Mammograms and Other Breast Imaging Tests

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Experimental and other breast imaging methods

Research in the field of breast imaging is being done to

  • Find more cancers even before they can be felt by the patient or her doctor
  • Find even smaller cancers than those now detected by mammograms
  • Find better ways to tell the difference between benign (not cancer) breast conditions and breast cancers

Tests being developed for these purposes need more study before their usefulness can be determined. Even though some of these imaging tests have been FDA approved for use along with mammography and other proven test methods, their place in the diagnosis or screening of breast cancer is less clear-cut.

Nuclear medicine studies

For nuclear medicine studies (also called nuclear scans) small amounts of slightly radioactive substances are injected into the body and special cameras are used to see where they go. Depending on the substance used, different types of abnormalities may be found. Unlike most other imaging tests that are based on changes tumors cause in the body’s structure, nuclear medicine scans depend on changes in tissue metabolism. A couple of newer subtypes of nuclear medicine studies are described below under “Other experimental breast imaging tests.”

Scintimammography (molecular breast imaging)

A radioactive tracer known as technetium sestamibi has been studied to help detect breast cancer. For this test, a small amount of the radioactive tracer is put into a vein. The tracer attaches to breast cancer cells and is detected by a special camera.

This test is not used as a screening test. Some radiologists believe this test may be helpful in looking at suspicious areas found by mammogram. But the exact role of scintimammography is still unclear.

Current research is aimed at improving the technology and evaluating its use in specific situations, such as in the dense breasts of younger women. Some early studies have suggested that it may be almost as accurate as more expensive MRI scans. More research is needed.

Electrical impedance imaging (T-scan™)

Electrical impedance imaging (EIT) scans the breast for electrical conductivity. It’s based on the idea that breast cancer cells conduct electricity in a different way than normal cells. The test passes a very small electrical current through the breast and then detects it on the skin of the breast. This is done using small electrodes that are taped to the skin. EIT does not use radiation or compress the breasts.

This test is FDA approved as a diagnostic aid in helping classify tumors found on mammogram. But at this time it has not had enough clinical testing to be used in breast cancer screening.

Thermography (thermal imaging)

Thermography is a way to measure and map the heat on the surface of the breast using a special heat-sensing camera. It’s based on the idea that the temperature rises in areas with increased blood flow and metabolism, which could be a sign of a tumor.

Thermography has been around for many years, but studies have shown that it’s not an effective screening tool for finding breast cancer early. Although it has been promoted as helping detect breast cancer early, a 2012 research review found that thermography was able to detect only a quarter of the breast cancers found by mammography. In other words, it failed to detect 3 out of 4 cancers that were known to be present in the breast. Digital infrared thermal imaging (DITI), which some people believe is a newer and better type of thermography, has the same failure rate. This is why thermography should not be used as a substitute for mammograms.

Other experimental breast imaging tests

Some newer techniques are now being studied for breast imaging. These tests are in the earliest stages of research. It will take time to see if any of these imaging tests are as good as or better than those we use today.

Optical imaging tests pass light into the breast and then measure the light that returns or passes through the tissue. The technique does not use radiation and does not require breast compression. Optical imaging might be useful at some point for detecting tumors or the blood vessels that supply them.

Molecular breast imaging (MBI) is a new nuclear medicine imaging technique for the breast. It’s being tested to see if it may be a less expensive and more specific way to identify breast changes that have been seen on a mammogram or ultrasound. At this time it’s still in the early research stages.

Positron Emission Mammography (PEM) is another newly developed imaging exam of the breast. It uses sugar attached to a radioactive particle to detect cancer cells. The PEM scanner is FDA approved. Working much like a PET scan, a PEM scan may be better able to detect clusters of cancer cells within the breast. PEM may be able to show breast cancer before it can be seen with mammograms and might prove to be as good as or better than breast MRI. A number of studies are under way to assess this.

Last Medical Review: 12/10/2013
Last Revised: 11/05/2014