Radiation principles
Ionising radiation carries risk; every exposure needs justification and optimisation. Know roles, training and local procedures under UK regulations.
Understand
Justification asks whether the expected clinical benefit outweighs radiation risk for this patient. Optimisation then keeps dose as low as reasonably practicable for the required diagnostic answer.
Assess
Identify the referrer, practitioner and operator roles under local IR(ME)R procedures, check pregnancy information where relevant and review existing images.
Apply
Record the indication and a clinical evaluation of every exposure. A technically excellent image without a justified question is still poor practice.
Key distinctions
UK ionising radiation rules separate referral, justification, exposure and clinical evaluation roles. Good practice includes training, equipment quality assurance and a record of findings. “As low as reasonably practicable” is applied after deciding an exposure is justified; the lowest-dose image is not useful if it cannot answer the clinical question.
Think through a case
A patient with asymptomatic teeth is sent for a panoramic radiograph “just in case”. Without a specific expected benefit, the exposure cannot be justified.
The distinction to remember
Do not confuse a low individual dose with permission to take routine, non-indicated images.
Test your recall
Why is a routine image without a clinical question inappropriate?
Show answer
It cannot be individually justified.