What does primary radiation do?

What does primary radiation do?

• A. Travels from source to detector (useful)
• B. Changes direction during passage
• C. Originates from X-ray tube and is not the primary beam
• D. Is unaffected by patient tissues

Answer: (A)

Primary radiation is the useful x-ray beam produced by the tube and directed toward the image receptor. Its job is to travel from the source to the detector and form the radiographic image after passing through the patient, being attenuated by tissues along the way. The primary beam travels along its intended path until it interacts with matter; when photons interact, they can be scattered or absorbed, but those scattered photons are no longer part of the primary beam. Tissues do affect primary radiation through attenuation, reducing its intensity, which is how contrast is produced in the image. The other statements describe radiation produced after interactions (scatter) or assert properties that don’t apply to the primary beam itself.

Primary radiation is the useful x-ray beam produced by the tube and directed toward the image receptor. Its job is to travel from the source to the detector and form the radiographic image after passing through the patient, being attenuated by tissues along the way. The primary beam travels along its intended path until it interacts with matter; when photons interact, they can be scattered or absorbed, but those scattered photons are no longer part of the primary beam. Tissues do affect primary radiation through attenuation, reducing its intensity, which is how contrast is produced in the image. The other statements describe radiation produced after interactions (scatter) or assert properties that don’t apply to the primary beam itself.