Anode heel effect

• What is the anode heel effect?

  A radiographic phenomenon affecting X-ray intensity
• Why is the anode angled in general radiography?

  To increase heat absorption and spatial resolution
• What is the consequence of the angled anode on X-ray intensity?

  It causes variation in beam intensity across the field
• Which side of the X-ray beam has higher intensity?

  The cathode side
• Why are there fewer X-ray photons on the anode side?

  Photons are absorbed within the anode heel
• What does the anode heel effect result in?

  Decreased X-ray beam intensity on the anode side
• How can the anode heel effect be used advantageously in abdominal X-rays?

  Place the anode side over the upper abdomen
• What happens to the exposure when the anode side is over the upper abdomen?

  It allows for more even exposure to the receptor
• What effect does decreasing the anode angle have on the anode heel effect?

  It increases the anode heel effect
• How does a steeper anode angle affect X-ray photons?

  More X-rays get absorbed in the anode
• What is the relationship between anode angle and the heel effect?

  Inverse relationship
• How does changing the SID affect the anode heel effect?

  Decreasing SID increases the heel effect
• What happens when the field size is increased regarding the anode heel effect?

  It increases the anode heel effect
• What is the effect of using a large field size on X-ray exposure?

  Exposes receptor to more low intensity beam
• What are the factors that can increase the anode heel effect?

  • Decreased anode angle
  • Decreased SID
  • Increased field size
• What is the summary of the anode heel effect?

  • Change in beam intensity across X-ray field
  • Anode side has fewer photons
  • Cathode side has more photons
  • Use to advantage in patient positioning