopsy. Instead, looking at the same breast tissue in a succession of 3D images (pictured right), doctors can now see that the tissue is, in fact, normal breast tissue that was simply overlapping in the traditional mammogram, thus creating the illusion of an abnormality. In this scenario, the patient likely avoided a callback for an additional mammogram—and the anxiety that goes along with it—thanks to tomosynthesis technology.
All women may benefit from tomosynthesis; however, the benefit is greatest in women with dense breast tissue, because it can mask cancers and/or lead to false positives.
How do you know if you have dense breasts?
Density refers to breasts with more glandular and connective tissue than fat—not breast firmness—so a mammogram is the only way to find out about density. You can either:
- Speak with your physician. If you have had a prior mammogram, your primary care provider will have a report on record that would indicate your breast density, or
- Speak with your mammography provider. If you have had a prior mammogram, your mammography provider will have a report on record that would indicate your breast density.
Tomosynthesis is an optional service for the patient, which supplements the conventional mammographic images. While 2D digital mammography remains the gold standard for early detection 3D images can offer better visualization for radiologists who are helping certain groups of patients—particularly those with dense breasts, which is determined by a prior mammogram.
For example, if a 2D mammogram shows an area of concern, radiologists may want to further investigate with a diagnostic mammogram, ultrasound or biopsy. Looking at the same breast tissue in 3D, the radiologist may now see that the tissue is in fact normal breast tissue that was simply overlapping in the 2D mammogram, creating the illusion of an abnormal area. In this scenario, the patient would likely have avoided a callback for an additional mammogram by utilizing tomosynthesis in the first place.
The radiation dose is approximately the same for tomosynthesis as it is for 2D mammography. So the radiation is roughly doubled when doing a 2D mammogram along with tomosynthesis. Even this combined dose is still below the FDA-regulated limit for 2D mammography and has been found by the FDA to be safe and effective for patient use.
3D mammography can help radiologists rule out abnormalities that may have looked suspicious in a 2D mammogram, so the likelihood you'll be called back may be less. However, there is still a chance that some patients will require additional mammographic views and/or ultrasound.
Because this technology is so new, insurance does not cover the 3D portion of the mammogram. However, the 2D portion of the exam will be billed to insurance, which is usually covered at 100% by most plans.
A small flat fee will be due at the time of service. This fee helps offset the cost of this very new technology and includes the radiologist's interpretation of the additional 3D imaging.
No. The 3D images must be acquired at the same time as the 2D images.