What term describes radiation not serving a purpose, including leakage and scatter?

• A. Direct Radiation
• B. Stray Radiation
• C. Background Radiation
• D. Ambient Radiation

Answer: (B)

Stray radiation describes photons that don’t contribute to forming the image. It includes radiation that leaks from the x-ray tube housing and scatter produced when the primary beam interacts with the patient or surrounding objects. This non-useful radiation adds dose to anyone in the room and can reduce image quality by adding fog or noise, which is why shielding, proper collimation, and good technique are important to keep it to a minimum.

Direct radiation is the useful primary beam intended to create the image. Background or ambient radiation refers to natural or environmental radiation present in the surroundings, not produced by the imaging procedure. That’s why stray radiation is the correct term for leakage and scatter.