Mammography (Screening)

Screening mammography is a low-dose X-ray examination of the asymptomatic breast performed to detect early, clinically occult breast cancer and reduce breast cancer mortality. Standard two-view digital mammography (with digital breast tomosynthesis increasingly used) is the internationally validated screening tool, and findings are communicated using the standardised BI-RADS lexicon. Effective screening depends on high-quality technique, comparison with prior studies and structured interpretation.

Indications

Routine breast cancer screening in average-risk women, typically from age 40-50 depending on the national programme
Annual or biennial screening intervals per programme guidelines
Earlier and/or supplemental screening (often with MRI) in high-risk women (BRCA carriers, strong family history, prior chest radiotherapy)
Baseline imaging before hormone therapy or as part of surveillance
Continued screening in women with prior breast cancer (surveillance rather than diagnostic when asymptomatic)

Contraindications & Cautions

Screening mammography is for asymptomatic women; a symptomatic patient (palpable lump, nipple discharge, skin change) requires diagnostic work-up, not screening
Pregnancy and lactation are relative contraindications for screening (defer or use targeted diagnostic imaging with justification)
Very low radiation dose (mean glandular dose ~0.4 mSv for a two-view study); benefit outweighs risk in the screening age group
Recent breast surgery/biopsy may warrant deferral until healing
Apply ALARA; balance benefits and harms (false positives, overdiagnosis) when counselling

Patient Preparation

Schedule (in premenopausal women) during the first half of the cycle when breasts are less tender
Advise no deodorant, talc or lotion on the breasts/axillae, as these can mimic calcifications
Take a history of prior surgery, biopsies, implants, symptoms, hormone use and family history
Obtain and load prior mammograms for comparison
Explain the compression and its purpose (reduces dose, spreads tissue, reduces motion)
Position the patient and mark any scars, moles or palpable areas

Technique & Parameters

Standard two views per breast: craniocaudal (CC) and mediolateral oblique (MLO)
Full-field digital mammography; digital breast tomosynthesis (3D) increasingly added to improve cancer detection and reduce recall in dense breasts
Low kVp (~26-32 kVp) with molybdenum/rhodium or tungsten targets and appropriate filtration; automatic exposure control
Firm compression to reduce thickness, spread tissue, lower dose and reduce motion blur
MLO should include the pectoral muscle to the level of the nipple and the inframammary fold; CC should include posterior/medial tissue
Additional diagnostic views (spot compression, magnification, true lateral) are performed at recall, not at screening
Adhere to quality-control standards for exposure, positioning and image quality

Systematic Review

Confirm identity, laterality, adequate positioning and image quality (PGMI criteria)
Compare CC and MLO of each breast and compare with prior studies for change
Assess overall breast density (BI-RADS a-d categories)
Search systematically for masses: shape, margin, density
Search for calcifications: morphology and distribution
Assess for architectural distortion and asymmetries (focal, global, developing)
Evaluate the retroglandular/retroareolar regions, axillary tail and lymph nodes
Check skin, nipple and trabecular pattern for thickening or retraction

Key Findings & Significance

A spiculated or irregular mass with ill-defined margins is highly suspicious for malignancy
Fine pleomorphic or fine linear/branching calcifications in a linear or segmental distribution suggest DCIS or invasive cancer
Architectural distortion without a central mass is suspicious for malignancy (or radial scar)
A developing or enlarging focal asymmetry compared with priors warrants recall
Round/oval circumscribed masses are usually benign (cyst, fibroadenoma) but may need ultrasound correlation
Coarse 'popcorn' calcifications suggest an involuting fibroadenoma; rim/eggshell calcifications suggest cysts or fat necrosis
Skin or nipple retraction and skin thickening may indicate underlying malignancy or inflammatory change
Dense breast tissue reduces sensitivity and may warrant supplemental imaging

Differential Considerations

Spiculated mass: invasive carcinoma, radial scar/complex sclerosing lesion, post-surgical scar, fat necrosis
Circumscribed mass: cyst, fibroadenoma, phyllodes tumour, papilloma, circumscribed carcinoma (e.g. mucinous, medullary)
Pleomorphic/segmental calcifications: DCIS, invasive carcinoma
Benign calcifications: vascular, secretory (plasma cell mastitis), milk of calcium, skin, fibroadenoma, fat necrosis
Architectural distortion: carcinoma, radial scar, post-surgical change, sclerosing adenosis
Asymmetry: normal overlapping tissue, developing asymmetry from carcinoma, hormonal change
Axillary lymphadenopathy: benign reactive, metastatic disease, lymphoma, systemic causes

Pearls & Pitfalls

Always compare with prior mammograms - a stable finding over years is reassuring, while any interval change lowers the threshold for recall
Cancers are commonly missed in dense tissue, at the film edges, in the retroglandular/axillary tail and behind the nipple - review these areas deliberately
Correlate any palpable lump with imaging; a normal mammogram does not exclude cancer in a symptomatic patient - proceed to diagnostic work-up and ultrasound
Deodorant and skin lesions can simulate suspicious calcifications; note skin markers and confirm on true lateral
Architectural distortion is subtle and one of the most frequently overlooked signs of malignancy
Tomosynthesis reduces the masking effect of overlapping tissue and lowers recall rates
Assess both views together; a real lesion should be identifiable on orthogonal projections

Structured Report

State the examination type (2D/tomosynthesis), views, laterality and comparison
Report breast density category (BI-RADS a-d)
Describe any mass, calcifications, asymmetry or distortion using the BI-RADS lexicon with location and size
Assign a final BI-RADS assessment category (0 incomplete, 1-2 negative/benign, 3 probably benign, 4-5 suspicious/highly suspicious, 6 known malignancy)
Give a clear management recommendation matched to the category (routine screening, short-interval follow-up, recall for diagnostic work-up, or biopsy)
Include audit-relevant data and communicate significant findings appropriately

References

ACR BI-RADS Atlas (Breast Imaging Reporting and Data System), 5th Edition
ACR Practice Parameter for the Performance of Screening and Diagnostic Mammography
NHS Breast Screening Programme Guidance / European Guidelines for Quality Assurance in Breast Cancer Screening
US Preventive Services Task Force (USPSTF) Breast Cancer Screening Recommendations
Kopans DB. Breast Imaging, Wolters Kluwer

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

Mammography (Screening)

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References