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How does an X-ray work?

Medicine & HealthLesson on requestFree to read

Quick answer

An X-ray works by sending a beam of high-energy light through your body onto a detector. Dense tissue like bone absorbs more of the beam and shows up bright, while soft tissue lets more through and appears dark — producing a shadow image of what is inside.

Step by step

  1. An X-ray tube accelerates electrons into a metal target, releasing high-energy electromagnetic radiation.
  2. The beam passes through the body; dense material such as bone or metal absorbs more than soft tissue.
  3. A detector behind you records how much radiation made it through at each point.
  4. The result is a shadow image: bone bright, air and soft tissue darker.

People also ask

Why do bones show up white?
Calcium in bone is dense and absorbs more X-rays, so little reaches the detector there — which records as bright on the image.
Are X-rays safe?
A single medical X-ray uses a small dose, and the benefit usually outweighs the tiny added risk; technicians still minimize exposure and shield nearby areas.
How is a CT scan different?
A CT scan takes many X-ray images from different angles and combines them into detailed 3D cross-sections, rather than one flat shadow.