A barrier used to attenuate stray radiation is termed?

• A. tertiary protective barrier
• B. secondary protective barrier
• C. primary protective barrier
• D. accessory barrier

Answer: (B)

Stray radiation is the scatter from the patient and leakage from the tube that escapes the primary beam path. To protect people in adjacent areas, we use a barrier specially designed to reduce this type of radiation. This barrier is the secondary protective barrier. It complements the primary barrier, which is built to withstand the full intensity of the primary beam, not the scattered or leaked photons. The secondary barrier is positioned and constructed to attenuate scatter and leakage to acceptable levels, keeping dose in non–target areas within limits. The terms tertiary barrier or accessory barrier aren’t used in the standard framework for shielding stray radiation in diagnostic radiography, so they don’t apply here.