A mammogram is an x-ray picture of the breast. It can be used to check for breast cancer in women who have no signs or symptoms of the disease. It can also be used if you have a lump or other sign of breast cancer.

Screening mammography is the type of mammogram that checks you when you have no symptoms. It can help reduce the number of deaths from breast cancer among women ages 40 to 70. But it can also have drawbacks. Mammograms can sometimes find something that looks abnormal but isn't cancer. This leads to further testing and can cause you anxiety. Sometimes mammograms can miss cancer when it is there. It also exposes you to radiation. You should talk to your doctor about the benefits and drawbacks of mammograms. Together, you can decide when to start and how often to have a mammogram.

Mammograms are also recommended for younger women who have symptoms of breast cancer or who have a high risk of the disease.

When you have a mammogram, you stand in front of an x-ray machine. The person who takes the x-rays places your breast between two plastic plates. The plates press your breast and make it flat. This may be uncomfortable, but it helps get a clear picture. You should get a written report of your mammogram results within 30 days.

A mammogram is an x-ray picture of the breast.

Mammograms can be used to check for breast cancer in women who have no signs or symptoms of the disease. This type of mammogram is called a screening mammogram. Screening mammograms usually involve two or more x-ray pictures, or images, of each breast. The x-ray images often make it possible to detect tumors that cannot be felt. Screening mammograms can also find microcalcifications (tiny deposits of calcium) that sometimes indicate the presence of breast cancer.

Mammograms can also be used to check for breast cancer after a lump or other sign or symptom of the disease has been found. This type of mammogram is called a diagnostic mammogram. Besides a lump, signs of breast cancer can include breast pain, thickening of the skin of the breast, nipple discharge, or a change in breast size or shape; however, these signs may also be signs of benign conditions. A diagnostic mammogram can also be used to evaluate changes found during a screening mammogram or to view breast tissue when it is difficult to obtain a screening mammogram because of special circumstances, such as the presence of breast implants.

A mammogram is an X-ray picture of the breast. Doctors use a mammogram to look for early signs of breast cancer. Regular mammograms are the best tests doctors have to find breast cancer early, sometimes up to three years before it can be felt.

How is a mammogram done?

You will stand in front of a special X-ray machine. A technologist will place your breast on a plastic plate. Another plate will firmly press your breast from above. The plates will flatten the breast, holding it still while the X-ray is being taken. You will feel some pressure. The steps are repeated to make a side view of the breast. The other breast will be X-rayed in the same way. You will then wait while the technologist checks the four X-rays to make sure the pictures do not need to be re-done. Keep in mind that the technologist cannot tell you the results of your mammogram. Each woman’s mammogram may look a little different because all breasts are a little different.

What does having a mammogram feel like?

Having a mammogram is uncomfortable for most women. Some women find it painful. A mammogram takes only a few moments, though, and the discomfort is over soon. What you feel depends on the skill of the technologist, the size of your breasts, and how much they need to be pressed. Your breasts may be more sensitive if you are about to get or have your period. A doctor with special training, called a radiologist, will read the mammogram. He or she will look at the X-ray for early signs of breast cancer or other problems.

When will I get the results of my mammogram?

You will usually get the results within a few weeks, although it depends on the facility. A radiologist reads your mammogram and then reports the results to you and your doctor. If there is a concern, you will hear from the mammography facility earlier. Contact your health care provider or the mammography facility if you do not receive a report of your results within 30 days.

What happens if my mammogram is normal?

Continue to get mammograms according to recommended time intervals. Mammograms work best when they can be compared with previous ones. This allows the radiologist to compare them to look for changes in your breasts.

What happens if my mammogram is abnormal?

An abnormal mammogram does not always mean that there is cancer. But you will need to have additional mammograms, tests, or exams before the doctor can tell for sure. You may also be referred to a breast specialist or a surgeon. It does not necessarily mean you have cancer or need surgery. These doctors are experts in diagnosing breast problems. Doctors will do follow-up tests to diagnose breast cancer or to find that there is no cancer.

What is mammography?

Mammography is an x-ray imaging method used to examine the breast for the early detection of cancer and other breast diseases. It is used as both a diagnostic and screening tool.

How does it work?

