While mammograms are the most useful tests for screening and finding breast cancer early, other imaging tests may be helpful in some cases.
MRI (magnetic resonance imaging)
MRI is used for women who have been diagnosed with breast cancer to help measure the size of the cancer and to look for any other cancers in the breasts. 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 might miss some cancers that a mammogram would detect.
MRI scans use magnets and radio waves instead of x-rays to produce very detailed, cross-sectional pictures of the body. The most useful MRI exams for breast imaging use a contrast material (called gadolinium) that is injected into a vein in the arm before or during the exam. This helps to clearly show breast tissue details.
Just as mammograms are done with x-ray machines that are specially designed to image the breasts, breast MRI also requires special equipment. Breast MRI machines produce higher quality images than MRI machines designed for head, chest, or abdominal scanning. But many hospitals and imaging centers do not have dedicated breast MRI equipment available.
It is important that screening MRIs are only done at facilities that also can do an MRI-guided breast biopsy. Otherwise, the entire scan will need to be repeated at another facility if a biopsy is needed.
MRIs cost more than mammograms. Most major insurance companies pay for these screening tests if a woman can be shown to be at high risk, but it’s a good idea to check with your insurance company before having the test. 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.
When getting ready for a breast MRI, you can eat and drink as usual. You will need to take off clothes with metal parts such as zippers, snaps, or buttons, and put on a gown or top. Jewelry, hairpins, safety pins, and anything else made of metal must be removed before you go into the MRI room. The technologist will ask if you have any metal in your body, such as surgical clips, staples, implanted catheters, pacemakers, artificial joints, metal fragments, tattoos, permanent eyeliner, and so on. Some metal objects will not cause problems, but others might. Tell the staff before the scan if you have any allergies, if you have breast implants, or if you are pregnant or breast-feeding.
You may need to have an IV put in for contrast dye to help outline the structures of the breast. For the actual MRI, you will lie on your stomach on a padded platform with spaces for your breasts. You will need to be very still during the test, which takes about 30 to 45 minutes.
Breast ultrasound
Ultrasound, also known as sonography, uses sound waves to look inside a part of the body. A gel is put on the skin of the breast and a handheld instrument called a transducer is rubbed in the gel and pressed against the skin. The transducer transmits the sound waves through the breast. Echoes from the sound waves are picked up and converted by a computer into a black and white picture that is shown on a computer screen. This test is painless and does not expose you to radiation.
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 used for screening. Some studies have suggested that it may be helpful to use ultrasound along with a mammogram when screening high risk women with dense breast tissue (which is hard to evaluate with a mammogram). But at this time, ultrasounds cannot replace mammograms. More studies are needed to figure out if ultrasound should be added to routine screening mammograms for some groups of women.
Ultrasound is useful for taking a closer look at some breast masses, and it is the only way to tell if a suspicious area is a cyst without putting a needle into it to take out (aspirate) fluid. Breast ultrasound may also be used to help doctors guide a biopsy needle into an area of concern in the breast.
Ultrasound has become a valuable tool to use along with mammograms because it is widely available, non-invasive, and costs less than other options. But the value of an ultrasound test depends on the operator’s level of skill and experience. Although ultrasound is less sensitive than MRI (that is, it detects fewer tumors), it has the advantage of costing less and being more widely available.
Ductogram (galactogram)
A ductogram is a test that is sometimes helpful in finding the cause of a nipple discharge. In this test, a very thin plastic tube is put into the opening of a duct in the nipple that has the discharge coming out of it. A small amount of contrast material is put in. It outlines the shape of the duct on x-ray and shows whether there is a mass inside the duct.
Feedback
