Medical imaging is a critical tool in the fight against breast cancer. It’s used to detect and stage breast cancer, guide treatments, determine if a treatment is working and monitor recurrence.

Screening uses imaging to detect abnormalities in the breast when no signs or symptoms are present. Diagnostic imaging is used to evaluate an abnormality in the breast discovered clinically, on a screening mammogram, or when a breast lump or other change is noticed.

Mammography uses X-ray images to create detailed pictures of the inside of the breast. It can find cancers at an early stage when they are too small to be felt and chances for survival are highest.

Most mammography centers use digital breast tomosynthesis (also called “tomo” or three-dimensional (3D) mammography). Imaging machines take multiple, 2-dimensional digital mammograms. Computer software combines the 2-dimensional X-ray images into a 3-dimensional or 3D image.

Either digital breast tomosynthesis or 2D digital mammography are appropriate for breast cancer screening. Some studies have shown that 3D mammography may find a few more breast cancers than 2D mammography, but the exact benefit is still under study.

Breast MRI, in addition to mammography, is recommended for breast cancer screening in certain women at higher risk.

Breast ultrasound uses high frequency sound waves to create images inside the breast. It is often used to determine whether a mass is a solid tumor or a cyst, but it can’t determine whether a mass is cancerous or not. It’s not used for breast cancer screening, but may be used in follow-up on an abnormal finding.

Other imaging technologies are under study for breast imaging.