During a mammogram, a patient’s breast is placed on a flat support plate and compressed with a parallel plate called a paddle. An x-ray machine produces a small burst of x-rays that pass through the breast to a detector located on the opposite side. The detector can be either a photographic film plate, which captures the x-ray image on film, or a solid-state detector, which transmits electronic signals to a computer to form a digital image. The images produced are called mammograms.

On a film mammogram, low density tissues, such as fat, appear translucent (i.e. darker shades of gray approaching the black background)., whereas areas of dense tissue, such as connective and glandular tissue or tumors, appear whiter on a gray background. In a standard mammogram, both a top and a side view are taken of each breast, although extra views may be taken if the physician is concerned about a suspicious area of the breast.

What will the results look like?

A radiologist will carefully examine a mammogram to search for high density regions or areas of unusual configuration that look different from normal tissue. These areas could represent many different types of abnormalities, including cancerous tumors, non-cancerous masses called benign tumors, fibroadenomas, or complex cysts. Radiologists look at the size, shape, and contrast of an abnormal region, as well as the appearance of the edges or margins of such an area, all of which can indicate the possibility of malignancy (i.e. cancer). They also look for tiny bits of calcium, called microcalcifications, which show up as very bright specks on a mammogram. While usually benign, sites of microcalcifications may occasionally signal the presence of a specific type of cancer. If a mammogram shows one or more suspicious regions that are not definitive for cancer, the radiologist may order additional mammogram views, with or without additional magnification or compression, or they may order a biopsy. Another alternative may be referral for another type of non-invasive imaging study.

Why does the breast need to be compressed?

Compression holds the breast in place to minimize blurring of the x-ray image that can be caused by patient motion. Also, compression evens out the shape of the breast so that the x-rays can travel through a shorter path to reach the detector. This reduces the radiation dose and improves the quality of the x-ray image. Finally, compression allows all the tissues to be visualized in a single plane so that small abnormalities are less likely to be obscured by overlying breast tissue.

What is digital mammography?

A digital mammogram uses the same x-ray technology as conventional mammograms, but instead of using film, solid-state detectors are used to record the x-ray pattern passing through the breast. These detectors convert the x-rays that pass through them into electronic signals that are sent to a computer. The computer then converts these electronic signals into images that can be displayed on a monitor and also stored for later use. Several advantages of using digital mammography over film mammography include: the ability to manipulate the image contrast for better clarity, the ability to use computer-aided detection of abnormalities, and the ability to easily transmit digital files to other experts for a second opinion. In addition, digital mammograms may decrease the need for the re-takes, which are common with film mammography due to incorrect exposure techniques or problems with film development. As a result, digital mammography can lead to lower x-ray exposures. To date, there is no evidence that digital mammographyis better that film mammography for reducing a woman’s risk of dying from breast cancer, however, digital screening may be more accurate for finding cancers in younger women or women with dense breasts.

What are the limits of mammography?

For certain types of breasts, mammograms can be difficult to interpret. This is because there is a wide variation in breast tissue density among women. Denser breasts are more difficult to image, and more difficult to assess for tumor diagnosis. For this and other reasons, the sensitivity of mammography in detecting cancer can vary over a wide range.

For many difficult cases, x-ray mammography alone may not be sufficiently sensitive or accurate in detecting cancer, so additional imaging technologies, such as ultrasound or magnetic resonance imaging (MRI) may also be used to increase the sensitivity of the exam. Recently, studies have shown that a type of nuclear medicine called molecular breast imaging (MBI) may be an effective and less expensive alternative to MRI for clarifying test results in patients with dense breasts. During MBI, patients are given an injection of radioactive molecules that are selectively taken up by cancer cells. Special cameras that detect radioactivity are then used to reveal these cancer cells in the breast tissue.

Are there risks?

Because mammography uses x-rays to produce images of the breast, patients are exposed to a small amount of ionizing radiation. For most women, the benefits of regular mammograms outweigh the risks posed by this amount of radiation. The risk associated with this dose appears to be greater among younger women (under age 40). However, in some cases, the benefits of using mammography to detect breast cancer under age 40 may outweigh the risks of radiation exposure. For example, a mammogram may reveal that a suspicious mass is benign and, therefore, doesn’t need to be treated. Additionally, if a tumor is malignant and is caught early by mammogram, a surgeon may be able to remove it before it spreads and requires more aggressive treatment such as chemotherapy.

