Mammography

Mammography is a low-dose X-ray examination of the breast and is the most widely used tool for detecting breast cancer, often before a lump can be felt. It serves two main purposes.

Screening mammography is performed at regular intervals in women who have no symptoms, with the goal of finding cancer at an early, more treatable stage.

Diagnostic mammography is used to investigate a specific concern, such as a lump, pain, or nipple discharge, or to take a closer look at an area flagged on a screening study.

Mammography is particularly good at detecting tiny calcium deposits called microcalcifications, which can be one of the earliest signs of cancer. Many centers now use a technique called tomosynthesis, sometimes described as three-dimensional mammography, which takes images in thin slices and can improve detection, especially in denser breasts.

Little preparation is required, but a few simple steps make the examination easier and more accurate. It is helpful to schedule the test for a time when the breasts are least likely to be tender, which for many women is the week after their menstrual period. On the day of the examination, deodorant, powder, lotion, or perfume should not be applied to the breasts or underarms, because some of these products can leave specks on the image that resemble calcifications. Wearing a two-piece outfit allows the upper clothing to be removed easily, and bringing any previous mammogram images allows the radiologist to compare them with the new study.

During the examination, each breast is placed on a flat surface and gently but firmly compressed between two plates for a few seconds while the image is taken. This compression spreads the breast tissue so that it can be seen clearly and keeps it still, which improves image quality and keeps the radiation dose low. At least two views are usually taken of each breast. The pressure can feel uncomfortable, but it lasts only a short time, and the entire appointment is typically completed within about twenty minutes.

Mammography is very safe, and the amount of radiation involved is small. The main limitations are not physical risks but the possibility of an uncertain result. Occasionally a normal area can look suspicious and lead to additional tests, and in some cases — particularly in dense breasts — a cancer may not be visible. For most people, the benefit of early detection clearly outweighs these limitations.

The radiologist categorizes the findings using a standardized system known as BI-RADS, which indicates how likely a finding is to be benign or to require further evaluation. A normal result usually means returning for routine screening at the recommended interval. If something needs a closer look, additional mammographic views, an ultrasound, or an MRI may be arranged, and a biopsy is recommended when a finding appears suspicious.

FREQUENTLY ASKED QUESTIONS

Does the radiation from a mammogram cause cancer?

• The amount of radiation used in a mammogram is very small, and the benefit of detecting breast cancer early is widely considered to far outweigh this minimal risk.

Does a mammogram hurt?

• The breast is compressed for a few seconds, which can feel uncomfortable, but the pressure is brief. Scheduling the test for when your breasts are least tender can make it more comfortable.

How often should I have a mammogram?

• Screening recommendations vary depending on your age, personal risk, and local guidelines, so it is best to discuss the right schedule for you with your healthcare provider.