A screening mammogram is an X-ray of the breast used to detect breast changes in women who have no signs of breast cancer. It usually involves two X-rays of each breast. Using a mammogram, it is possible to detect a tumor that cannot be felt.
A diagnostic mammogram is an X-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape.
A diagnostic mammogram is also used to evaluate abnormalities detected on a screening mammogram. It is a basic medical tool and is appropriate in the work-up of breast changes, regardless of a woman's age.
Mammography has been used for about 30 years, and in the past 15 years technical advancements have greatly improved both the technique and results. Today, specialized equipment, used only for breast X-rays, produce studies that are high in quality but low in radiation dose.
Mammography may be used either for screening or to make a diagnosis. Women older than 25 years should undergo diagnostic mammography if they have symptoms such as a palpable lump, breast skin thickening or indentation, nipple discharge or retraction, erosive sore of the nipple, or breast pain.
A mammogram may be used to evaluate breast pain when physical examination and history are not conclusive. Women with breasts that are dense, "lumpy," and/or very large may be screened with mammography, as physical examination may be difficult to perform.
Women who are at high risk for breast cancer or with a history of breast cancer may be routinely screened with mammography.