What does the anode heel effect cause variation in across the x-ray field?

What does the anode heel effect cause variation in across the x-ray field?

• A. Beam quantity across the x-ray field
• B. Beam energy spectrum
• C. Patient skin dose
• D. Receptor exposure uniformity

Answer: (A)

The anode heel effect creates a nonuniform photon flux across the beam because photons that travel toward the anode side pass through more of the anode material and are more attenuated, while photons toward the cathode side pass through less material and are less attenuated. This difference in attenuation causes the beam quantity (the number of photons exiting the tube) to vary across the field—higher on the cathode side and lower on the anode side. Clinically, this means the exposure is not uniform across the image unless adjustments are made. The energy spectrum can shift slightly due to differential attenuation, but the most noticeable and primary variation described by the heel effect is the beam quantity across the field. That’s why the best choice is beam quantity across the x-ray field.

The anode heel effect creates a nonuniform photon flux across the beam because photons that travel toward the anode side pass through more of the anode material and are more attenuated, while photons toward the cathode side pass through less material and are less attenuated. This difference in attenuation causes the beam quantity (the number of photons exiting the tube) to vary across the field—higher on the cathode side and lower on the anode side. Clinically, this means the exposure is not uniform across the image unless adjustments are made.

The energy spectrum can shift slightly due to differential attenuation, but the most noticeable and primary variation described by the heel effect is the beam quantity across the field. That’s why the best choice is beam quantity across the x-ray field.