Tomosynthesis

Tomosynthesis, also known as 3D mammography, is an advanced X-ray imaging test that creates a detailed three-dimensional view of the breast. It takes multiple images from different angles, which a computer then combines into thin "slices." This technology helps doctors see through breast tissue more clearly, especially in dense breasts, aiding in breast cancer screening and diagnosis and potentially reducing the need for follow-up tests.

What is Tomosynthesis?

Tomosynthesis, also known as 3D mammography, is an advanced X-ray imaging test that creates a three-dimensional picture of the breast. Unlike traditional 2D mammography, it takes multiple images from different angles. A computer then combines these images into thin "slices," allowing doctors to see through breast tissue more clearly, which can help detect breast cancer.

This advanced imaging technique works by having an X-ray machine move in an arc over the breast, taking a series of low-dose images from various angles. These individual images are then sent to a computer. The computer uses sophisticated software to reconstruct them into a detailed, layered 3D image of the breast tissue. Traditional 2D mammography produces a single, flat image of the breast. This can sometimes lead to overlapping tissue appearing as an abnormality, or it can hide a true abnormality. Tomosynthesis helps overcome this challenge by providing a clearer view, much like flipping through pages of a book to see each layer of tissue separately. Tomosynthesis can be performed as a standalone test or in combination with a traditional 2D mammogram. In some cases, a 2D image can even be "synthesized" or created from the 3D images, meaning a separate 2D exposure is not always needed.

Why it's ordered

Tomosynthesis is ordered primarily for breast cancer screening and diagnosis. It is especially beneficial for people with dense breast tissue, where traditional 2D mammograms can be harder to interpret. This test can help doctors find more cancers and reduce the number of times people are called back for additional imaging due to unclear results.

Doctors order tomosynthesis for two main reasons: as a regular screening tool to check for breast cancer in people without symptoms, and as a diagnostic tool to investigate a lump, pain, or other breast changes. Its ability to provide a more detailed view makes it valuable in both situations. One of the key advantages of tomosynthesis is its improved ability to detect breast cancer, particularly in people who have dense breast tissue. Dense breasts contain more fibrous and glandular tissue than fatty tissue, which can make it difficult to see cancers on a standard 2D mammogram because both dense tissue and tumors appear white. Another important benefit is that tomosynthesis can reduce the number of false positive results. A false positive occurs when a mammogram suggests a possible problem that turns out not to be cancer. By providing clearer images, tomosynthesis can help avoid unnecessary follow-up tests and reduce anxiety for patients. While it improves detection and reduces callbacks, current evidence does not clearly show that tomosynthesis reduces breast cancer deaths (mortality).

How to prepare

Preparing for tomosynthesis is similar to preparing for a traditional mammogram. You should inform your doctor or the technologist if you are pregnant or think you might be. On the day of the test, avoid using deodorant, antiperspirant, lotion, or powder on your breasts or underarms, and remove any jewelry.

Before your tomosynthesis appointment, it is crucial to tell your doctor or the X-ray technologist if there is any chance you could be pregnant. X-rays involve radiation, and while the dose is low, precautions are taken during pregnancy to protect the developing baby. On the day of your exam, do not apply deodorant, antiperspirant, lotion, or powder to your underarms or breasts. These products can contain metallic particles that may show up on the X-ray images, making them look like calcifications or other abnormalities. This can lead to unclear results or the need for repeat imaging. It is also recommended to remove all jewelry, especially necklaces, before the test. You will be asked to remove your clothing from the waist up, so wearing a two-piece outfit can make the process more convenient. Be sure to inform the technologist about any breast implants or previous breast surgeries you may have had.

What to expect during

During tomosynthesis, you will stand in front of an X-ray machine, and a technologist will position one of your breasts at a time on a special platform. Your breast will be compressed firmly between two plates, similar to a traditional mammogram. The X-ray tube will then move in an arc over your breast, taking several images.

The procedure for tomosynthesis is very similar to a standard 2D mammogram. A trained X-ray technologist will guide you through the process. You will stand in front of the mammography machine, and the technologist will carefully position one of your breasts on a flat plate. Your breast will then be compressed firmly by another plate. This compression is necessary to spread out the breast tissue, which helps to obtain clear images and reduces the amount of radiation needed. While the compression can cause discomfort or even pain for a brief period, it is temporary and lasts only a few seconds for each view. Once your breast is compressed, the X-ray tube will move in a gentle arc above your breast, taking multiple low-dose images from different angles. You will need to remain very still during this part of the process. The entire procedure, including positioning and imaging, typically takes slightly longer than a 2D mammogram, often around 10 to 15 minutes.

