Mammography is a specific type of imaging that uses a low-dose x-ray system to examine breasts. A mammography exam, called a mammogram, is used to aid in the diagnosis of breast diseases in women.
An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.
Mammography plays a central part in early detection of breast cancers because it can show changes in the breast up to two years before a patient or physician can feel them. Current guidelines from the U.S. Department of Health and Human Services (HHS), the American Cancer Society (ACS), the American Medical Association (AMA) and the American College of Radiology (ACR) recommend screening mammography every year for women, beginning at age 40. Research has shown that annual mammograms lead to early detection of breast cancers, when they are most curable and breast-conservation therapies are available.
The National Cancer Institute (NCI) adds that women who have had breast cancer and those who are at increased risk due to a genetic history of breast cancer should seek expert medical advice about whether they should begin screening before age 40 and about the frequency of screening.
Diagnostic mammography is used to evaluate a patient with abnormal clinical findings—such as a breast lump or lumps—that have been found by the woman or her doctor. Diagnostic mammography may also be done after an abnormal screening mammography in order to determine the cause of the area of concern on the screening exam.
Full-Field Digital Mammography with CAD
With digital mammography, low energy x-rays pass through the breast exactly like conventional mammograms but are captured and digitized by an electronic digital detector instead of film. This electronic image can be displayed on a video monitor like a TV or printed onto film. This is similar to digital cameras that produce pictures that can be displayed on a computer screen or printed on paper. The radiologist can manipulate the mammogram electronically to magnify an area, change the contrast, or alter the brightness.
Digital mammography improves contrast and signal to noise ratios. These may allow better cancer detection. Near instantaneous image acquisition and the ability to transmit images electronically around the world are also significant advantages. However, the most important scientific application is the potential to use advanced computer and electronic technologies to manipulate the image in order to better “see” certain breast tumors that are currently difficult to visualize on film screen mammography systems.
A Computer-Aided-Diagnosis (CAD) system is designed to improve the process of mammography screening by detecting very subtle changes in breast tissue that even the most trained eye might not recognize. The computer aids the radiologist who reads the mammogram; and provides a valuable second read that increases the chances of detecting breast cancer in its earliest stages.