When should I get a mammogram?

Several organizations and professional societies have developed guidelines for mammographyscreening. You can read more about these recommendations on their websites below. All recommend that women talk with their doctor about the benefits and potential harms of mammography, when to start screening, and how often to be screened.

What are examples of NIBIB-funded projects in breast cancer screening?

Dedicated Breast CT: Research funded by NIBIB has led to the development of a breast CT scanner (bCT) that allows radiologists to view the breast in three dimensions and has the potential to reveal small tumors obscured behind dense breast tissue. The scanner uses a radiation dose comparable to mammography by sending X-rays only through the breast and not the chest. At present, more than 600 women have been imaged using bCT in clinical trials. Results from these trials suggest that bCT is significantly better at detecting tumors than mammography, though mammography is better at detecting microcalcifications. Recently, positron emission tomography (PET) technology has been incorporated into the bCT platform. A PET scan highlights areas of increased metabolic activity, which could indicate the presence of a tumor. Additionally, injection of a contrast agent has been shown to improve bCT’s ability to detect microcalcifications and could help radiologists distinguish benign from malignant tumors. Research is currently focused on ways in which bCT could be used to provide real-time image guidance for biopsy needle placement and minimally invasive ablation of tumors.

Near-Infrared, Diffuse Light Imaging with Ultrasonic Guidance:Researchers funded by NIBIB have developed a novel, hand-held breast imaging system that uses visible light to distinguish benign lesions from early-stage cancer. The system creates maps of tissue density in a local area of the breast based on how the tissue scatters light; the denser the tissue, the more light is scattered, and the greater the likelihood that the tissue is cancerous. The method is currently being tested in a large number of patients undergoing surgery to remove a breast tumor. Early results indicate that the imaging system may be a promising adjunct to mammographyfor diagnosing breast cancer and determining disease prognosis. In addition, the system could allow surgeons to more rapidly determine tumor margins during surgery compared to methods used over the past twenty years. This could potentially reduce surgeries that need to be repeated because not all cancerous tissue was removed initially.

Screening mammograms are done for women who have no symptoms of breast cancer. It usually involves two x-rays of each breast. Screening mammograms can detect lumps or tumors that cannot be felt. They can also find microcalcifications (my-kro-kal-si-fi-KAY-shuns) or tiny deposits of calcium in the breast, which sometimes mean that breast cancer is present.

Diagnostic mammograms are used to check for breast cancer after a lump or other symptom or sign of breast cancer has been found. Signs of breast cancer may include pain, thickened skin on the breast, nipple discharge, or a change in breast size or shape. This type of mammogram also can be used to find out more about breast changes found on a screening mammogram, or to view breast tissue that is hard to see on a screening mammogram. A diagnostic mammogram takes longer than a screening mammogram because it involves more x-rays in order to obtain views of the breast from several angles. The technician can magnify a problem area to make a more detailed picture, which helps the doctor make a correct diagnosis.

A digital mammogram also uses x-rays to produce an image of the breast, but instead of storing the image directly on film, the image is stored directly on a computer. This allows the recorded image to be magnified for the doctor to take a closer look. Current research has not shown that digital images are better at showing cancer than x-ray film images in general. But, women with dense breasts who are pre- or perimenopausal, or who are younger than age 50, may benefit from having a digital rather than a film mammogram. Digital mammography may offer these benefits:

• Long-distance consultations with other doctors may be easier because the images can be shared by computer.
• Slight differences between normal and abnormal tissues may be more easily noted.
• The number of follow-up tests needed may be fewer.
• Fewer repeat images may be needed, reducing exposure to radiation.

In the United States, digital mammography has replaced conventional mammography. Digital and conventional mammography both use x-rays to produce an image of the breast; however, in conventional mammography, the image is stored directly on film, whereas, in digital mammography, an electronic image of the breast is stored as a computer file. This digital information can be enhanced, magnified, or manipulated for further evaluation more easily than information stored on film. Digital images can also be shared electronically, making virtual (remote) consultations between radiologists and breast surgeons easier.

