Objective: Diagnostic technologies are often assessed merely by their accuracy, rather than by their impact on diagnosis and patient management. To this end the authors have undertaken a study to assess the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and arthrography of the shoulder for patients referred from a rheumatology clinic.
Methods and patients: Patients referred from a rheumatology clinic with symptoms warranting imaging of the shoulder were randomised to either MRI or arthrography. Data on the clinician's diagnostic confidence and management were recorded before and after imaging using questionnaires. Patients were followed-up at least 10 months after imaging to see how management plans evolved, and what proportion of patients required further imaging.
Results: Fifty three shoulders underwent imaging over a year and entered into the study; 29 randomised to MRI and 24 to arthrography. Both MRI and arthrography had a similar beneficial diagnostic impact in terms of clinical diagnoses (refuted and retained) and new diagnoses established. MRI and arthrography had a similar therapeutic impact, although MRI was associated with a significant shift towards surgical intervention.
Conclusion: MRI and arthrography a have similar diagnostic and therapeutic impact.