Exam-style question
Try this first
For Half-life in medicine, which option best uses tracer half-life choice to answer this objective: Calculate activity changes using half-life.?.
- A.Use tracer half-life choice: balancing detectable count rate against patient exposure, so the answer is anchored to tracer suitability.
- B.Use a clinical description only, without naming the measured physical signal.
- C.Assume all tissue produces the same detector response, so no useful contrast is formed.
- D.Ignore the limitation or safety factor and treat the method as risk-free.
Model answer
What a good answer should say
- The correct option is Use tracer half-life choice: balancing detectable count rate against patient exposure, so the answer is anchored to tracer suitability.
Explanation
Why this works
It is correct because tracer half-life choice gives a specific physical mechanism and connects the detector or image evidence to the objective. The other options are incorrect because they either avoid the measured signal, remove contrast or detection detail, or ignore a limitation that AQA medical physics answers should consider.
Common mistake
No common mistake is linked to this question yet.