Variety of Imaging Tools Used for Breast Cancer Screening and Diagnosis

By Audrey Garrett, MD, MPH

At Women’s Care, we probably sound like a broken record. If so, it’s only because the message is so vitally important: When it comes to breast cancer—the third leading cause of death in women—early detection is key. You can help ensure early detection of breast cancer by doing three things faithfully: Monthly breast self-exams, annual mammograms after age 40 and annual physician exams.

Fortunately for women today, mammograms and other imaging technology are available to help physicians detect, diagnose and pinpoint breast cancers. Here are a few of the imaging tools available:


Mammograms are technology’s primary tool for early detection of breast cancer. They are X-ray photographs of the breast taken when breast tissue is compressed between two plates. Radiologists evaluate the X-ray for abnormalities. Abnormalities on the mammogram such as calcifications, tissue distortions or abnormal densities may be suspicious for cancer and may warrant further testing.

When used to detect and evaluate breast abnormalities in women who have no breast symptoms, the procedure is known as a screening mammogram. The goal of the screening mammogram is to find cancer when it is still too small to be felt. Finding small breast cancers early by a screening mammogram greatly improves a woman’s chance for successful treatment.

Diagnostic mammograms are those done on women with problems such as a lump, pain or nipple discharge, or on women who have had an abnormality found during a screening mammogram. During a diagnostic mammogram, more images are taken—some of them with magnification—to make a small area of suspicious breast tissue easier to evaluate.


Ultrasound of the breast is sometimes used to evaluate breast problems that are found during a screening or diagnostic mammogram, or during a physical exam. Because ultrasound can distinguish between liquid and solid, it’s useful in differentiating fluid-filled (cystic) lesions from solid lesions. Breast ultrasound may also be used to help doctors guide a biopsy needle into some breast lesions.

Ultrasound isn’t routinely used for screening. However, it has become a valuable tool to use along with mammograms, since it is widely available, noninvasive and less expensive than other options.

Magnetic Resonance Imaging (MRI)

A supplemental tool to mammography, MRI is usually performed when a mammogram or ultrasound of the breast is abnormal but the nature of the abnormality can’t be determined. MRI can also be useful in screening a breast with an implant, or for screening younger women who have a genetic mutation that puts them at significant risk of developing cancer. Mammograms may not be useful in some of these patients because of greater density of breast tissue in younger women. This use is experimental and is currently being studied. The only screening tool currently approved by the FDA is mammography.

Newer and Experimental Breast Imaging Methods

Researchers are continuing to explore other methods of breast imaging to find cancers even smaller than those detected by mammograms and to improve the ability to differentiate benign breast conditions from cancers. These methods—including nuclear medicine studies, electrical impedance imaging, thermography and other experimental imaging tests—need further study before their usefulness can be conclusively determined.