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Separate Physics · Paper 1 · Foundation + Higher · P4

Medical tracers and imaging

Key ideas1 of 3

Follow a substance inside the body

A medical tracer contains a small quantity of a suitable radioactive isotope. It is introduced into the body and follows a chosen biological pathway, allowing clinicians to study how an organ functions or where the substance travels. Radiation emitted from the tracer is detected outside the patient to build an image or record a pattern. The tracer’s chemistry must suit the part of the body being investigated.

A body outline with tracer symbols in an internal region and a gamma ray towards an external detector.

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Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · P4. Use alongside the shared P4 lessons.

AQA GCSE Physics 8463 · 4.4.3.3. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.