Digital mammography can be done only in facilities that are certified to practice conventional mammography and have received FDA approval to offer digital mammography. The procedure for having a mammogram with a digital system is the same as with conventional mammography.

What is digital mammography?

Full field digital mammography (FFDM, also known simply as "digital mammography") is a mammography system where the x-ray film used in screen-film mammography is replaced by solid-state detectors, similar to those found in digital cameras, which convert x-rays into electrical signals. The electrical signals are used to produce images of the breast that can be seen on a computer screen, or printed on special films to look like screen-film mammograms. Types of digital mammography include direct radiography (the most common type, which captures the image directly onto a flat-panel detector), computed radiography (which involves the use of a cassette that contains an imaging plate), or digital breast tomosynthesis (DBT).

What is DBT?

Digital breast tomosynthesis is a relatively new technology. In DBT, the X-ray tube moves in an arc around the breast and takes multiple images from different angles. Similar to computed tomography (CT scan), these images are then reconstructed into parallel “slices” through the breast. This allows interpreting physicians to see through layers of overlapping tissue.

How can women find an FDA-certified digital mammography facility?

Digital mammography has been in use since 2001. Over ninety-nine percent of all certified mammography facilities in the US use digital units of some type. You can find a list of certified facilities, searchable by state or ZIP Code, at www.fda.gov/findmammography.

Do private insurance companies, Medicare and Medicaid pay for digital mammography exams, such as DBT?

We recommend that you contact your insurance provider before the procedure to determine what procedures are covered by your insurance plan. The telephone number for questions about Medicare reimbursement is 1-800-MEDICARE. To find the number for MEDICAID, look in your local directory.

A high-quality mammogram plus a clinical breast exam, an exam done by your doctor, is the most effective way to detect breast cancer early. Finding breast cancer early greatly improves a woman's chances for successful treatment.

Like any test, mammograms have both benefits and limitations. For example, some cancers can't be found by a mammogram, but they may be found in a clinical breast exam.

Checking your own breasts for lumps or other changes is called a breast self-exam (BSE). Studies so far have not shown that BSE alone helps reduce the number of deaths from breast cancer. BSE should not take the place of routine clinical breast exams and mammograms.

If you choose to do BSE, remember that breast changes can occur because of pregnancy, aging, menopause, menstrual cycles, or from taking birth control pills or other hormones. It is normal for breasts to feel a little lumpy and uneven. Also, it is common for breasts to be swollen and tender right before or during a menstrual period. If you notice any unusual changes in your breasts, contact your doctor.

The United States Preventive Services Task Force (USPSTF) recommends:

• Women ages 50 to 74 years should get a mammogram every 2 years.
• Women younger than age 50 should talk to a doctor about when to start and how often to have a mammogram.

You stand in front of a special x-ray machine. The person who takes the x-rays, called a radiologic technician, places your breasts, one at a time, between an x-ray plate and a plastic plate. These plates are attached to the x-ray machine and compress the breasts to flatten them. This spreads the breast tissue out to obtain a clearer picture. You will feel pressure on your breast for a few seconds. It may cause you some discomfort; you might feel squeezed or pinched. This feeling only lasts for a few seconds, and the flatter your breast, the better the picture. Most often, two pictures are taken of each breast — one from the side and one from above. A screening mammogram takes about 20 minutes from start to finish.

The radiologist will look at your x-rays for breast changes that do not look normal and for differences in each breast. He or she will compare your past mammograms with your most recent one to check for changes. The doctor will also look for lumps and calcifications.

• Lump or mass. The size, shape, and edges of a lump sometimes can give doctors information about whether or not it may be cancer. On a mammogram, a growth that is benign often looks smooth and round with a clear, defined edge. Breast cancer often has a jagged outline and an irregular shape.
• Calcification. A calcification is a deposit of the mineral calcium in the breast tissue. Calcifications appear as small white spots on a mammogram. There are two types:
  
  • Macrocalcifications are large calcium deposits often caused by aging. These usually are not a sign of cancer.
  • Microcalcifications are tiny specks of calcium that may be found in an area of rapidly dividing cells.

