I. Findings

  1. Seen on XRay films
  2. Loss of normal border between structures
    1. Different radiodensities form border on XRay
  3. Appearance of normally invisible outline

II. Interpretation

  1. Suggests infiltrates, fluids or air
  2. False positives
    1. Poor film technique (poor penetration or alignment)
    2. Normal anatomic variants

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