MRI Breast (Screening/Diagnostic)

Dynamic contrast-enhanced breast MRI is the most sensitive imaging test for invasive breast cancer and is used for high-risk screening, disease extent assessment, and problem-solving. It relies on tumor neoangiogenesis producing early enhancement and characteristic kinetics, interpreted alongside morphology using the BI-RADS lexicon. It also evaluates silicone implant integrity without contrast. Careful attention to background parenchymal enhancement and timing is essential for accurate interpretation.

Indications

Annual high-risk screening (BRCA/other mutation carriers, prior chest radiation, strong family history, lifetime risk >=20%)
Assessment of extent of disease and multifocal/multicentric/contralateral disease in newly diagnosed cancer
Problem-solving of equivocal mammographic/ultrasound or clinical findings
Evaluation of response to neoadjuvant chemotherapy
Assessment of the primary in occult breast cancer presenting with axillary metastasis
Silicone implant integrity evaluation (non-contrast protocol)
Evaluation in dense breasts where mammographic sensitivity is reduced

Contraindications & Cautions

Non-MRI-conditional implanted devices and ferromagnetic foreign bodies
Severe renal impairment (eGFR <30) limits gadolinium; nephrogenic systemic fibrosis risk
Gadolinium hypersensitivity
Pregnancy: avoid gadolinium; breast MRI generally deferred
Timing in premenopausal women: schedule days 7-14 of the menstrual cycle to reduce background enhancement
Inability to lie prone and still for the examination

Patient Preparation

MRI safety screening for devices and implants
Schedule during the second week of the menstrual cycle in premenopausal women
Review the value of pausing hormone replacement therapy per local protocol
Check eGFR and obtain contrast consent
Establish reliable antecubital IV access for power-injected gadolinium
Position prone with both breasts pendant in a dedicated bilateral breast coil
Ensure comfortable, symmetric positioning to minimize motion and enable subtraction

Technique & Parameters

1.5T or 3T (3T preferred) with a dedicated bilateral breast coil, prone positioning
Bilateral axial T2/STIR for cysts, edema, and lymph node characterization
Axial T1 fat-suppressed pre-contrast, then multiple dynamic post-contrast acquisitions (early ~90 s and delayed phases)
Subtraction images and maximum intensity projections for lesion detection
High spatial resolution with <=1 mm in-plane and thin slices for morphology
Diffusion-weighted imaging as an adjunct to improve specificity
For implants: T2 with silicone-selective and water-suppressed sequences, no contrast required

Systematic Review

Assess and grade background parenchymal enhancement (minimal, mild, moderate, marked)
Review MIPs and subtractions for foci, masses, and non-mass enhancement
Characterize each enhancing lesion by morphology (shape, margin, internal enhancement)
Analyze kinetic curves (initial upstroke and delayed washout/plateau/persistent)
Compare with mammography/ultrasound and prior MRI for stability
Evaluate the axillary, internal mammary, and supraclavicular nodes
For implants, assess for intra/extracapsular rupture signs
Inspect skin, nipple, chest wall, and imaged lung/mediastinum

Key Findings & Significance

Irregular mass with spiculated/irregular margins and rim enhancement with washout kinetics suggests malignancy
Segmental or linear clumped non-mass enhancement suggests DCIS or invasive disease
Persistent enhancement with smooth oval morphology favors a benign lesion (e.g., fibroadenoma with nonenhancing septa)
Washout kinetic curve (type 3) increases suspicion; persistent (type 1) is more often benign
Linguine sign indicates intracapsular implant rupture; free silicone indicates extracapsular rupture
Marked background parenchymal enhancement can mask lesions and reduce specificity
Enlarged, rounded, cortically thickened axillary node suggests nodal metastasis

Differential Considerations

Enhancing mass: invasive carcinoma, fibroadenoma, papilloma, phyllodes, lymph node
Non-mass enhancement: DCIS, invasive lobular carcinoma, fibrocystic change, hormonal/background enhancement
Rim-enhancing lesion: invasive carcinoma, fat necrosis, abscess, inflamed cyst
Washout kinetics: malignancy, but also some fibroadenomas and papillomas
Implant abnormality: intracapsular rupture, extracapsular rupture, radial folds (mimic), silicone granuloma
Multiple enhancing foci: benign hormonal enhancement vs multifocal malignancy

Pearls & Pitfalls

Morphology outweighs kinetics; assess both but do not dismiss a suspicious mass with benign curves
Marked background enhancement reduces sensitivity/specificity; time to cycle phase when possible
Subtraction misregistration from motion can create false enhancement; verify on source images
Fat necrosis and post-surgical change commonly mimic malignancy; correlate with history and T1 fat signal
Nonenhancing internal septa in an oval mass are characteristic of fibroadenoma
Do not overlook the axilla and internal mammary chain
MRI-detected lesions without a correlate may require MRI-guided biopsy

Structured Report

State indication, technique, cycle timing, contrast, and comparison studies
Report background parenchymal enhancement and fibroglandular density
Describe each lesion using BI-RADS lexicon (morphology, internal enhancement, kinetics, size, location)
Assign a BI-RADS final assessment category and management recommendation
Report nodal, skin, nipple, and chest wall involvement
For implants, state integrity and rupture type if present
Impression: most significant finding, correlation needs, and biopsy/follow-up recommendation

References

ACR BI-RADS Atlas (MRI) lexicon and assessment categories
ACR Practice Parameter for the Performance of Contrast-Enhanced Breast MRI
ACS/ACR high-risk breast MRI screening guidelines
EUSOBI recommendations for breast MRI
RadioGraphics reviews on breast MRI interpretation, kinetics, and implant evaluation

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

MRI Breast (Screening/Diagnostic)

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References