If calcifications are grouped together in a certain way, it may be a sign of cancer. Depending on how many calcium specks you have, how big they are, and what they look like, your doctor may suggest that you have other tests. Calcium in the diet does not create calcium deposits, or calcifications, in the breast.

Early detection of breast cancer with screening mammography means that treatment can be started earlier in the course of the disease, possibly before it has spread. Results from randomized clinical trials and other studies show that screening mammography can help reduce the number of deaths from breast cancer among women ages 40 to 74, especially for those over age 50 (1). However, studies to date have not shown a benefit from regular screening mammography in women under age 40 or from baseline screening mammograms (mammograms used for comparison) taken before age 40.

The benefits of screening mammography need to be balanced against its harms, which include:

False-positive results. False-positive results occur when radiologists see an abnormality (that is, a potential “positive”) on a mammogram but no cancer is actually present. All abnormal mammograms should be followed up with additional testing (diagnostic mammograms, ultrasound, and/or biopsy) to determine whether cancer is present.

False-positive mammogram results can lead to anxiety and other forms of psychological distress in affected women. The additional testing required to rule out cancer can also be costly and time consuming and can cause physical discomfort.

False-positive results are more common for younger women, women with dense breasts, women who have had previous breast biopsies, women with a family history of breast cancer, and women who are taking estrogen (for example, menopausal hormone therapy). The chance of having a false-positive result increases with the number of mammograms a woman has. More than 50% of women screened annually for 10 years in the United States will experience a false-positive result, and many of these women will have a biopsy.

Overdiagnosis and overtreatment. Screening mammograms can find cancers and cases of ductal carcinoma in situ (DCIS, a noninvasive tumor in which abnormal cells that may become cancerous build up in the lining of breast ducts) that need to be treated. However, they can also find cases of DCIS and small cancers that would never cause symptoms or threaten a woman’s life. This phenomenon is called "overdiagnosis." Treatment of overdiagnosed cancers and overdiagnosed cases of DCIS is not needed and results in "overtreatment."

Because doctors cannot easily distinguish cancers and cases of DCIS that need to be treated from those that do not, they are all treated.

False-negative results. In cancer screening, a negative result means no abnormality is present. False-negative results occur when mammograms appear normal even though breast cancer is present. Overall, screening mammograms miss about 20% of breast cancers that are present at the time of screening. False-negative results can lead to delays in treatment and a false sense of security for affected women.

One cause of false-negative results is high breast density. Breasts contain both dense tissue (i.e., glandular tissue and connective tissue, together known as fibroglandular tissue) and fatty tissue. Fatty tissue appears dark on a mammogram, whereas fibroglandular tissue appears as white areas. Because fibroglandular tissue and tumors have similar density, tumors can be harder to detect in women with denser breasts.

False-negative results occur more often among younger women than among older women because younger women are more likely to have dense breasts. As a woman ages, her breasts usually become more fatty, and false-negative results become less likely.

Some breast cancers grow so quickly that they appear within months of a normal (negative) screening mammogram. This situation does not represent a false-negative result, because the negative result of the screening was correct. But it means that a negative result can give a false sense of security. Some of the cancers missed by screening mammograms can be detected by clinical breast exams (physical exams of the breast done by a health care provider).

Finding breast cancer early may not reduce a woman’s chance of dying from the disease. Even though mammograms can detect malignant tumors that cannot be felt, treating a small tumor does not always mean that the woman will not die from the cancer. A fast-growing or aggressive cancer may have already spread to other parts of the body before it is detected. Instead, women with such tumors live a longer period of time knowing that they likely have a potentially fatal disease.

In addition, finding breast cancer early may not help prolong the life of a woman who is suffering from other, more life-threatening health conditions.

Radiation exposure. Mammograms require very small doses of radiation. The risk of harm from this radiation exposure is low, but repeated x-rays have the potential to cause cancer. Although the potential benefits of mammography nearly always outweigh the potential harm from the radiation exposure, women should talk with their health care providers about the need for each x-ray. In addition, they should always let their health care provider and the x-ray technologist know if there is any possibility that they are pregnant, because radiation can harm a growing fetus.

Although they are not perfect, mammograms are the best method to find breast changes that cannot be felt. If your mammogram shows a breast change, sometimes other tests are needed to better understand it. Even if the doctor sees something on the mammogram, it does not mean it is cancer.

