Xray

XRay Interpretation

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XRay Interpretation, Radiographic Imaging, Radiography, XRay, Mach Band, Musculoskeletal XRay ABCs

  • Background
  1. Five Radiographic Densities (in order of increasing brightness)
    1. Air (e.g. lung, dark)
    2. Fat
    3. Fluid and soft tissue (e.g. heart)
    4. Bone or calcifications
    5. Metal or Contrast Material (very bright)
  2. Differences in radiographic density allows for differentiation of structures on XRay
    1. Adjacent objects with similar densities will have indistinct abbutting margins
    2. Blurred structural margin suggests an adjacent structure (Silhouette Sign)
  3. Image Geometry
    1. Orthogonal views (90 degrees) reduces distortion
    2. Objects further from the xray film are distorted
      1. Objects close to XRay film or cassette have sharp edges without significant magnification
      2. Objects further from XRay film or cassette have blurred edges and greater magnification
  4. Penetration
    1. Over-penetration: Dark films
    2. Under-penetration: White films
  5. Artifacts
    1. Mach Bands
      1. Optical Illusion that appears similar to a Fracture line at the interface between radiopaque objects
      2. Two superimposed structures (e.g. bone on bone) have slightly different shades of gray
  1. Unlike fluoroscopy or CT, single modern xray exposure risk is negligible (0.04 mSv)
    1. Single Xray exposure is equivalent to 10 days of environmental background Radiation Exposure
  2. Radiation Exposure is reduced even further with distance from XRay source (by inverse of square of distance)
    1. Distance 2 feet from XRay Source drops Radiation Exposure to 25% (compared with 1 foot distance)
    2. Distance 3 feet from XRay Source drops Radiation Exposure to 11% (compared with 1 foot distance)
    3. Distance 4 feet from XRay Source drops Radiation Exposure to 6.3% (compared with 1 foot distance)
    4. Distance 5 feet from XRay Source drops Radiation Exposure to 4% (compared with 1 foot distance)
  1. Check Metadata
    1. Patient Name and Identifiers
    2. Exam Date and Time
    3. Technician Notations (e.g. Expiration film)
  2. Patient Position
    1. Supine
    2. Semiupright
    3. Erect
  3. Patient Alignment
    1. Rotation
    2. Lordosis or kyphosis
  4. Systematic Review in General
    1. Prowl the film in systematic fashion (see xray findings below for specific approaches)
    2. View images adjusting brightness/contrast presets (e.g. bone window) and different magnification
  5. Systematic Review: Musculoskeletal XRay ABCs
    1. Adequacy and Alignment
    2. Bones
    3. Cartilage and Joints
    4. Soft tissue and spacing
  • Findings
  1. Head
    1. See Sinus XRay
    2. See Skull XRay
  2. Chest
    1. See Chest XRay
    2. See Chest XRay Interpretation
    3. See Chest XRay Changes Suggestive of Tb
    4. See Chest XRay in Asthma
    5. See Chest XRay in Congenital Heart Disease
    6. See Chest XRay in Congestive Heart Failure
    7. See Chest XRay in Pneumothorax
  3. Upper Extremity
    1. See Shoulder XRay
    2. See Elbow XRay
    3. See Wrist XRay
    4. See Hand XRay
  4. Lower Extremity
    1. See Pelvis XRay
    2. See Hip XRay
    3. See Knee XRay
    4. See Ankle XRay
    5. See Foot XRay
  5. Spine
    1. See Cervical Spine XRay
    2. See Thoracic Spine XRay
    3. See Lumbar Spine XRay
    4. See Scoliosis XRay
  6. Specific Conditions
    1. See XRay Changes in Rheumatic Conditions
    2. See Osteoarthritis XRay
    3. See Osteomyelitis XRay
    4. See Stress Fracture XRay