What are the indications for MRI (Magnetic Resonance Imaging) of the breast?

Indications for Breast MRI

Breast MRI is primarily indicated for annual screening in women with ≥20% lifetime breast cancer risk, including those with BRCA1/2 mutations, strong family history, or prior chest radiation before age 30, and should begin at age 30 (or 8 years post-radiation, whichever is later). 1

High-Risk Screening Indications (Strongest Evidence)

Genetic and Familial Risk

• Annual MRI screening is recommended for women with BRCA1/2 mutations or other high-risk genetic variants, starting at age 30 1
• Women with ≥20-25% lifetime breast cancer risk based on family history models should undergo annual MRI plus mammography 1
• First-degree untested relatives of BRCA carriers qualify for MRI screening 1

Radiation-Induced Risk

• Women who received chest/mantle radiation therapy before age 30 (cumulative dose ≥10 Gy) should begin annual MRI at age 25 or 8 years after completing radiation, whichever is later 1
• The incremental cancer detection rate in this population is approximately 4%, similar to genetic mutation carriers 1

Personal History of Breast Cancer

• Annual MRI surveillance is recommended for women with personal history of breast cancer diagnosed before age 50 1
• MRI is particularly beneficial for those with personal history AND dense breast tissue 1
• Cancer detection rates with MRI in this population range from 10-29 per 1,000 screened 1
• MRI sensitivity reaches 85% versus only 23% for mammography alone in women with prior breast cancer 1

High-Risk Lesions

• MRI should be considered for women with LCIS (lobular carcinoma in situ), especially when combined with other risk factors 1
• The Adjunct Screening trial demonstrated 48% positive predictive value for MRI in LCIS patients 1
• For atypical hyperplasia alone, evidence is insufficient, though MRI may be considered on a case-by-case basis with additional risk factors 1

Diagnostic and Staging Indications

Extent of Disease Assessment

• MRI is useful for defining extent of cancer and detecting multifocal/multicentric disease in the ipsilateral breast 1
• Particularly valuable in lobular cancers, which are often underestimated by mammography [1, @19@]
• Can screen the contralateral breast at initial diagnosis (though this doesn't improve survival outcomes) 1

Special Clinical Scenarios

• MRI is recommended when conventional imaging findings are inconclusive or show large discrepancies with clinical examination 1
• Essential for identifying occult primary tumors in women presenting with axillary adenocarcinoma or Paget's disease when mammography/ultrasound are negative 1
• Useful before and after neoadjuvant chemotherapy to assess extent of disease and treatment response 1
• Recommended for evaluating breasts with implants when malignancy is suspected 1

Dense Breast Tissue

• MRI may be useful in women with extremely dense breasts, though evidence for density alone as an indication remains limited 1
• The Dutch Dense Tissue trial is ongoing to provide definitive data 1
• When dense breasts are combined with other risk factors (LCIS, personal history), MRI benefit is established 1

Important Caveats and Limitations

False-Positive Considerations

• False-positive findings on breast MRI are common; surgical decisions should NEVER be based solely on MRI findings without tissue confirmation 1
• Additional tissue sampling of MRI-detected abnormalities is mandatory 1
• Specificity improves with successive screening rounds as radiologists gain experience 2

Technical Requirements

• MRI must be performed with dedicated breast coil by experienced breast imaging radiologists 1
• The facility MUST have capability for MRI-guided biopsy and wire localization 1
• High spatial resolution imaging (approximately 1mm in-plane resolution) is essential 1

Populations Where MRI is NOT Routinely Recommended

• Women with average breast cancer risk 1
• Personal history of breast cancer diagnosed after age 65 (unless lifetime risk exceeds 20%) 1
• Dense breasts as the sole risk factor without additional high-risk features 1
• Follow-up surveillance after breast cancer treatment unless lifetime risk of second primary exceeds 20% 1

Timing Considerations

• MRI screening should continue annually for as long as the woman is in good health 1
• No data support screening intervals shorter or longer than annual 1
• For premenopausal women, MRI is ideally performed during days 7-14 of the menstrual cycle to minimize background parenchymal enhancement 1