What is a 3D mammogram?
A 3D mammogram, also known as digital breast tomosynthesis (DBT), uses a series of two-dimensional images to build a three-dimensional image of the breast.
It can be used:
- As a screening tool to detect breast cancer
- As a diagnostic tool to further evaluate abnormalities detected in conventional 2D mammograms
The mammogram machine takes multiple low-dose X-ray images of each breast from different angles. The computer software will process these thin slice images to reconstruct into detailed 3D images of the breast.
While mammograms are the best screening tool for breast cancer available today, mammograms do not detect all breast cancers.
3D mammogram (DBT) vs conventional mammography
During a DBT exam, the breast is positioned and compressed the same way as it is for a conventional 2D mammogram.
However, during the DBT exam, the X-ray tube moves in an arc over the breast, taking multiple images of the breast as it moves.
Many studies have shown DBT's superiority over 2D mammography since it was approved by FDA in 2011, particularly in terms of the cancer detection rate and the recall rate, or the rate at which patients are called back for additional imaging.
Why do you need a 3D mammogram?
A 3D mammogram is often used for breast cancer screening. Even if you have no noticeable symptoms of breast cancer, you should still get screened regularly so that any potential problems can be detected and treated early.
According to the Health Promotion Board in Singapore, women between 40 – 49 years of age should go for regular mammogram screenings once a year. If you are 50 years old or above, you should go for mammogram screenings once every 2 years.
A 3D mammogram can also be used to diagnose certain breast abnormalities, such as a suspicious lump or thickening of the skin. The procedure is especially useful for women with overlapping or dense breast tissue, which can be hard to examine using standard mammography.
Compared to a traditional mammogram, a 3D mammogram offers benefits such as:
- Better detection of small masses hidden in dense breast tissue
- Higher accuracy of breast cancer detection
- Lower rate of false-positive cases
- Reduces the need for follow-up imaging
What are the risks of a 3D mammogram?
Sometimes a mammogram may identify an abnormality which appears like cancer, but turns out to be normal. This is called a false positive. Likewise, there is also a small probability that mammograms may not detect cancer hidden by normal breast tissues. This is called a false negative.