Mammography: How It’s Done and What It Detects

What Is Mammography?

Mammography is a specialized X-ray technique used to examine breast tissue for signs of cancer or other abnormalities. It works by using low-dose radiation to create images of the inside of the breasts, allowing doctors to detect changes that may not be felt during a physical exam.

This test is most commonly used to screen for breast cancer in its early stages, when it's easier to treat. It can also help investigate symptoms like lumps, pain, or nipple discharge.

Types of Mammography

There are two main types of mammography, depending on the situation:

1. Screening Mammography - Used as a routine test for people without any symptoms. It aims to find early signs of breast cancer, often before it causes noticeable changes.
2. Diagnostic Mammography - Done when there are symptoms such as a lump or pain, or when a screening mammogram shows something unusual. It provides more detailed images for a clearer understanding of what’s happening.

What About 3D Mammography?

Many centers now use digital breast tomosynthesis (DBT), also called 3D mammography. It captures multiple images from different angles, producing a layered, more detailed view. This method is especially helpful for people with dense breast tissue, where traditional 2D images might miss small abnormalities.

Why Is Mammography Done?

Mammography is one of the best tools for finding breast cancer early, often before symptoms appear. Early detection greatly increases the chances of successful treatment.

You may need a mammography exam if:

• You are age 40 or older and due for routine breast cancer screening.
• You feel a lump or thickening in your breast.
• You have nipple discharge, pain, or a change in breast shape.
• A previous mammogram showed an abnormal result
• You have a family history of breast cancer

Mammography Guidelines

According to the American Cancer Society, here’s when routine mammography is recommended:

How to Prepare for a Mammography Appointment

Getting ready for your mammography exam properly can make the experience easier and more accurate.

Before the test:

• Avoid using deodorants, powders, or lotions under your arms or on your breasts. These can interfere with the X-ray image.
• Try to schedule it a week after your period if your breasts are tender before menstruation.
• Wear a two-piece outfit so you only have to remove your top.
• Let the technician know if you have breast implants or if there’s a chance you might be pregnant.
• If you’ve had previous mammograms, bring your old results for comparison.

How Mammography Is Performed

A mammography exam usually takes about 15 to 30 minutes and is done by a trained technician.

Here’s what to expect:

1. Positioning - You’ll stand in front of the mammography machine, and your breast will be placed on a flat plate.
2. Compression - Another plate presses down gently to spread the tissue evenly. This improves image quality.
3. Imaging - X-ray images are taken, usually from top and side views.
4. Repeat for both breasts - The same steps are done on the other side.

Is It Painful?

Some people feel mild discomfort or pressure, especially during compression. It lasts only a few seconds. If you're in pain, tell the technician; they may be able to make adjustments.

What Can Mammography Detect?

Mammography can reveal various changes in the breast tissue. The resulting mammograms are black-and-white images that show different shades based on tissue density.

Common findings include:

• Normal results - No signs of cancer or abnormal changes.
• Benign conditions - Non-cancerous findings like cysts or calcium deposits.
• Suspicious areas - Lumps or shadows that may need more tests, like a breast ultrasound or biopsy.

Risks and Limitations of Mammography

While mammography is a very effective tool, it does come with a few limitations:

• Radiation exposure - The dose is very low, and the benefits far outweigh the risks.
• False positives - Some results look abnormal but turn out to be harmless.
• False negatives - Rarely, a cancer might be missed, especially in people with dense breasts.
• Discomfort - The compression may feel uncomfortable, but only for a few moments.
• Pregnancy and breastfeeding - Hormonal changes affect breast density, making mammograms harder to interpret. Ultrasound is often preferred during pregnancy unless absolutely necessary.
• Young women under 30 - Mammography is generally avoided unless strongly indicated, as their breast tissue is more sensitive to radiation and often too dense for accurate imaging.
• Previous breast surgery - Scar tissue or implants can make the test harder to interpret. Special imaging techniques may be needed.

Despite these limitations, mammography remains the most reliable screening tool for early breast cancer detection.

What the Mammography Results Mean

After your exam, a radiologist reviews the mammogram and sends a report to your doctor. The results usually fall into one of these categories:

1. Negative (No signs of cancer)

Everything looks normal. You’ll continue regular screenings based on your age and risk.

2. Inconclusive (Need more tests)

The image wasn’t clear, or something unusual was seen. Your doctor might recommend:

• A repeat mammography
• A breast ultrasound
• A biopsy if something needs closer examination

3. Positive (Abnormal finding)

This doesn’t mean you have cancer, but further tests are needed to find out more. Your doctor will guide you through the next steps.

Alternatives to Mammography

In some cases, other tests may be more appropriate depending on your age, risk, or breast density:

• Breast Ultrasound - Uses sound waves to look at lumps or dense tissue. Often used as a follow-up.
• Breast MRI - Gives a very detailed view, especially useful for people at high risk.
• Clinical Breast Exam - A physical exam by your doctor to feel for any unusual lumps or changes.

If mammography isn't right for you, your doctor will help choose the best method based on your situation.