What type of MRI is ordered for breast cancer screening?

Breast MRI Ordering for Screening

For breast cancer screening, order a contrast-enhanced breast MRI (MRI breast without and with IV contrast) using a gadolinium-based contrast agent such as gadobutrol, administered at 0.1 mL/kg body weight as an intravenous bolus injection. 1, 2

Technical Specifications Required

The MRI must meet specific technical standards to be diagnostically adequate:

• High field magnet with dedicated breast coil for simultaneous bilateral imaging 1
• High spatial resolution imaging with approximately 1 mm in-plane resolution, thin slices, and high matrix 1
• Dynamic contrast-enhanced (DCE) protocol with pre-injection images and sequential post-contrast images at 1-3 minutes after injection 1
• Facility must have MRI-guided biopsy capability available, as many early cancers are detected only on MRI 1

The American College of Radiology accreditation process requires these technical parameters and intervention capabilities 1.

Contrast Administration Protocol

Gadobutrol (or equivalent gadolinium-based contrast agent) is administered as follows:

• Standard screening dose: 0.1 mL/kg (0.1 mmol/kg) body weight 2
• Administration method: Intravenous bolus by power injector, followed by normal saline flush 2
• Flow rate: Approximately 1.5-2 mL/second for screening applications 2
• Image acquisition: Commence immediately following contrast administration for screening purposes 2

Abbreviated vs. Full Protocol MRI

Both abbreviated and full protocol contrast-enhanced MRI are acceptable options:

• Full protocol MRI has been the traditional standard since 2007 guidelines 1
• Abbreviated protocol MRI demonstrates similar diagnostic accuracy with cancer detection rates of 29 per 1,000 in high-risk women, with all missed cancers being node-negative early-stage invasive malignancies 1
• Abbreviated MRI reduces examination time and cost while maintaining sensitivity 1

Non-Contrast MRI: Not Recommended

MRI breast without IV contrast is NOT appropriate for screening and has no supporting evidence. 1 The high sensitivity of breast MRI (71-100% in high-risk populations) depends entirely on the contrast enhancement patterns of malignant lesions 1. Without gadolinium contrast, the examination cannot reliably detect breast cancers.

Who Should Receive Screening Breast MRI

Annual screening breast MRI is recommended for:

• Women with BRCA1/2 mutations or untested first-degree relatives: Begin at age 25-30 1, 3
• Women with ≥20% lifetime breast cancer risk calculated by risk models: Begin at age 30 1, 3
• Women with history of chest radiation ≥10 Gy before age 30: Begin at age 25 or 8 years after radiation, whichever is later 1, 3
• Women with personal history of breast cancer diagnosed before age 50: Annual MRI surveillance 1
• Women with personal history of breast cancer and dense breast tissue: Annual MRI surveillance 1
• Women with LCIS or atypical hyperplasia on prior biopsy: Consider MRI, especially with other risk factors 1

Performance Characteristics

MRI demonstrates superior sensitivity compared to mammography in high-risk populations:

• MRI sensitivity: 71-100% across multiple studies 1
• Mammography sensitivity: 16-40% in the same populations 1
• MRI specificity: 81-99% 1
• Cancer detection rate: 8-29 per 1,000 examinations in elevated-risk women 1
• Interval cancer rate: Below 10% when MRI is included 1

MRI detects smaller, node-negative invasive cancers at earlier stages (43-50% ≤1 cm diameter) compared to mammography alone 1.

Important Caveats

Higher recall and biopsy rates occur with MRI:

• Recall rate: 15.1% for MRI vs 6.4% for mammography 1
• Biopsy rate: 11.8% for MRI vs 2.4% for mammography 1
• Positive predictive value for biopsy (PPV3): Ranges from 36-48% depending on population and radiologist experience 1

There is a learning curve for radiologists interpreting breast MRI - community practice groups initially report callback rates exceeding 50%, which decrease with experience 1. High-volume centers demonstrate better specificity and positive biopsy rates 1.

Contraindications to gadolinium-based contrast agents:

• Severe renal impairment (GFR <30 mL/min/1.73m²) or acute kidney injury increases risk of nephrogenic systemic fibrosis 2
• Screen patients for renal dysfunction before contrast administration, especially those >60 years, with hypertension or diabetes 2

What NOT to Order

Do not order MRI breast without IV contrast - it has no evidence supporting its use for screening 1. Do not order molecular breast imaging (MBI) for screening surveillance in any high-risk population - it is not recommended 1. Do not add ultrasound to annual mammography plus MRI in high-risk women, as it does not identify additional cancers 1.