Justification Principle — MFDS Part 1 MCQ
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Correct answer: D — Determining before exposure that the expected benefit outweighs the potential detriment
Explanation lettering: C = shown as A · E = shown as B · B = shown as C · A = shown as D · D = shown as E
A is correct. Under IR(ME)R, an individual radiographic exposure must be justified before it is performed. The practitioner determines whether the anticipated diagnostic benefit provides sufficient net benefit when balanced against the potential detriment, including radiation risk; relevant alternatives using less or no ionising radiation should also be considered. Selecting exposure factors to obtain adequate image quality with the lowest reasonably practicable dose is optimisation, not justification. Consent is a separate legal and ethical process. Image processing and positioning are practical aspects of producing a diagnostically acceptable radiograph and do not establish whether the exposure should be undertaken.
Reference: Department of Health and Social Care. Guidance to the Ionising Radiation (Medical Exposure) Regulations 2017, Regulation 11: justification of individual exposures. Updated 2024. https://www.gov.uk/government/publications/ionising-radiation-medical-exposure-regulations-2017-guidance/guidance-to-the-ionising-radiation-medical-exposure-regulations-2017