Using radiation on people carries an ethical duty to do it responsibly. The core principles: justification (only use radiation when the benefit clearly outweighs the risk), optimisation (use the least dose needed), and special care for those more vulnerable — children and pregnant people. Avoiding unnecessary and duplicate scans, and choosing radiation-free tests where possible, are part of that duty.
Key takeaways
- Justification: use radiation only when benefit clearly outweighs risk.
- Optimisation: use the least dose needed for a useful result.
- Special care for children and pregnant people.
- Avoiding unnecessary and duplicate scans is an ethical duty.
Radiation is a powerful diagnostic tool — but because it carries a small risk, using it on people brings an ethical responsibility to do so carefully. A few principles guide this, and they’re shared internationally and in Australia.
Justification: only when it’s worth it
The first ethical principle is justification: radiation should only be used when the benefit clearly outweighs the risk.[2] A scan that won’t change your care isn’t justified. This is why doctors think carefully before ordering imaging, and avoid unnecessary scans. (It’s worth remembering there’s also a real risk in not imaging — a missed diagnosis — which is part of the same balance.)[1]
Optimisation: the least dose needed
If a scan is justified, the next principle is optimisation — using the least radiation needed to get a useful result.[3] Doing a scan well at the lowest reasonable dose respects the person’s safety while still answering the clinical question.
Special care for the vulnerable
Ethics demands extra care for those more sensitive to radiation:[2]
- Children, whose growing tissues are more radiation-sensitive, have doses scaled down and radiation-free tests favoured.
- Pregnant people, where radiation-based scans are generally avoided unless necessary, and ultrasound or MRI is preferred.
Avoiding duplication and respecting choice
Repeating a scan that’s already been done — or doing one “just in case” — exposes someone to risk for no benefit, so avoiding duplicate imaging is part of the duty. So is being open with patients: explaining why a scan is needed, and what the alternatives are, so they can take part in the decision.[2]
Frequently asked questions
How do doctors decide a scan is ethical?
By justifying it (the benefit must outweigh the risk), optimising it (the least dose needed), taking special care with children and pregnancy, and avoiding unnecessary or duplicate scans.[2]
Can I question whether I really need a scan?
Yes — it’s reasonable to ask your doctor why a scan is needed, what it will change, and whether a radiation-free alternative exists. That conversation is part of the ethical use of imaging.[2]
Sources
- RadiologyInfo.org (RSNA & ACR) — Radiation Dose from X-Ray and CT Exams — www.radiologyinfo.org/en/info/safety-xray
- RANZCR / InsideRadiology — Radiation risk of medical imaging — www.insideradiology.com.au/radiation-risk/
- ARPANSA — Having a scan? A guide for medical imaging (2024) — www.arpansa.gov.au/sites/default/files/documents/2024-05/patienthandout.pdf
