The American College of Radiology (ACR ) recommends all women, but especially Black women and women of Ashkenazi Jewish descent, undergo risk assessment and possible genetic testing by age 30 to identify those at higher risk who can then be counseled to begin earlier and more aggressive screening for breast cancer. All women benefit most from starting screening at least by age 40. In a recent analysis  from Harvard, Black, Hispanic, and Asian women have peak incidence of breast cancer in their 40s: it is especially important to start screening at least by age 40 in these groups.
The ACR, National Comprehensive Cancer Network (NCCN) , and American Society of Breast Surgeons, recommend annual MRI in the following subgroups of women:
- Women with known disease-causing BRCA1/2 mutation(s), other disease-causing mutation(s), or their untested first-degree relatives, should begin annual screening MRI only between age 25-29, adding annual digital mammography/tomosynthesis at age 30 and beyond.
Note: There is emerging evidence that the benefit of mammography is relatively small in BRCA1 carriers prior to the age of 40; therefore, the ACR suggests BRCA1 mutation carriers may consider delaying mammography until age 40 only if they receive contrast-enhanced MRI annually starting at age 25. Annual mammography is of benefit in those with BRCA2 or other disease-causing mutations.
- Women with prior chest/mantle radiation therapy (cumulative dose of ≥ 10 Gy) before age 30 should begin MRI and annual mammography at age 25 or at least 8 years after completion of radiation, whichever is latest.
- Women with a calculated lifetime risk of breast cancer of ≥ 20%. Only models that include detailed family history such as Tyrer-Cuzick (which now includes breast density as a risk factor), BRCAPRO, BOADICEA, Claus, or Penn II, but not the Gail model, should be used to calculate risk for the purposes of MRI screening.
- Women with a personal history of breast cancer and dense breasts or diagnosis by age 50 regardless of breast density. A personal history of breast cancer is not included in risk models, but all women diagnosed with breast cancer at or before age 50 and treated with breast-conserving therapy have a ≥ 20% lifetime risk for a new breast cancer.
- Annual MRI may be considered in addition to annual mammography (with or without tomosynthesis) in women with a personal history of breast cancer diagnosed after age 50 and without dense breasts, and/or a history of lobular carcinoma in situ (LCIS) or prior atypia [e.g. atypical ductal hyperplasia (ADH), or atypical lobular hyperplasia (ALH), or atypical papilloma].
In women who meet guidelines for MRI screening but are unable to tolerate it and who have dense breasts, the ACR suggests ultrasound be considered in addition to annual mammography. If MRI is performed, there is no benefit to screening ultrasound.
Where available, contrast-enhanced mammography may be a reasonable alternative to MRI for high-risk women, though further validation is warranted [4-6].