The authors report four cases in which magnetic resonance imaging (MRI)
provided diagnostic information not apparent by X-ray CAT in clinical
investigations of patients with neuropsychiatric disorders. The relative
capabilities and contraindications for MRI and CAT are reviewed. The
authors suggest that MRI is indicated 1) instead of CAT when there is
suspicion of neuropathology that is better visualized by MRI because of its
type or location and 2) after CAT when an atypical psychiatric symptom or
presentation has not been definitively evaluated by means of CAT.