Tomosynthesis vs. Mammography: How Do They Differ?

In In The News by Barbara Jacoby



Tomosynthesis is an imaging or X-ray technique that can be used to screen for early signs of breast cancer in women with no symptoms. This type of imaging can also be used as a diagnostic tool for women that are having breast cancer symptoms. Tomosynthesis is an advanced type of mammography. A tomosynthesis takes multiple images of the breast. These images are sent to a computer that uses an algorithm to combine them into a 3-D image of the entire breast.

Tomosynthesis vs. mammography


Tomosynthesis and mammography are similar in that they’re both breast imaging techniques that are used to detect signs of breast cancer. They can both be used for annual exams and to check the progression of breast cancer.


Tomosynthesis is considered a more advanced and detailed imaging technique than a mammogram in the following ways:

  • Tomosynthesis can look at multiple layers of the breast in a 3-dimensional (3-D) image. This allows this method to fill in the gaps or limitations that traditional mammograms have, since a mammogram only captures a 2-dimensional (2-D) image.
  • The 3-D imaging of a tomosynthesis allows your doctor to see small lesions and other signs of breast cancer earlier than a traditional mammogram.
  • It can detect breast cancer before many women ever start to have any symptoms. Tomosynthesis can often discover breast cancer years before you or your doctor could feel it or see any symptoms.
  • Tomosynthesis helps to reduce false positives that mammograms can give and is more accurate than a regular mammogram.
  • It can also be much more accurate than mammography in screening for breast cancer in women who have dense breasts.
  • In terms of comfort, tomosynthesis doesn’t require your breast to be compressed like they would be during traditional mammography.

Cost of tomosynthesis

Many insurance companies are now covering tomosynthesis as part of breast cancer screening. However, if yours does not, the average out of pocket cost ranges from $130 to $300.

Tomosynthesis procedure

The procedure for a tomosynthesis is very similar to that of a mammogram. A tomosynthesis uses the same imaging machine as a mammogram. However, the type of images it takes is different. Not all mammogram machines are able to take tomosynthesis images. Overall, the tomosynthesis procedure takes around 15 minutes. The following is what you should expect from this procedure.

  1. When you arrive for your tomosynthesis, you will be taken to a changing room to remove your clothes from the waist up and provided with a gown or cape.
  2. You will then be taken to the same machine or type of machine that performs a traditional mammogram. The technician will position one breast at a time in the X-ray area.
  3. Your breast will not be tightly compressed like during a mammogram. However, the plates will still be lowered to just hold your breast still during the imaging process.
  4. The X-ray tube will be positioned over your breast.
  5. During the procedure, the X-ray tube will move by making an arch over your breast.
  6. During the procedure, 11 images will be taken of your breast in 7 seconds.
  7. You will then change positions so that images can be taken of your other breast.
  8. After this procedure is complete, your images will be sent to a computer that will make a 3-D image of both breasts.
  9. The final image will be sent to a radiologist and then your doctor to be examined.

Preparing for the procedure

Preparing for a tomosynthesis is similar to preparing for a traditional mammogram. Some preparation tips include the following:

  • Wear two-piece clothing. This makes undressing for the procedure easier and allows you to remain dressed from the waist down.
  • Request your prior mammograms. This allows your doctor to compare both images to better see any changes that may occur in your breasts.
  • Let your doctor and imaging technician know if you think you may be pregnant or if you are nursing. Your doctor may want to use a different procedure or take additional precautions to protect your baby.
  • Schedule the procedure a week or two after your menstrual cycle to reduce breast tenderness.
  • Avoid or reduce the amount of caffeine you eat or drink for two weeks prior to your procedure to reduce possible breast tenderness.
  • Do not use deodorant, powder, lotion, oil, or cream from the waist up on the day of the procedure.
  • Let your doctor and imaging technician know about any symptoms you may be having, surgeries to or near your breasts, family history of breast cancer, or any hormone use prior to the procedure.
  • Let the imaging technician know if you have breast implants prior to the procedure.
  • Ask when you should expect the results.

Pros and cons


Some benefits of using tomosynthesis in addition to or instead of a traditional mammogram include the following:

  • better results and screening for dense breasts
  • less discomfort since there is no breast compression
  • earlier detection of breast cancer with symptoms
  • detection of breast cancer in women with no symptoms


Some risks of using tomosynthesis instead of a traditional mammogram may include the following:

  • There’s more exposure to radiation due to more images being taken of each breast. However, the radiation is still minimal and considered safe. The radiation leaves your body shortly after the procedure.
  • Specific algorithms for 3-D imaging construction may vary, which may affect the results.
  • The arc of the movement of the X-ray tube may vary, which may cause variation in the images.
  • Tomosynthesis is still a relatively new procedure and not all mammography locations or doctors will be familiar with it.

Tomosynthesis is most helpful in screening for breast cancer in women with dense breasts. Tomosynthesis is still a relatively new procedure, so it’s not available at all locations that use mammography. Be sure to ask your doctor or mammography clinic if this imaging option is available for you.

If you know you have dense breasts, or have possible symptoms of breast cancer, you can discuss the option of having tomosynthesis imaging done in addition to or instead of a traditional mammogram.