The secondary protective barrier includes which forms of radiation?

• A. Leakage and scattered radiation
• B. Primary beam only
• C. Only leakage
• D. Only scattered radiation

Answer: (A)

The barrier that protects areas not in the primary beam must handle radiation coming from sources other than the direct beam. This includes leakage radiation, which escapes through the x-ray tube housing, and scatter radiation, which results when the primary photons interact with the patient or surrounding objects and change direction. Both leakage and scatter can travel in various directions, so the secondary protective barrier is designed to attenuate both forms. The primary barrier, by contrast, is the one in the path of the primary beam. So the forms of radiation included in the secondary barrier are leakage and scattered radiation.