ARRT Mammography cheat sheet

MQSA requires a written results summary in lay language to every patient within 30 days; when findings suggest malignancy, the facility must attempt direct contact promptly.

BI-RADS: 0 = incomplete, needs additional imaging; 1 = negative; 2 = benign; 3 = probably benign (<2% risk, 6-month follow-up); 4 = suspicious (2–95%, biopsy); 5 = highly suggestive (≥95%); 6 = known malignancy.

Screening guidance differs: ACR and ACS recommend annual mammography beginning at age 40 for average-risk women; USPSTF recommends biennial screening for ages 50–74.

Average lifetime breast cancer risk in US women is about 13% (1 in 8); five-year risk models include the Gail (BCRAT) and Tyrer-Cuzick tools.

High-risk indicators prompting earlier or supplemental screening: BRCA1/2 or other pathogenic mutation, chest radiation before age 30, lifetime risk ≥20%, or heterogeneously/densely dense tissue on prior imaging.

History elements to document: personal and family history of breast cancer, prior biopsies and surgeries, implants or reduction, hormone therapy, pregnancy/lactation status, current symptoms, and date of last mammogram.

Compression discomfort peaks during the exposure and resolves when the paddle is released; adequate compression lowers absorbed dose and improves contrast and spatial resolution.

Vasovagal signs (pallor, diaphoresis, dizziness) require stopping the examination, supporting the patient to a safe position, elevating the legs, and resuming only after recovery.

Each breast has 15–20 lobes; each lobe drains through a lactiferous duct to the nipple, and Cooper suspensory ligaments span from the deep fascia to the skin.

Blood supply: internal mammary (thoracic) perforating branches supply roughly 60%, with contributions from lateral thoracic and thoracoacromial arteries; venous drainage parallels to internal mammary and axillary veins.

Lymphatic drainage: about 75% flows to axillary nodes; the remainder drains to internal mammary (parasternal) nodes and, less commonly, posterior intercostal nodes.

The upper outer quadrant holds the greatest glandular volume and is the site of roughly half of all breast cancers; the tail of Spence extends this tissue into the axilla.

Benign calcifications: milk of calcium (teacup-shaped on a true 90-degree lateral), skin, vascular tram-track, secretory, and dystrophic; suspicious: pleomorphic and fine linear branching.

Mass descriptors: shape (oval, round, irregular), margin (circumscribed, obscured, microlobulated, indistinct, spiculated), and density (high, equal, low, fat-containing).

Common benign entities: fibroadenoma (oval, circumscribed, young women), simple cyst, hamartoma (mixed fat and glandular), and intramammary lymph node with a fatty hilum.

Malignant patterns: spiculated mass, architectural distortion without a central mass, fine linear branching calcifications, and inflammatory carcinoma with diffuse skin thickening and peau d'orange.

Mean glandular dose limit is 3 mGy (0.3 rad) per view for a standard 4.2 cm compressed breast of 50% glandular composition.

Target/filter pairs with typical kVp: Mo/Mo 25–28, Mo/Rh 26–31, Rh/Rh 26–31, W/Rh 26–32, W/Ag 26–34; higher-Z filters and higher kVp are used for dense or large breasts.

Focal spot: 0.3 mm nominal for contact imaging and 0.1 mm for magnification; magnification factors near 1.5× to 2× raise dose and require the small focal spot.

Beam quality is verified by half-value layer, the aluminum thickness that halves exposure; minimum HVL is about 0.30 mm Al for a molybdenum target and filter at 26 kVp.

Tolerances: kVp accurate within ±5%, compression force accurate within ±10% (about 44 N) of indicated, and AEC reproducibility with a mAs coefficient of variation of 0.05 or less.

Compression system: must be capable of at least 111 N, with clinical forces of roughly 111–200 N, power-driven movement, a maximum-force limit, and a manual release.

Grid: moving grid of about 5:1 ratio with 30–40 lines/cm whose lines are blurred by motion during exposure; magnification views are often performed without a grid.

Digital detectors: CsI scintillator with amorphous silicon array (indirect) or amorphous selenium photoconductor (direct); detector elements are typically 50–100 µm, with phantom, flat-field, and artifact QC.

Standard screening series is a craniocaudal and a mediolateral oblique view of each breast; the MLO is the single most useful view because it images the greatest amount of tissue, including the axillary tail.

MLO positioning: tube/receptor angle typically 45 degrees (range 45–60), lower receptor edge at the inframammary fold, pectoralis muscle extending to the nipple line, nipple in profile, no sagging.

CC positioning: breast lifted and pulled forward, patient's head turned away, nipple in profile, medial tissue to the cleavage line, lateral tissue included, retromammary fat visible.

Additional views: true lateral (90 degrees), exaggerated CC lateral (XCCL), cleavage view, rolled medial/lateral views, tangential views, spot compression, and implant-displaced views.

Eklund technique: displace the implant posteriorly against the chest wall while pulling native breast tissue forward over it; standard and implant-displaced views are both performed.

Required labeling on every image: patient name or identification, date, laterality, view designation, facility name, technologist identification, and machine or detector identification.

Artifacts to recognize: motion blur, grid lines, underexposure noise, skin folds, hair, antiperspirant density, and detector or plate dust and scratches.

Adequacy and symmetry: right and left images are compared for positioning, compression, and exposure; repeat is indicated when the nipple is not in profile or essential tissue is excluded.