In-Depth Notes on Mammographic Positioning

Learning Outcomes

  • Identify basic procedures and recognized standards involved with breast imaging.
  • Describe the basic positions, projections, and techniques used for mammography and how they are accomplished.

What is a Routine Mammogram?

  • A routine mammogram is a two-projection study consisting of:
    • CC (Cranio-Caudal)
    • MLO (Mediolateral Oblique)
  • These two views complement each other, providing a complete image of breast tissue.

Guidelines for Positioning

  • Method Development:

    • Aim for excellent study production in 85% of patients.
    • Identify issues if higher redo/view rates occur and adjust methods accordingly.

  • Position Identification:

    • Use ACR standardized labeling for clarity across facilities.
    • Label images by direction of the x-ray beam, laterality, technique, and view (e.g., R M ML).

  • Patient Cooperation:

    • Engage the patient in the process and allow them some control over the examination, including compression levels.
    • Listen actively to patient concerns before, during, and after the procedure.

  • Sanitizing Imaging Surface:

    • Ensure comfort through appropriate posture and positioning.
    • Pendant positioning is recommended for proper imaging.

  • Mobility of the Breast:

    • Address skin wrinkles as they can obscure structures; smooth skin towards the nipple instead of pulling outwards.

  • Nipple in Profile:

    • Ensure the nipple is in profile to prevent edge enhancement effects that may obscure vital information.

  • Motion Management:

    • Look for blurring which can affect image interpretation. Common motion occurs in inferior-posterior and anterior-central areas of MLO projections.

  • Markers:

    • Use specialized markers for scars, moles, and lumps to ensure clarity of past conditions during imaging.

  • Breast Cushions:

    • Utilize breast cushions to enhance patient comfort and improve positioning.

  • Skin Detail Improvements:

    • Modern FFDM technology allows for better visualization of both skin and glandular tissues.

  • Compression Importance:

    • Compressing breast tissue helps reduce radiation dose and enhances image quality by minimizing motion and improving contrast.
    • Maintain even compression to prevent overexposure or underexposure issues.

  • Compression Paddles:

    • Various paddle shapes and sizes can enhance the imaging process and accommodate diverse patient anatomies.

  • Image Receptor Size:

    • Use appropriate bucky sizes (18 x 24 cm or 24 x 30 cm) tailored to patient breast size.

  • Magnification Mammography:

    • An invaluable tool for enhanced resolution, used for detecting and characterizing breast abnormalities, although limitations in receptor size exist.

  • Respiration Control:

    • Instruct patients to stop breathing (rather than hold their breath) during exposure to maintain positioning.

  • Collimation:

    • Utilize tight collimation less often; modern techniques provide necessary contrast for mammograms.

  • Automatic Exposure Control (AEC):

    • Positioning glandular tissue over the AEC detector is crucial to avoid underexposure of critical areas.

Mammographic Projections

  • CC Projection (Cranio-Caudal):

    • Best for central, medial, and posteromedial aspects of the breast.
    • Patient positioning involves ensuring proper stance and posture to maximize tissue capture.

  • Variations of CC Projection:

    • Exaggerated Lateral Craniocaudal (XCCL): Focus on lateral tissue imaging.
    • Elevated Craniocaudal Projection: Designed to visualize superior lesions, often not apparent in standard CC views.
    • Caudal-Cranial Projection: Useful for superior abnormalities, especially in non-compliant patients.