As with any medical test, mammograms have limits. These limits include:

• They are only part of a complete breast exam. Your doctor also should do a clinical breast exam. If your mammogram finds something abnormal, your doctor will order other tests.
• Finding cancer does not always mean saving lives. Even though mammography can detect tumors that cannot be felt, finding a small tumor does not always mean that a woman's life will be saved. Mammography may not help a woman with a fast growing cancer that has already spread to other parts of her body before being found.
• False negatives can happen. This means everything may look normal, but cancer is actually present. False negatives don't happen often. Younger women are more likely to have a false negative mammogram than are older women. The dense breasts of younger women make breast cancers harder to find in mammograms.
• False positives can happen. This is when the mammogram results look like cancer is present, even though it is not. False positives are more common in younger women, women who have had breast biopsies, women with a family history of breast cancer, and women who are taking estrogen, such as menopausal hormone therapy.
• Mammograms (as well as dental x-rays and other routine x-rays) use very small doses of radiation. The risk of any harm is very slight, but repeated x-rays could cause cancer. The benefits nearly always outweigh the risk. Talk to your doctor about the need for each x-ray. Ask about shielding to protect parts of the body that are not in the picture. You should always let your doctor and the technician know if there is any chance that you are pregnant.

First, check with the place you are having the mammogram for any special instructions you may need to follow before you go. Here are some general guidelines to follow:

• If you are still having menstrual periods, try to avoid making your mammogram appointment during the week before your period. Your breasts will be less tender and swollen. The mammogram will hurt less and the picture will be better.
• If you have breast implants, be sure to tell your mammography facility that you have them when you make your appointment.
• Wear a shirt with shorts, pants, or a skirt. This way, you can undress from the waist up and leave your shorts, pants, or skirt on when you get your mammogram.
• Don't wear any deodorant, perfume, lotion, or powder under your arms or on your breasts on the day of your mammogram appointment. These things can make shadows show up on your mammogram.
• If you have had mammograms at another facility, have those x-ray films sent to the new facility so that they can be compared to the new films.

Digital Breast Tomosynthesis, also known as 3D mammography, is an FDA-approved method for breast cancer screening in which x-rays of the breast are taken at different angles to generate thin cross-sections. The 3D representation of the breast is similar to the 3d images created by standard CT technology. Tomosynthesis differs from CT technology in that significantly fewer x-ray beams are projected through the breast than with CT and the x-ray exposure to the rest of the chest is dramatically reduced. Hence, the radiation dose delivered to the breast by tomosynthesis is similar to that delivered 2D mammography. While tomosynthesis uses very low-dose x-rays, it is currently most often used in addition to 2D mammography, making the total radiation dose higher than standard mammography. Early evaluations of 3D mammography suggest an improved detection of breast cancers than seen with 2D mammography, but extensive large-scale comparisons of tomosynthesis with 2D mammography in randomized studies are still in process. Therefore, researchers do not know with full certainty whether 3D mammography is better or worse than standard mammography at avoiding false-positive results and identifying early cancers in all types of patients.

Three-dimensional (3-D) mammography, also known as digital breast tomosynthesis (DBT), is a type of digital mammography in which x-ray machines are used to take pictures of thin "slices" of the breast from different angles and computer software is used to reconstruct an image. This process is similar to how a computed tomography (CT) scanner produces images of structures inside of the body. 3-D mammography uses very low dose x-rays, but, because it is generally performed at the same time as standard two-dimensional (2-D) digital mammography, the radiation dose is higher than that of standard mammography. Newer tomosynthesis strategies allow DBT to be done alone, potentially reducing the radiation dose to a level closer to that of standard mammography.

Although many women are offered DBT, it has not yet been determined conclusively whether it is superior to 2-D mammography at identifying early cancers and avoiding false-positive results.

A large-scale randomized breast screening trial is comparing 3-D mammography with 2-D mammography. The Tomosynthesis Mammography Imaging Screening Trial (TMIST) is comparing the number of advanced cancers detected in women screened for 4 years with DBT with that detected in women screened with standard digital mammography.

