Over the past century, mammography, or X-ray imaging of the breast, has become an accepted, although controversial, tool in the diagnosis of breast cancer. Breast cancer remains one of the deadliest diseases that strikes women; an estimated one out of every nine women will develop the disease in her lifetime. Mammography is considered an important screening and diagnostic tool because it can detect tumors while still small and most easily treated. In one study, women whose breast cancers were found early through mammograms had a five-year survival rate of 82 percent, while a group of women whose cancers were not found by mammograms had a five-year survival rate of just 60 percent. The American Cancer Institute guidelines recommend women aged 40 to 49 be screened every one to two years, and that women aged 50 and older be screened annually because the incidence of breast cancer increases with age.

Researchers began experimenting with...