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You closely examine your breasts and notice a lump, redness or nipple ulceration. You consult your doctor, and you know that you may be asked to have a mammogram. Maybe you also received your letter from the Québec Breast Cancer Screening Program.  

This is when the anxiety starts to mount. You imagine your breasts being crushed like a sheet of paper by a huge metal machine!

But don’t panic! Mammography isn’t that scary and it’s actually very useful.

Why have a mammogram?

There are two types of mammograms: screening mammograms and diagnostic mammograms.

A screening mammogram is an exam that the Québec Breast Cancer Screening Program invites you to undergo every two years from age 50 to 74.

Why this specific age group? Simply because women in this age range have the highest rate of breast cancer. By offering a screening mammogram every two years, the disease can be detected before the first symptoms appear, allowing for early management and avoiding the need for more aggressive treatment. Studies have shown that this program really does save lives by detecting breast cancer before the first signs appear.

It’s also possible to have a screening mammogram before the age of 50 or after 74. Even though it’s a screening, women need a medical prescription justifying the reason for performing the test early or late. A family history of breast and/or ovarian cancer will almost always be the reason for the request.

A diagnostic mammogram, on the other hand, is performed at the request of your family doctor on the basis of breast symptoms. You can’t decide to have a mammogram of your own accord; it must absolutely be prescribed by your doctor. After a clinical breast exam, you’ll be asked a few questions about your risk factors to determine if mammography is right for you.

What is the difference between a screening mammogram and a diagnostic mammogram?

Don’t be confused by these two terms. They refer to exactly the same test; the same room, same equipment, same technique, same number of images, same positions and the same diligence. The same! The radiologists who make the diagnoses will also be just as thorough in their analysis. In both cases, the success of the exam depends on the quality of the positioning and proper collaboration between the technologist and the person undergoing the mammogram.


What is a mammogram?

First of all, it’s important to know that only a medical imaging technologist certified by the Ordre des technologues en imagerie médicale, en radio-oncologie et en électrophysiologie médicale du Québec (OTIMROEPMQ) can perform this test. Note that no man currently performs mammography in Quebec, which is why you’ll always be greeted by a female technologist!

Mammography is a medical imaging method that takes images of the inside of the breasts from different angles using low-dose X-rays. It’s the most effective test to quickly detect possible breast cancer, even at a very early stage and without any symptoms.

Did you know that a man can have a mammogram? Remember that men account for 1% of breast cancer cases. Men who notice changes in their chest may also have a mammogram and may undergo a screening if they have risk factors. Here again, the test can only be done with a valid medical prescription.

At what age should I start having mammograms if I’m at risk?

Unfortunately, there’s no clear-cut answer to this question. Each woman is unique and has her own personal set of risk factors.

Mammography isn’t advisable in young women because of breast composition. Breasts are generally denser in women under 35, which could make it more difficult to analyze the mammogram. In this case, the doctor may recommend another imaging technique, such as breast ultrasound or magnetic resonance imaging.


How do I prepare for a mammogram?

There’s no special preparation, but there are some tips to make everything go as smoothly as possible:

  • Avoid dresses and opt for clothing that can only be removed from the top.
  • Before the test, it’s very important not to apply deodorant, antiperspirant, cream, powder or perfume to the breasts and armpits.
  • Avoid wearing necklaces, dangling earrings or any other bulky jewelry.
  • A few days before, avoid caffeine-based foods, such as chocolate. If you tend to have sensitive breasts, you can ask to have the test done seven to 10 days after your period.

What happens during a mammogram?

A mammogram isn’t as terrible as you might think. It’s actually a very simple test that takes about 15 to 20 minutes.

First, a technologist will greet you and review the questionnaire you were given when you arrived. Then, she will ask you to remove your top so that your chest is exposed. She will position you on the device and you will remain in a standing position throughout the test.

The breasts will then be compressed one by one between two compression trays. A minimum of two images will be taken from two different angles, horizontal and oblique (from the side), to properly locate and situate any possible abnormalities in the breasts.

The basic exam involves two images per breast. It’s always important to take two orthogonal views to properly locate and situate any possible abnormalities in the breasts. That’s it!

There’s no risk of injury or damage associated with this exam, other than mild discomfort during compression. Don’t forget that these 20 minutes can save your life.


What if I have breast implants?

You’ll still be able to undergo the exam, since having breast implants isn’t a contraindication to mammography. The equipment used is the same, but the procedure is different. The method used is designed to avoid significant compression of the implant to eliminate the risk of rupture during the exam. This method allows for a complete analysis of the gland, without being hindered by the implants.

