Systemic lupus erythematosus: diagnostic application of magnetization transfer ratio histograms in patients with neuropsychiatric symptoms - initial results

PURPOSE: To explore the diagnostic potential of magnetization transfer ratio (MTR) histogram analysis in patients with neuropsychiatric systemic lupus erythematosus (SLE) by using multivariate discriminant analysis (MDA). MATERIALS AND METHODS: Volumetric magnetization transfer imaging was performed in nine patients with active non-thromboembolic, neuropsychiatric SLE, 10 patients with SLE who had had neuropsychiatric SLE previously, 10 patients with SLE but no history of neuropsychiatric SLE, 10 patients with inactive multiple sclerosis, and 10 healthy control subjects. For each subject, an MTR histogram of the whole brain was generated, and an MDA score was produced for each histogram. Each patient was assigned to a clinical subgroup on the basis of these MDA scores. For assignment, binary comparisons between subgroups were made. The accuracy of this classification method was assessed and compared with that of conventional MTR histogram analysis. RESULTS: With MDA, the success rate of binary classification was 60%-100%, depending on which two groups were compared. When the different clinical subgroups were separated, MDA parameters were always better than conventional MTR histogram parameters, with P values ranging from.05 to less than 1 x 10(-6) of those attained with the best conventional parameter. CONCLUSION: With MDA, MTR histograms of brain tissue may provide diagnostic information for individual patients in the clinical context of SLE.