The diagnostic and therapeutic impact of MRI: an observational multi-centre study

AIM: To provide information about the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and to compare the findings across diagnos tic groups. MATERIALS AND METHODS: A prospective, observational study of 2017 consecuti ve referrals for MRI of the head, spine or knee at four imaging centres, Cl inicians completed questionnaires before MRI stating initial diagnoses, dia gnostic confidence and treatment plans. After imaging, a second questionnai re evaluated clinicians' revised diagnosis and treatment plans in the light of imaging findings. patients were grouped into nine diagnostic categories for analysis. Comparison between pre- and post-imaging was used to assess the diagnostic and therapeutic impact of MRI, RESULTS: In seven of nine diagnostic groups MRI findings were associated wi th a diagnostic impact. Diagnoses were revised or discarded following norma l MR findings and diagnostic confidence was increased by confirmative MR fi ndings. There was no statistically significant diagnostic impact for suspec ted pituitary or cerebello-pontine angle lesions. In five of nine diagnosti c groups (knee meniscus, knee ligament, multiple sclerosis, lumbar and cerv ical spine) MRI findings had a clear impact on treatment plans. CONCLUSION: This study demonstrates that in most diagnostic categories, MRI influences diagnosis and treatment. However, experimental studies are need ed to prove that these diagnostic and therapeutic impacts lead to improved health. (C) 2000 The Royal College of Radiologists.