The only real contraindication to a mammogram is recent surgery involving the breasts (reconstruction, reduction, augmentation, and so on) or the sternum (heart surgery).


How are the results explained?

Radiologists refer to the BI-RADS (Breast Imaging-Reporting and Data System) classification system to describe mammogram results and suggested next steps.

The classification is as follows:

    • BI-RADS 0: Incomplete assessment, further imaging is needed
    • BI-RADS 1: Normal mammogram
    • BI-RADS 2: There are benign (i.e., not serious) abnormalities that do not require monitoring or further examination
    • BI-RADS 3: There is an abnormality that is probably benign for which short-term monitoring (three or six months) is recommended
    • BI-RADS 4: There is an undetermined or suspicious abnormality
    • BI-RADS 5: There is an abnormality suggestive of cancer

Depending on the results of the images, the doctor will recommend either doing nothing, closely monitoring, or undergoing more in-depth tests, such as a breast ultrasound. When the imaging is classified as BI-RADS 4 or 5, the doctor will definitely request a biopsy. A biopsy is the only test that can confirm the definitive diagnosis of breast cancer.

The mammogram results also include a classification of breast density. It’s broken down into four categories, A to D:

    • A: Breasts almost entirely made up of fatty tissue
    • B: Breasts made up of scattered areas of fibroglandular density
    • C: Breasts that are heterogeneously dense, which can mask small masses.
    • D: Breasts that are extremely dense, decreasing the sensitivity of mammography.

The fattier the tissue is, the more the image quality will be able to show if there’s a mass or lesions. Conversely, tissue that is glandular (which secretes breast milk) or fibrous could compromise the image quality. When the tissue is more fibrous than fatty, it will be denser according to the proportion of tissues.

Note that the term “fatty breasts” has nothing to do with the size of your breasts. A large breast could be categorized as D (extremely dense breast) and a smaller breast could be categorized as A (almost entirely fatty breasts). You cannot reliably determine the exact composition of your breast tissue on your own; only medical imaging can do this.

If breasts are too dense, it can reduce the quality of the image and prevent a mass from being seen. In this case, the doctor may recommend additional tests, such as breast ultrasound.

Here are examples of breasts that are not very dense and breasts that are. (Photo credit: OTIMROEPMQ)



In recent years, tomosynthesis (often called “3D mammography”) has made an appearance in Quebec. This breast exploration technology makes it possible to view the mammary gland in “slices” that are just a few millimetres thick and generate a three-dimensional computer reconstruction of the breast. You may have already had a tomosynthesis during a mammogram without even realizing it. How is this possible?

To perform this exam, the same equipment is used as for a standard mammogram. The positioning is the same, the compression is the same and two images are taken of each breast in two different positions. However, during exposure to the X-rays, the device moves in an arch, producing images by excessive angulation. Even though the top of the device moves during imaging, your breast remains stationary and there is no risk of injury to you. This approach is highly recommended for young women and in people with high breast density.

Lastly, the benefits of mammography outweigh the discomfort it can cause. If you have symptoms that you’re concerned about, speak to your doctor as soon as possible and investigate, even if the exam and results scare you. Most of the abnormalities detected turn out to be benign, but if they’re malignant (cancerous), it’s better to find out sooner rather than later.

If you have any questions or concerns about breast cancer, we’re here for you before, during and after diagnosis and treatment. Don’t hesitate to contact us. A professional will speak to you confidentially: 1 855 561-ROSE

We would like to thank the OTIMROEPMQ and Audrey Bouvier, t.i.m., for her contribution to this article.


Fondation cancer du sein du Québec. « Dépistage et facteurs de risque ». Ruban rose, 2021. https://rubanrose.org/minformer/a-propos-du-cancer-du-sein/depistage-et-facteurs-de-risques/. Ruban rose. « Mammographie ». Consulté le 23 septembre 2021. https://rubanrose.org/minformer/depistage-et-diagnostic/mammographie/. Ruban rose. « Statistiques sur le cancer du sein | M’informer ». Consulté le 27 septembre 2021. https://rubanrose.org/minformer/a-propos-du-cancer-du-sein/statistiques-sur-le-cancer-du-sein/. Sickles, EA, D’Orsi CJ, Bassett LW, et al. ACR BI-RADS® Mammography. In: ACR BI-RADS® Atlas, Breast Imaging Reporting and Data System. Reston, VA, American College of Radiology; 2013.


Image tomosynthèse

Programme Québécois de dépistage du cancer du sein (consulté en mai 2023) http://www.depistagesein.ca/wp-content/uploads/2020/10/Tomosynthese.jpg