National audit of appropriate imaging

Aims: To audit the availability of imaging referral guidelines; vetting by radiologists of GP-initiated CT and MRI requests; and the achievement of appropriate imaging using retrospective assessment as a surrogate.

Materials and methods: A web-based questionnaire was distributed to imaging departments in the UK seeking awareness of guideline availability; the percentage of consecutive general practitioner (GP)-requested computed tomography (CT) and magnetic resonance imaging (MRI) investigations that showed evidence of vetting; and the percentage of procedures where retrospective assessment showed the investigation to be appropriate according to imaging referral guidelines.

Results: Replies were received from 88 departments covering 1700 of 2700 (63%) consultant radiologists practising in the UK. Regarding the availability of guidelines, approximately a third of respondents were not aware of guidelines being available to all radiologists and radiographers. The 68% level of availability (58/88 departments) is well below the standard of 100%. In keeping with the target of 95%, vetting of CT requests was shown in 1815/1890 (96%) and MRI in 1181/1250 (95%). Appropriateness of CT examinations was shown in 1746/1870 (93%) and MRI in 1154/1215 (95%), well above the target of 90%. The most common reason for an inappropriate investigation for both MRI and CT was the inability to affect patient management.

Conclusions: Although awareness of referral guidelines availability was limited at 68%, well below the 100% standard, the meticulous vetting of requests (shown in 95-96%) with the amendment or return of inappropriate requests (9-12%) enables a high level of appropriate imaging (93-95%) for GP-requested CT and MRI, thus making the best use of clinical radiology.