Lesson Plan

• Describe the β⁺ decay process of PET tracers and the resulting positron emission.
• Explain how positron‑electron annihilation produces two 511 keV photons that are detected in PET.
• Interpret PET images by linking tracer distribution to metabolic activity.
• Calculate the relevance of half‑life values for common PET isotopes.

• Projector or interactive whiteboard
• PowerPoint slides with PET diagrams
• Printed handout of the PET tracer table
• Clicker/polling software for concept checks
• Worksheet for activity‑based calculations
• Short video of a PET scanner in operation

Begin with a striking image of a PET scan and ask students what they think creates the colourful patterns. Briefly recall how X‑rays are produced and link that to the need for a radioactive source in PET. State that by the end of the lesson they will be able to explain the complete chain from β⁺ decay to functional imaging.

1. Do‑now (5') – Quick quiz on X‑ray production and Bremsstrahlung vs. characteristic radiation.
2. Mini‑lecture (10') – Review β⁺ decay, positron travel, and annihilation photon creation.
3. Interactive diagram (8') – Students annotate a schematic of a PET scanner, labeling detector rings and back‑to‑back photons.
4. Group activity (12') – Analyse the provided tracer table; calculate remaining activity after one half‑life and discuss clinical uses.
5. Concept‑check (5') – Clicker questions on the relationship between tracer distribution and metabolic activity.
6. Summary & exit ticket (5') – Each student writes one sentence summarising why β⁺ decay is essential for PET imaging.

Recap the key steps: β⁺ decay → positron → annihilation → 511 keV photon pair → image reconstruction. Collect exit tickets to gauge understanding and assign a short homework: research one emerging PET tracer and prepare a one‑minute oral summary for the next class.