Few new technologies are there to screen the breast cancer. Mammography is the current standard test for breast cancer screening. MRI is also recommended along with mammograms for some women at high risk for breast cancer. Other tests, such as ultrasound, are now being studied as well.
Magnetic resonance imaging (MRI): For certain women at high risk for breast cancer, screening MRI is recommended along with a yearly mammogram. MRI is not generally recommended as a screening tool by itself, as it may miss some cancers that mammograms would detect.
MRI uses magnets and radio waves, instead of x-rays, to produce very detailed, cross-sectional images of the body. The most useful MRI exams for breast imaging use a contrast material (gadolinium DTPA) that is injected into a small vein in the arm before or during the exam. This improves the ability of the MRI to clearly show breast tissue details.
MRI is also more expensive than mammography. Most major insurance companies will likely pay for these screening tests if a woman can be shown to be at high risk, but it’s not yet clear if all companies will. At this time there are concerns about costs of and limited access to high-quality MRI breast screening services for women at high risk of breast cancer.
Breast ultrasound: Ultrasound, also known as sonography, is an imaging method in which high-frequency sound waves are used to look inside a part of the body. A handheld instrument placed on the skin transmits the sound waves through the breast. Echoes from the sound waves are picked up and translated by a computer into an image that is displayed on a computer screen. You are not exposed to radiation during this test.
Breast ultrasound is sometimes used to evaluate breast problems that are found during a screening or diagnostic mammogram or on physical exam. Breast ultrasound is not routinely used for screening. Some studies have suggested that ultrasound may be a helpful addition to mammography when screening women with dense breast tissue (which is hard to evaluate with a mammogram), but the use of ultrasound instead of mammograms is not recommended.
Ultrasound is useful for evaluating some breast masses and is the only way to tell if a suspicious area is a cyst without placing a needle into it to aspirate (pull out) fluid. Cysts cannot be accurately diagnosed by physical exam alone. Breast ultrasound may also be used to help doctors guide a biopsy needle into some breast lesions.
Ductogram: This test, also called a galactogram, is sometimes helpful in determining the cause of bloody nipple discharge. In this test a thin plastic tube is placed into the opening of the duct at the nipple. A small amount of contrast medium is injected that outlines the shape of the duct on an x-ray image, which will show if there is a mass inside the duct.
Full-field digital mammograms (FFDM): Full field digital mammography is similar to standard mammography in that x-rays are used to produce an image of your breast. The differences are in the way the image is recorded, viewed by the doctor, and stored. Standard mammograms are recorded on large sheets of photographic film. Digital mammograms are recorded and stored on a computer. After the exam, the doctor can view them on a computer screen and adjust the image size, brightness, or contrast to see certain areas more clearly. Digital images can also be sent electronically to another site for a remote consult with breast specialists. While many centers do not offer the digital option at this time, it is expected to become more widely available in the future.
Because digital mammograms cost more than standard mammograms, studies are now under way to determine which form of mammogram will benefit more women in the long run. Some studies have found that women who have FFDM have to return less often for additional imaging tests because of inconclusive areas on the original mammogram. A recent large study from the National Cancer Institute found that FFDM was more accurate in finding cancers in women younger than 50 and in women with dense breast tissue, although the rates of inconclusive results were similar between FFDM and film mammography. It is important to remember that standard film mammography also is effective for these groups of women, and that they should not miss their regular mammogram if digital mammography is not available.
Computer-aided detection and diagnosis (CAD): Over the past 2 decades, computer-aided detection and diagnosis (CAD) has been developed to help radiologists detect suspicious changes on mammograms. This is done most commonly with screen-film mammograms and less often with digital mammograms. Generally the computer device will scan the mammogram first. It can find tumors that the radiologist can’t spot. The radiologist, knowing the results of the CAD, will then review the films to look for lesions the CAD missed. The radiologist will then decide the seriousness of the lesions the CAD found. Early research results suggest that CAD systems help radiologists diagnose more early stage cancers than mammograms alone.
Scintimammography: In scintimammography, a radioactive tracer is injected into a vein to detect breast cancer cells. The tracer attaches to breast cancers and is detected by a special camera. This is a very new technique and is still considered experimental. It may or may not be helpful in evaluating abnormal mammograms.
For more information about these and other breast imaging tests, see the American Cancer Society document, “Mammograms and Other Breast Imaging Procedures.”
If you think you are at higher risk for developing breast cancer, talk to your doctor about what is known about these tests and their potential benefits, limitations, and harms. Then make a decision together about what is best for you.
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