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

Indications for Breast MRI

Breast MRI is definitively indicated for annual screening in women with BRCA1/2 mutations, ≥20-25% lifetime breast cancer risk, history of chest radiation before age 30, and personal history of breast cancer diagnosed before age 50 or with dense breasts. 1

High-Risk Screening Indications (Strong Recommendations)

Genetic Risk

• Women with BRCA1/2 mutations should begin annual MRI screening at age 30, continuing as long as they remain in good health 2, 1
• First-degree untested relatives of BRCA carriers qualify for the same screening protocol 2, 1
• Women with ≥20-25% lifetime breast cancer risk calculated by family history models (Claus, BRCAPRO, Tyrer-Cuzick) require annual MRI plus mammography 2, 1

Radiation-Related Risk

• Women who received chest/mantle radiation therapy before age 30 should begin annual MRI at age 25 OR 8 years after completing radiation therapy, whichever is later 2, 1
• This population demonstrates a 4% incremental cancer detection rate, comparable to genetic mutation carriers 2, 1
• By age 40-45 years, 13-20% of women treated with mantle radiation will develop breast cancer 2

Personal History of Breast Cancer

• Women with personal history of breast cancer diagnosed before age 50 should undergo annual MRI surveillance 2, 1
• Women with personal history of breast cancer AND dense breast tissue require annual MRI regardless of age at diagnosis 2, 1
• MRI sensitivity in this population is 85% versus only 23% for mammography, with cancer detection rates of 10-29 per 1,000 examinations 2, 3
• Personal history confers higher risk than family history alone in the absence of genetic mutations 2

Intermediate-Risk Screening (Consider MRI)

High-Risk Lesions

• Women with LCIS (lobular carcinoma in situ) benefit from MRI screening, with cancer detection rates similar to other high-risk populations 2, 3
• Women with atypical hyperplasia (ductal or lobular) should be considered for MRI on a case-by-case basis, particularly if additional risk factors are present (young age, family history, dense breasts) 2
• MRI provided small advantage for LCIS patients (4% cancer detection) but not for atypical hyperplasia alone 2

Dense Breast Tissue

• Dense breasts as the sole risk factor does not warrant routine MRI screening 2, 1
• However, dense breasts combined with other risk factors (personal history, LCIS, family history) strengthens the indication for MRI 2
• The Dutch Dense Tissue and Early Breast Neoplasm Screening trial is ongoing to clarify this indication 2

Diagnostic and Staging Indications

Extent of Disease Assessment

• MRI is indicated for defining extent of cancer and detecting multifocal/multicentric disease in the ipsilateral breast 1
• MRI is particularly valuable for invasive lobular carcinoma, which mammography frequently underestimates 1
• MRI can screen the contralateral breast at initial diagnosis, though this does not improve survival outcomes 1

Problem-Solving Scenarios

• MRI is recommended when conventional imaging findings are inconclusive or show large discrepancies with clinical examination 1
• MRI is useful for evaluating response to neoadjuvant chemotherapy 1
• MRI can evaluate occult primary tumors when axillary metastases are present without identified breast lesion 1

MRI Performance Characteristics

Sensitivity Data

• MRI demonstrates 71-100% sensitivity versus 16-40% for mammography in high-risk populations 2
• In BRCA carriers and women with ≥20% lifetime risk, MRI sensitivity is 90% versus 37.5% for both mammography and ultrasound 2
• MRI detected 80% of invasive cancers in Dutch screening study versus 33% for mammography 2

Specificity and False Positives

• MRI specificity ranges from 81-99%, lower than mammography's 93-99% 2
• Call-back rates range from 8-17%, with biopsy rates of 3-15% 2
• Prevalence screens have highest false-positive rates, which drop below 10% in subsequent screening rounds 2
• Positive predictive value for biopsies (PPV3) is 41% for BRCA/radiation patients and personal history patients, but only 14% for family history alone 3

Critical Technical Requirements

Imaging Protocol Standards

• MRI must be performed with dedicated breast coil by experienced breast imaging radiologists 1
• High spatial resolution imaging (approximately 1mm in-plane resolution) is essential 1
• For premenopausal women, MRI should ideally be performed during days 7-14 of menstrual cycle to minimize background parenchymal enhancement 1

Important Limitations

• Surgical decisions should NEVER be based solely on MRI findings without tissue confirmation 1
• MRI has a learning curve for radiologists, with number of investigated lesions falling with experience 2
• False-positive findings are common and require experienced interpretation 1

Populations Where MRI is NOT Routinely Recommended

• Women with average breast cancer risk do not require routine MRI screening 1
• Personal history of breast cancer diagnosed after age 65 does not require routine MRI unless lifetime risk exceeds 20% 1
• Dense breasts as the sole risk factor without additional high-risk features 2, 1
• Family history alone (without genetic mutation or calculated ≥20% lifetime risk) shows worse MRI performance with lower cancer detection rate (8 per 1,000) and PPV3 (14%) 3

Screening Frequency and Duration

• Annual MRI screening is the standard interval; no data support shorter or longer intervals 1
• MRI screening should continue annually for as long as the woman is in good health 1
• For women with BRCA mutations, alternating MRI and mammography every 6 months detected cancers not visible on mammography 6 months earlier 4