Mammography is essentially a low-dose x-ray used to examine breasts. A mammogram is helpful in the diagnosis of breast cancer, and other breast disease in women. Although the procedure may cause some temporary pain for some women (from compressing the breast), it is not invasive and the benefits far outweigh any potential discomfort.

An x-ray is another type of imaging used by healthcare providers to help diagnose breast cancer. This test exposes a part of the body, the breast, to a small amount of ionizing radiation to produce a picture. According to Radiology Info, a newsletter of the American College of Radiology, x-rays are "the oldest and most frequently used form of medical imaging." However, we have moved beyond the simple x-ray in recent years. Two new tests to help diagnose breast cancer are digital mammography and computer-aided detection.

Digital mammography, also called full-field digital mammography (FFDM), is essentially a mammogram without the traditional x-ray film. Detectors similar to those found in digital cameras have replaced the film. These detectors convert the x-ray signals into electrical signals, and then feed them to the computer where they are viewed on a monitor or printed just like a conventional mammogram. The process is no different from the usual mammogram for the patient. The only difference is the way the results are collected and viewed.

Computer-aided detection (CAD) systems utilize special software to search an image (obtained using film or digital mammography) for abnormalities in density or mass, and may offer better views of any calcification. The CAD system highlights these and alerts the radiologist to areas that may need further study, since all may be indicative of cancer.

Which is better?

Preliminary studies show digital mammography may be better at detecting breast cancer than film mammography for women who fall into the following categories.

• Over 50 years old
• No history of dense or very dense breasts
• No longer menstruating

The potential advantages of digital mammography are many. Since the image is captured in less than one minute, more women may be encouraged to schedule a mammography. If breast cancer is found, new digital systems can create a snapshot of the area. This may speed up the biopsy process by ensuring accuracy of needle placement in order to reduce discomfort for the patient. Add to this the ease of more accurately copying and transmitting mammography results, lower doses of radiation, the discovery of more cancers with more accurate staging, and you have a recipe for success.

Keep in mind that digital mammography, like any other test, does have some limitations. Resolution issues may need to be corrected so that subtle changes may be more clearly detected, and work stations need to be more user-friendly. Also, conventional film mammography is still a better way to detect microcalcifications which may be a clue to early cancer. However, with, quality issues are bound to be addressed as the equipment is improved in response to user feedback.

According to the American College of Radiology, the process of converting to digital mammography will be formidable, since the cost of the necessary equipment is three or four times more expensive than conventional equipment. Reimbursement rates for film mammography are among the lowest for any imaging procedure. As a result, payments are not likely to cover the necessary costs of conversion.

Digital mammography may be an excellent option in the future. Although there are already over 10,000 screening sites across the country, until it becomes a more cost-effective screening option conventional film mammography remains the best and most readily available tool for the detection of breast cancer.

References and Other Resources:

Radiology Info: "Full-Field Digital Mammography: A Potential Alternative to the Traditional Film-Screen Technique?"

American Cancer Society: Mammograms and Other Breast Imaging Procedures, "What is a Mammogram?" American Cancer Society