How Does A Mammogram Work Procedure Types Results?

A mammogram is an X-ray picture of the breast. It can find breast cancer early, sometimes years before a lump can be felt. The test takes about 20 minutes. A technologist positions each breast between two plastic plates, the plates press down for a few seconds, and a low-dose X-ray image is captured. A radiologist then reads the images and sends a report to your doctor.

How Does A Mammogram Work?

A mammogram uses X-rays, a form of radiation, to create images of the inside of the breast. Breast tissue is made of fat, glands, and connective tissue. These parts absorb X-rays differently, so they show up in different shades of gray and white on the image.

Fat appears dark. Dense glandular tissue and any calcifications appear white. A radiologist looks for patterns that stand out from normal tissue.

Two main types of X-ray systems are used today:

• Film-screen mammography uses photographic film to capture the image.
• Digital mammography captures the image electronically and stores it on a computer.

Digital images can be viewed and enlarged on a screen. Some research suggests digital imaging may detect cancer slightly better in women under 50 and in women with dense breasts, though the difference in overall outcomes is small. Both methods are considered effective screening tools.

What Happens During The Procedure?

The procedure is straightforward. You undress from the waist up and stand in front of the machine. A technologist places one breast at a time on a flat plate.

A second plate comes down from above and compresses the breast. The pressure lasts only a few seconds. It can feel uncomfortable, but it should not be painful. Compression matters because it spreads the tissue out, which lowers the radiation dose and produces a clearer image.

For a standard screening, two views are taken of each breast. One view is from top to bottom. The other is from side to side. The whole visit usually takes about 20 minutes, with only a few minutes of actual compression.

You may be asked to hold your breath for a moment during each image. Some women find the test mildly uncomfortable. Others feel little. Discomfort tends to be less if you avoid scheduling the test during the week before your period, when breasts are often more tender.

You get the results later, not during the visit. The images must be reviewed by a radiologist.

What Are The Different Types Of Mammograms?

Mammograms fall into two broad groups: screening and diagnostic. Within those, there are several technologies.

A screening mammogram is done when you have no symptoms. Its goal is to find cancer early in women who feel fine. A diagnostic mammogram is done when there is a symptom, such as a lump, nipple discharge, or breast pain, or when a previous mammogram showed something that needs a closer look. A diagnostic mammogram takes more images and often includes extra views.

Beyond that, the technology used can vary:

• Digital mammography is the most common type in the United States today.
• 3D mammography, also called digital breast tomosynthesis, takes multiple images from different angles and builds a three-dimensional picture of the breast.
• Digital breast tomosynthesis is often combined with a standard 2D image or used to create a synthetic 2D view.

3D mammography can improve cancer detection and reduce the number of women called back for extra testing. Studies have found this fairly consistently. Whether it lowers the death rate from breast cancer more than standard digital mammography is still being studied.

There is also contrast-enhanced mammography, which uses an injected dye. This is used in some specialized settings, not as routine screening. Magnetic resonance imaging (MRI) is not a mammogram, but it is sometimes used along with mammography for women at high risk.

How Accurate Is A Mammogram?

No test is perfect. Mammography finds many cancers, but it also misses some. A missed cancer is called a false negative. A result that looks suspicious but turns out not to be cancer is called a false positive.

Accuracy depends on several things, including breast density, age, and the skill of the radiologist. Breast density matters a lot. On a mammogram, dense tissue looks white, and so do many cancers. That makes cancer harder to spot in dense breasts. About half of women over 40 have dense breasts.

False positives are common. Many women get called back for extra images at some point. Most of the time, the follow-up shows nothing is wrong. Still, the waiting period is stressful, and extra testing can lead to a biopsy that turns out to be benign.

Mammography also finds some cancers that would never have caused harm in a woman’s lifetime. This is called overdiagnosis. It is real, and its exact size is debated among researchers. It means some women are treated for a cancer that would not have threatened their health.

The balance of evidence shows that regular mammography reduces deaths from breast cancer in women in the recommended age groups. That benefit is well established. The size of the benefit, and the ideal age to start and stop, are still discussed among medical organizations.

What Do The Results Mean?

After a mammogram, a radiologist assigns a score using a standard system called BI-RADS. This stands for Breast Imaging Reporting and Data System. The score runs from 0 to 6 and tells your doctor how to act.

The categories work roughly like this:

• 0 means the images were not clear enough to read. You need more imaging.
• 1 means negative. Nothing unusual was seen.
• 2 means benign. Something was seen, but it is not cancer.
• 3 means probably benign. Short-term follow-up is suggested.
• 4 means suspicious. A biopsy is usually recommended.
• 5 means highly suspicious. Biopsy is strongly recommended.
• 6 means a known cancer is present, usually after a prior diagnosis.

Most results come back as 1 or 2. If your report says 0, that does not mean you have cancer. It means the radiologist needs more pictures. A 3 usually means a repeat mammogram in a few months, not a biopsy right away.

Only a biopsy can confirm whether something is cancer. Imaging can suggest it, but it cannot prove it.

When Should You Get One?

Guidelines differ, and that can be confusing. Different medical groups recommend different starting ages and intervals.

Some organizations suggest starting screening at age 40 and having one every year or two. Others suggest starting at 50 and screening every two years. The differences come down to how each group weighs benefits against harms like false positives and overdiagnosis.

What most groups agree on: women at average risk should talk with their doctor about when to start and how often to screen. Women at higher risk, due to family history, certain genetic mutations, or prior chest radiation, often start earlier and may need MRI in addition to mammography.

No single schedule fits everyone. Your personal risk, your breast density, and your preferences all matter. The decision is best made with your doctor, not from a general rule alone.

Does It Hurt, And Is It Safe?

Most women describe the pressure as uncomfortable rather than painful. It lasts only seconds per image. If you have tenderness, scheduling away from the week before your period can help.

Mammography uses a low dose of radiation. The dose is small and considered safe for screening. The benefit of finding cancer early is generally judged to outweigh the small radiation risk for women in the recommended age groups.

You cannot have a mammogram if you are pregnant, because of the radiation. If you might be pregnant, tell the technologist before the test. Breastfeeding women can usually have mammograms, but they should let the staff know, since milk can affect the images.

Mammograms do not prevent cancer. They find it earlier, when treatment is often more effective. That distinction matters when thinking about what the test can and cannot do.