Women with breast implants should also have mammograms. A woman who had an implant after breast cancer surgery in which the entire breast was removed (mastectomy) should ask her doctor whether she needs a mammogram of the reconstructed breast.

If you have breast implants, be sure to tell your mammography facility that you have them when you make your appointment. The technician and radiologist must be experienced in x-raying patients with breast implants. Implants can hide some breast tissue, making it harder for the radiologist to see a problem when looking at your mammogram. To see as much breast tissue as possible, the x-ray technician will gently lift the breast tissue slightly away from the implant and take extra pictures of the breasts.

The American College of Radiology (ACR) has established a uniform way for radiologists to describe mammogram findings. The system, called BI-RADS, includes seven standardized categories, or levels. Each BI-RADS category has a follow-up plan associated with it to help radiologists and other physicians appropriately manage a patient’s care.

Breast Imaging Reporting and Database System (BI-RADS)

BI-RADS also includes four categories of breast density that may be reported. The radiologist who reads the mammogram chooses the category that best describes the level of breast density seen on the mammogram film. The categories, from the least amount of breast density to the highest, are as follows:

• The breasts are almost entirely fatty
• There are scattered areas of dense glandular tissue and fibrous connective tissue (together known as fibroglandular density)
• The breasts are heterogeneously dense, which means they have more of these areas of fibroglandular density. This may make it hard to see small masses in the breast tissue on a mammogram.
• The breasts are extremely dense, which makes it hard to see tumors in the breast tissue on a mammogram.

Many states in the U.S. have enacted laws requiring mammography providers to tell women if they have dense breasts (i.e., breasts that are heterogeneously or extremely dense on a mammogram) and to inform them of risks associated with having dense breasts. In addition to making mammograms harder to read, dense breasts are a risk factor for breast cancer.

If you have a screening test result that suggests cancer, your doctor must find out whether it is due to cancer or to some other cause. Your doctor may ask about your personal and family medical history. You may have a physical exam. Your doctor also may order some of these tests:

• Diagnostic mammogram, to focus on a specific area of the breast
• Ultrasound, an imaging test that uses sound waves to create a picture of your breast. The pictures may show whether a lump is solid or filled with fluid. A cyst is a fluid-filled sac. Cysts are not cancer. But a solid mass may be cancer. After the test, your doctor can store the pictures on video or print them out. This exam may be used along with a mammogram.
• Magnetic resonance imaging (MRI), which uses a powerful magnet linked to a computer. MRI makes detailed pictures of breast tissue. Your doctor can view these pictures on a monitor or print them on film. MRI may be used along with a mammogram.
• Biopsy, a test in which fluid or tissue is removed from your breast to help find out if there is cancer. Your doctor may refer you to a surgeon or to a doctor who is an expert in breast disease for a biopsy.

A mammogram is an x-ray picture of the breast to check for breast cancer. Mammograms can help find breast cancer early, before it spreads to other parts of the body. Most women can survive breast cancer if it’s found and treated early.

• If you are age 40 to 49, talk with your doctor about when to start getting mammograms and how often to get them.
• If you are age 50 to 74, get mammograms every 2 years. You may also choose to get them more often.

Together, you and your doctor can decide what’s best for you.

The Affordable Care Act requires most health plans to cover mammograms for women over age 40. Depending on your insurance plan, you may be able to get mammograms at no cost to you. Talk to your insurance company to learn more.

Like all medical tests, mammograms have pros and cons. These pros and cons depend on your age and your risk for breast cancer. Use the questions below to start a conversation with your doctor about mammograms.

What do I ask the doctor?

Visiting the doctor can be stressful. It helps to have questions for the doctor written down ahead of time. Print this list of questions and take it with you to your next appointment. You may also want to ask a family member or close friend to go with you to take notes.

• Do I have any risk factors that increase my chances of getting breast cancer?
• What will happen when I go to get mammograms?
• How long will it take to get the results of my mammograms?
• If I don’t hear back about the results of my mammograms, does that mean everything is okay?

If you are under age 50, you might want to ask:

• Should I start getting regular mammograms? If so, how often?
• What are the pros and cons of getting mammograms before age 50?

If you are age 50 to 74, you might want to ask:

• How often should I get mammograms?
• What are the pros and cons of getting mammograms every 2 years instead of every year?