In a comparison of mammography with magnetic resonance imaging (MRI) for screening women at high risk for breast cancer, MRI was more sensitive but less specific than mammography. A comparison of mammography with magnetic resonance imaging in more than 1000 women with a genetic or familial predisposition to breast cancer. The cumulative lifetime risk of breast cancer among Dutch women is approximately 11 percent. 1 A family history of breast cancer or the presence of a germ-line mutation of the BRCA1 or BRCA2 gene increases this risk considerably and is often associated with a diagnosis at a young age. 2 , 3 Among high-risk women, the risk of breast cancer can be reduced by prophylactic mastectomy, 4 , 5 prophylactic oophorectomy, 6 , 7 or chemoprevention. 8 Early diagnosis as a result of intensive surveillance may also decrease the rate of death from breast cancer. Randomized trials have shown that mammographic screening of all women who are between . . .