Improving mammograms

Although a mammogram is an excellent way to find most breast cancers when they are small and most curable, it does not detect all breast cancers. Newer techniques are being looked at to try to make mammograms more accurate.

Computer-aided detection and diagnosis

Computer-aided detection and diagnosis (CAD) was developed to help radiologists find suspicious changes on mammograms. This can be done with standard film mammograms or with digital mammograms.

Computers can help doctors find abnormal areas on a mammogram by acting as a second set of eyes. For standard mammograms, the film is fed into a machine which converts the image into a digital signal that is then analyzed by the computer. The technology can also be applied to an image captured with a digital mammogram. The computer then displays the picture on a video screen, with markers pointing to areas the radiologist should check more closely.

Early research on CAD showed a clear improvement in finding small cancers, with only a small increase in the number of women who had to come back for more tests. But studies of CAD in community practice have shown mixed results. Some showed a clear benefit from the use of CAD, and others showed that it did not find more cancers or find cancers earlier, but did increase the number of women who needed to come back for more tests and/or to have breast biopsies. Current research suggests that CAD is not a substitute for experience and expertise in reading mammograms. In other words, CAD is only helpful when the radiologists are experienced and have expertise in reading mammograms. Whether CAD will continue to be used in the future is not clear.

Tomosynthesis (3D mammography)

This technology is basically an extension of a digital mammogram. For this test, the breast is compressed once and a machine takes many low-dose x-rays as it moves over the breast. The images can then be combined into a 3-dimensional picture. Although this uses more radiation than most standard 2 view mammograms, it may allow doctors to see problem areas more clearly, lowering the chance that the patient will need to be called back for more tests.

A breast tomosynthesis machine was approved by the Food and Drug Administration (FDA) in 2011 for use in the United States, but the role of this technology in screening and diagnosis is still not clear.