Newer and Experimental Breast Imaging Tests

The most commonly used breast imaging tests at this time are mammograms, ultrasound, and breast MRI. Other tests, such as CT scans, bone scans, or PET scans might sometimes be done to help find out if breast cancer has spread.

Newer types of tests are now being developed for breast imaging. Some of these, such as breast tomosynthesis (3D mammography), are already being used in some centers. Other tests are still being studied, and it will take time to see if they are as good as or better than those used today.

Abbreviated breast MRI (fast breast MRI) 

This is a newer technique that is done with a standard breast MRI scanner. But fewer images are taken (over a shorter period of time) than with a standard breast MRI. As with standard breast MRI, a contrast material called gadolinium is given through an IV line before some of the images are taken. Abbreviated breast MRI is now being studied as a possible screening test for breast cancer, especially in women with dense breasts, to see if it provides the same information as a standard breast MRI.

Nuclear medicine tests (radionuclide imaging)

For these tests, a small amount of radioactive material (known as a tracer) is injected into the blood. The tracer is more likely to collect in cancer cells. A special camera can then be used to see the tracer in the breast (or other parts of the body).

For molecular breast imaging (MBI), also known as scintimammography or breast-specific gamma imaging (BSGI), a tracer called technetium-99m sestamibi is injected into the blood, and a special camera is then used to see the tracer while the breast is gently compressed. This test is being studied mainly as a way to follow up breast problems (such as a lump or an abnormal mammogram), or to help determine the extent of breast cancer that has already been diagnosed. It’s also being studied as a screening test for use along with mammograms to look for cancer in women with dense breasts. One potential drawback is that it exposes the whole body to radiation, so it’s unlikely this test would be used for screening every year.

For a positron emission tomography (PET) scan, a different type of radioactive tracer is injected into the blood. Standard PET scans, which use a form of radioactive sugar (known as FDG), are sometimes done if there's a concern that breast cancer might have spread to other parts of the body. A newer type of tracer, known as fluoroestradiol F-18, is now available to look for the spread of some advanced estrogen receptor (ER)-positive breast cancers. 

Positron emission mammography (PEM) is a newer imaging test of the breast that combines some aspects of a PET scan and a mammogram. PEM uses the same type of radioactive tracer injected into the blood as a PET scan. The breast is then lightly compressed while the images are taken, as with a mammogram. PEM may be better able to detect small clusters of cancer cells within the breast than standard mammography. This is because it takes into account how active the breast cells are, as opposed to just their structure. PEM is being studied mainly in women with breast cancer to see if it can help determine the extent of the cancer. PEM exposes the whole body to radiation, so it isn't likely to be used every year for breast cancer screening.

Contrast-enhanced mammography (CEM)

Also known as contrast-enhanced spectral mammography (CESM), this is a newer test in which a contrast dye containing iodine is injected into the blood a few minutes before two sets of mammograms (using different energy levels) are taken. The contrast can help the x-rays show any abnormal areas in the breasts. This test can be used to get a better look at areas that appear abnormal on a standard mammogram, or to help assess the extent of a tumor in women just diagnosed with breast cancer. Studies are now comparing it to breast MRI in these settings (where it might be particularly useful if MRI can't be done for some reason), as well as possibly for use in screening women with dense breasts. If it proves to be as good as MRI, CEM could become more widely used because it is quicker to do and is less expensive than MRI.

Elastography

This is a test that can be done as part of an ultrasound exam. It’s based on the idea that breast cancer tumors tend to be firmer and stiffer than the surrounding breast tissue. For this technique, the breast is compressed slightly, and the ultrasound can show how firm a suspicious area is. This test might prove to be useful in telling if the area is more likely to be cancer or a benign (non-cancerous) tumor. 

Optical imaging tests

These 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. Early studies going on now are looking at combining optical imaging with other tests like MRI, ultrasound, or 3D mammography to help look for breast cancer.

Electrical impedance tomography (EIT) 

EIT is based on the idea that breast cancer cells conduct electricity differently from normal cells. For this test, small electrodes are taped to the skin to pass very small electrical currents through the breast and then detect them on the skin. EIT does not use radiation or compress the breasts. This test might prove to be useful in helping to classify tumors found on mammograms. But so far there hasn’t been enough clinical testing to show if it's useful for breast cancer screening.