Clinical Question: Is magnetic resonance imaging (MRI) accurate for ruling in or ruling out multiple sclerosis (MS)?

Setting: Various (meta-analysis)

Study Design: Systematic review

Synopsis: The authors of this systematic review assembled 29 studies evaluating the diagnostic accuracy of MRI in patients suspected of having MS by searching 12 databases and the reference lists of identified studies. Two reviewers selected the studies for inclusion; 18 of the selected studies were cohort studies, and 11 were of lower-quality design (i.e., case-control). MRI was performed, a diagnosis was made, and patients were monitored for seven months to 14 years to determine whether they had clinically defined MS.

Bottom Line: MRI is not particularly useful for ruling in or ruling out MS. Relying on it to make the diagnosis will result in overdiagnosis of patients, and using it to rule out MS will cause a missed diagnosis in approximately one half of patients who eventually will be diagnosed clinically. (Level of Evidence: 1a)