Perils and pitfalls of magnetic resonance imaging in the diagnosis of multiple sclerosis. The Rochester-Toronto MRI Study Group.

Purpose. Magnetic resonance imaging (MRI) has come to assume a position of major importance in the diagnostic process for multiple sclerosis (MS). The authors believe that a tendency toward overreliance on MRI results in isolation from clinical findings continues to result in both false-positive and false-negative diagnostic errors. Methods. To evaluate this, MRI results in newly referred patients with clinical findings suggestive, but not diagnostic, for MS, were studied prospectively. Results. Of 99 consecutive referrals for suspected MS, there were 3 false-positive diagnoses of MS and 7 false-negatives, when the MRIs were read in isolation from specific clinical data. None of the scans in the false-negative groups were normal. Representative images of both groups are provided. Conclusion. In newly referred patients who fall short of criteria for definite MS, it remains dangerous for both clinicians and radiologists to rely too heavily only on MRI results.