Understanding your results

After your tomosynthesis, a radiologist (a doctor specializing in medical imaging) will carefully review the images and prepare a report. This report will then be sent to your primary doctor or the doctor who ordered the test. Your doctor will discuss the findings with you, explain what they mean, and determine if any further steps are needed based on your personal health history.

A radiologist, who is a medical doctor with specialized training in interpreting medical images, will meticulously examine the detailed 3D images from your tomosynthesis. They will look for any subtle changes or abnormalities in your breast tissue, such as masses, distortions, or tiny calcium deposits (calcifications) that could indicate breast cancer. Once the radiologist has completed their analysis, they will generate a comprehensive report. This report is then sent to your referring doctor, who will be responsible for discussing the results with you. Your doctor will explain the findings in a way that is easy to understand and will put them into context with your overall health, medical history, and any symptoms you may have. It is important to remember that this information describes general results. Your doctor is the only one who can interpret your specific tomosynthesis results and advise you on the appropriate next steps. Depending on the findings, your doctor might recommend routine follow-up, additional imaging tests, or a biopsy if a suspicious area is identified.

Risks

The main risk associated with tomosynthesis is exposure to a small amount of radiation, similar to other X-ray procedures. While the radiation dose is slightly higher than a traditional 2D mammogram, it remains within safe limits. Other potential risks include false positive results, which can lead to anxiety and additional tests, and false negative results, where a cancer might be missed.

Like all X-ray imaging tests, tomosynthesis involves exposure to a small amount of radiation. The radiation dose from tomosynthesis is slightly higher than that of a standard 2D mammogram. However, this dose is still considered low and falls within established safety guidelines, meaning the potential benefits of early cancer detection typically outweigh this small risk. One potential risk is a false positive result. This happens when the tomosynthesis images show an area that looks suspicious for cancer, but after further investigation, it turns out to be benign (not cancer). False positives can cause significant anxiety and may lead to additional tests, such as more imaging or even a breast biopsy, which can be stressful and involve extra costs. Conversely, there is also a small risk of a false negative result. This occurs when a breast cancer is present but is not detected by the tomosynthesis. No screening test is 100% accurate. If you notice any new lumps, changes in breast size or shape, nipple discharge, or other unusual symptoms, it is crucial to discuss them with your doctor immediately, even if your recent mammogram results were normal.

Frequently asked questions

Is tomosynthesis covered by insurance?

Insurance coverage for tomosynthesis (3D mammography) can vary depending on your specific insurance plan and where you live. Many insurance providers now cover 3D mammography, especially for screening purposes, recognizing its benefits. It is always best to contact your insurance company directly before your appointment to understand your benefits and any potential out-of-pocket costs.

How long does a tomosynthesis take?

A tomosynthesis procedure typically takes slightly longer than a traditional 2D mammogram. While the breast compression time for each image is still only a few seconds, the entire process, including positioning and taking multiple images from different angles, might take about 10 to 15 minutes in total. This is still a relatively quick outpatient procedure.

Is tomosynthesis more painful than a regular mammogram?

The experience of breast compression during tomosynthesis is very similar to that of a traditional 2D mammogram. You may feel pressure or discomfort, and some people experience pain, but this sensation is temporary. The compression is necessary to get clear images and usually lasts only a few seconds for each view, similar to a 2D mammogram.

Can men get tomosynthesis?

Yes, men can get tomosynthesis if their doctor recommends it. While breast cancer is much less common in men, it can occur. If a man has symptoms like a lump, nipple discharge, or other breast changes, a doctor might order tomosynthesis as part of the diagnostic process to get a clearer view of the breast tissue.

What is the difference between 3D mammography and tomosynthesis?

There is no difference between 3D mammography and tomosynthesis; they are two different names for the same advanced imaging technique. Both terms refer to the process where an X-ray machine moves in an arc to capture multiple images of the breast, which a computer then reconstructs into a detailed three-dimensional view.

Do I still need a regular mammogram if I get tomosynthesis?

Tomosynthesis can be performed either alone or in combination with a traditional 2D mammogram. In some cases, a 2D image is "synthesized" from the 3D images, meaning a separate 2D exposure isn't needed. Your doctor will determine the most appropriate type of mammogram for your individual screening or diagnostic needs based on your breast density and medical history.

Sources

• MedlinePlus — Tomosynthesis
• Mayo Clinic — Tomosynthesis
• Cochrane Library — Tomosynthesis