In radiography, the patient (body part being x-rayed) is the main source of which type of radiation?

• A. Scatter radiation
• B. Primary radiation
• C. Leakage radiation
• D. Gamma radiation

Answer: (A)

When the diagnostic x-ray beam hits the body, photons interact with tissues and change direction. These interactions—primarily Compton and other scatter processes—generate photons that exit the patient in many directions. Because these scattered photons originate from within the patient, the patient becomes the main source of scatter radiation in radiography. This scattered radiation is what can reach the image receptor in less controlled directions and also contribute to occupational exposure. Leakage radiation comes from the x-ray tube housing, and gamma radiation is associated with radioactive materials, not with standard diagnostic radiography.