An evaluation of magnetic resonance imaging at The Royal North Shore Hospital of Sydney, 1986-1987.

The diagnostic accuracy and clinical utility have been evaluated of 2810 consecutive magnetic-resonance-imaging examinations that were performed on a 1.5-T Signa magnetic-resonance-imaging unit at The Royal North Shore Hospital of Sydney between November 1986 and December 1987. The average accuracy of magnetic resonance imaging was 80%, and ranged from 21%-98% in various brain-disease and spinal-disease categories, compared with the average provisional premagnetic-resonance-imaging diagnostic accuracy of 64%, and an average accuracy of computed tomography of 45%. Clinical follow-up at three months after magnetic-resonance-imaging investigation indicated that, as a result of the magnetic-resonance-imaging examination, patient management was altered in 70% of cases, and patient outcome was altered in 62% of cases.