Lesson Plan

• Describe what a radioactive tracer is and its role in medical imaging.
• Explain how tracers are combined with X‑ray based modalities (e.g., PET/CT) to provide functional and anatomical information.
• Identify key safety principles for handling radioactive tracers.
• Compare common tracers (¹⁸F‑FDG, ⁹⁹ᵐTc‑MIBI, ¹³¹I) in terms of half‑life and imaging modality.
• Evaluate the advantages of hybrid imaging over standalone X‑ray or tracer techniques.

• Projector and screen
• PowerPoint slides with X‑ray tube and tracer diagrams
• Handout summarising tracer types and safety rules
• Printed PET/CT sample images
• Clickers or response cards for quick checks
• Radiation‑safety posters

Begin with a striking image of a PET/CT scan and ask students what information each part provides. Recall previous learning on X‑ray production and its diagnostic uses. State that by the end of the lesson they will be able to explain how radioactive tracers add functional insight to anatomical X‑ray images.

1. Do‑now (5'): Quick quiz on bremsstrahlung and characteristic X‑rays.
2. Mini‑lecture (10'): Definition of radioactive tracers, examples, and how they are introduced into the body.
3. Interactive diagram activity (10'): Students label a PET/CT image, identifying functional vs. anatomical components.
4. Group case study (15'): Analyse a clinical scenario, choose an appropriate tracer and imaging modality, and justify the choice.
5. Safety discussion (5'): Review ALARA principles and specific handling guidelines for tracers.
6. Exit ticket (5'): Write one advantage of hybrid imaging over a single‑modality approach.

Summarise how tracers complement X‑ray techniques to give both functional and structural information. Collect exit tickets to gauge understanding and assign a short homework: research a recent clinical application of a radioactive tracer and prepare a one‑minute summary.