Overview
Mammography is a critical tool in early breast cancer detection, capable of identifying tumors as small as 1–2 mm. Modern systems utilize digital detectors that convert X-rays into electronic signals, offering superior contrast resolution compared to traditional film-based methods. The procedure involves compressing the breast to reduce tissue overlap and minimize radiation dose while maximizing image clarity. As a screening modality, mammography reduces breast cancer mortality by 20–30% among women aged 40–74. Diagnostic mammography employs additional views and magnification techniques when investigating abnormalities detected during screening or clinical exams.
Structure and Working Principle
A mammography unit consists of an X-ray generator with a molybdenum or rhodium target (28–35 kVp range), a compression device, and a digital detector system. The anode material filters characteristic X-rays optimal for breast tissue contrast (17–20 keV). Digital systems use either indirect conversion (cesium iodide scintillators with photodiodes) or direct conversion (amorphous selenium detectors). During operation, the breast is compressed to 10–15 daN force, reducing thickness to improve image quality and decrease scattered radiation. The X-ray beam passes through the breast, and the detector captures differential attenuation patterns of glandular tissue, fat, and potential lesions. Advanced units employ tomosynthesis, acquiring multiple projection images to reconstruct 3D slices and reduce tissue superposition artifacts.
Key Features
Modern mammography systems emphasize dose efficiency, with typical mean glandular doses of 1–3 mGy per view. Automatic exposure control (AEC) adjusts parameters based on breast density and thickness. High-end units feature: 1) Geometric magnification (1.5–2×) for detailed microcalcification assessment, 2) Biopsy attachments for stereotactic guidance, and 3) Dual-energy subtraction to enhance lesion visibility. Digital breast tomosynthesis (DBT) represents the current gold standard, reducing recall rates by 15–30% compared to 2D mammography. Artificial intelligence integration aids radiologists in detecting subtle asymmetries and architectural distortions, with CAD systems achieving 85–95% sensitivity for malignant masses.
Application Areas
Screening mammography is recommended annually/biennially for women over 40, with higher frequency for high-risk patients (BRCA mutations, family history). Diagnostic applications include: 1) Evaluating palpable lumps, 2) Investigating nipple discharge, 3) Pre-surgical localization of non-palpable lesions, and 4) Monitoring neoadjuvant chemotherapy response. Industrial variants inspect composite materials and electronic components, leveraging the technique's high spatial resolution (20–50 μm). Research applications include phase-contrast mammography, which enhances edge detection of low-contrast lesions through refractive properties rather than absorption alone.
Maintenance and Precautions
Quality assurance requires daily phantom imaging (e.g., ACR accreditation phantom) to verify resolution (≥4–5 lp/mm), contrast, and dose parameters. Monthly checks include compression force calibration and detector uniformity testing. Annual physicist surveys assess beam quality, half-value layer (HVL), and automatic brightness control performance. Radiation safety mandates lead shielding for operators and proper signage in controlled areas. Patient safety protocols involve minimizing repeat exposures through optimal positioning and using bismuth shields for the contralateral breast when clinically appropriate. Equipment lifespan averages 7–10 years before detector degradation or tube replacement becomes necessary.
B2B Procurement Guide
Healthcare facilities should evaluate mammography systems based on: 1) FDA/MQSA compliance, 2) Detector specifications (pixel size <85 μm, DQE >65%), 3) Workflow integration (DICOM compatibility, PACS connectivity), and 4) Upgrade paths for AI/tomosynthesis. Total cost of ownership should factor in service contracts (~$15,000–$25,000/year) and disposable components (compression paddles, grids). Leading manufacturers include Hologic (Selenia Dimensions), Siemens (MAMMOMAT Revelation), and GE Healthcare (Senographe Pristina). Consider bundled purchasing with ultrasound or MRI systems for comprehensive breast imaging departments. Emerging markets show growing demand for portable mammography units suitable for rural screening programs.