Mammography Techniques

Mammography Basics - X-ray Vision Unveiled

• Principle: Low-dose X-rays for breast imaging.
• X-ray Tube:
  • Low kVp (25-35 kVp) for high soft tissue contrast.
  • Targets: Molybdenum (Mo), Rhodium (Rh), Tungsten (W).
  • Filters: Mo, Rh, Aluminium (Al).

  ⭐ Molybdenum (Mo) target/filter combination is optimal for average breast thickness due to its characteristic X-rays (17.5 & 19.6 keV).

  • Small focal spot (0.3 mm routine; 0.1 mm magnification) for high resolution.
• Compression: Essential for image quality.
  • ↓Thickness, ↓scatter, ↓motion, ↓dose; separates tissues.
• Grids: Anti-scatter; improve contrast.
• AEC: Automatic Exposure Control for consistent image density.

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Standard Projections - Two-Angle Truth

• Two views/breast for 3D localization.
• 1. Craniocaudal (CC) View:
  • Beam: Superior → Inferior.
  • Shows: Medial vs. Lateral position.
  • Adequacy: Pectoral muscle (~30%); PNL visualized.
• 2. Mediolateral Oblique (MLO) View:
  • Beam: Medial → Lateral, angled 45-60°.
  • Shows: Superior vs. Inferior position; most tissue.

  ⭐ In an adequate MLO view, the pectoral muscle should be visible to the level of the posterior nipple line (PNL) or deeper.

  • Adequacy: Inframammary fold (IMF) open.
• "Two-Angle Truth": Differentiates lesions vs. superimposition.

Special Techniques - Problem Solvers Pro

• Magnification Views (M-views):
  • Details calcifications & mass margins.
  • Small focal spot, air gap. ↑Resolution, ↓scatter.
• Spot Compression:
  • Displaces tissue, clarifies margins, checks pliability.
  • Focal compression.
• Rolled Views (e.g., RM, RL):
  • Localizes lesions, separates tissue.
• Exaggerated Craniocaudal (XCCL, XCCM):
  • Visualizes extreme lateral/medial tissue.
• Cleavage View (CV):
  • Images deep medial breast.
• Digital Breast Tomosynthesis (DBT):
  • 3D mammography; thin slices.
  • ↓Overlap, ↑detection, ↓recall.

  ⭐ Digital Breast Tomosynthesis (DBT) improves lesion detection and characterization by reducing tissue overlap, especially in dense breasts.

• Contrast-Enhanced Mammography (CEM):
  • Functional; contrast highlights neovascularity.
  • Dual-energy subtraction.

Quality & Safety - Sharp & Shielded

• Image Sharpness (Quality):
  • Focal Spot: Small (0.3mm std, 0.1mm mag) for ↑spatial resolution.
  • Compression: Key for ↓motion blur, ↓scatter, ↓superimposition, ↓geometric unsharpness, ↓dose, ↑contrast.
  • Anti-scatter Grid: ↑contrast (↓scatter); may ↑dose by ~2x.
  • kVp: 25-35 kVp; impacts contrast & penetration.
  • Target/Filter: Mo/Mo (fatty), Mo/Rh, Rh/Rh, W/Rh (dense/digital).
• Radiation Safety (Shielded):
  • ALARA principle (As Low As Reasonably Achievable).
  • Average Glandular Dose (AGD):

    ⭐ Average Glandular Dose (AGD) per view in mammography should ideally be less than 3 mGy with a grid.

  • AGD factors: breast thickness/composition, compression, kVp, mAs, grid use.
  • QC: Regular phantom tests, dose audits. Staff shielding.

High‑Yield Points - ⚡ Biggest Takeaways

• Standard views: Craniocaudal (CC) and Mediolateral Oblique (MLO) form the baseline.
• MLO view: Paramount for visualizing most breast tissue, including axillary tail and pectoral muscle.
• CC view: Best depicts medial and extreme lateral lesions with superior-inferior compression.
• Adequate compression: Crucial for reducing motion blur, radiation dose, and separating overlapping tissues.
• Magnification views: Essential for detailed analysis of microcalcifications and mass characteristics.
• Digital Breast Tomosynthesis (DBT/3D): Significantly improves cancer detection, reduces false positives/recalls.