OCR GCSE Physics B · J259
Paper 1, Paper 2
Revise: Medical Uses of Nuclear RadiationA gamma-emitting tracer is useful because gamma rays can pass out of the body to reach a gamma camera. The resulting image shows the tracer's distribution: an area of unusually high or low uptake may indicate that the tissue is behaving differently. The tracer should have a suitably short half-life, so its activity does not remain high for longer than needed to obtain the image.