Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI) uses magnetic fields to create an image of the breast. MRI is mostly used in breast cancer diagnosis and staging.

There is growing evidence that MRI in combination with mammography, compared to mammography alone, can increase detection of breast cancer in certain groups of women at high risk. For example, The American Cancer Society and the National Comprehensive Cancer Network currently recommend women with a BRCA1 or BRCA2 genetic mutation get an MRI in combination with their annual mammography screening.

Some finding also suggest that for women diagnosed with cancer in one breast, MRI with mammography can find breast cancer in the opposite breast better than mammography alone. This combination is also under study for screening in women with dense breast tissue.

MRI screenings do have their drawbacks. It’s more invasive than mammography because a contrast agent is given through an IV during the procedure. Like mammography, MRI has false positive results, which require additional follow-up.

Also, not all radiologists are trained to read MRI-images. If there is an abnormal finding detected by an MRI, not all centers have the means to do an MRI-guided biopsy. Lastly, MRI is expensive and not always covered by insurance.

Ultrasound

Ultrasound is the most common follow-up test used in conjunction with an abnormal mammogram. Typically used on pregnant women, the exam uses sound waves to create images of the breast.

Ultrasound is better than mammography at distinguishing dense breast tissue from tumors. Studies have shown that ultrasound combined with mammography can find more breast cancers than mammography alone in women with dense breasts.

Ultrasound is used on young women (under the age of 35) instead of a mammogram if a breast lump is found. This is because young women generally have less fat in their breasts and causes the mammogram to be less sensitive. This also avoids unnecessary radiation exposure.

Studies show ultrasound alone is not a valid breast cancer screening tool. The quality of the image is greatly dependent upon the skill and experience of the technologist; therefore, it is relative and inconsistent.

Tomosynthesis (3D digital mammography)

Advances in digital mammography machines and software can create a 3D X-ray image of the breast (called breast tomosynthesis). The machine takes multiple two-dimensional (2D) X-ray images. Computer software combines the 2D images into a 3D image. While it is not yet clear whether tomosynthesis will become a standard breast cancer screening tool, this new technology is under study. It has, however, been FDA approved.

Nuclear Medicine Imaging (NMI)

Scintimammography uses short-term radioactive agents that are given through an IV and absorbed into the breast’s tissues. Breast cancer cells appear to absorb more of the agents than healthy cells and these cancer cells can be imaged with a special camera.

PET scan: Cancer cells grow faster than other cells, so they use energy faster. To measure how fast glucose (the body’s fuel) is being used, a tracer (radioactive glucose) is injected into the body and the body is scanned with a positron emission tomography (PET) machine. The PET machine detects how fast the glucose is being used. If it is being used up faster in certain places, it may indicate the presence of a cancerous tumor.

Thermography

Thermography uses infrared light to measure temperature differences on the surface of the breast. Although breast cancer can cause abnormal heat patterns, many benign conditions also cause abnormal heat patterns. Thermography cannot distinguish between benign and cancerous patterns. And, because thermography measures heat at the surface of the breast, it is not good at finding cancers deeper within the breast tissue.

Neither the U.S. Food and Drug Administration (FDA) nor the American College of Radiology views thermography as a valuable breast screening or imaging tool. In June 2011, the FDA issued an alert warning the public about misleading claims by thermography practitioners and manufacturers on the screening benefits of the tool.