Correlation of magnetization transfer ratio histogram parameters with neuropsychiatric systemic lupus erythematosus criteria and proton magnetic resonance spectroscopy: association of magnetization transfer ratio peak height with neuronal and cognitive dysfunction.

OBJECTIVE: To investigate whether, in neuropsychiatric systemic lupus erythematosus (NPSLE) patients, magnetization transfer ratio (MTR) histogram parameters are related to neurochemical findings obtained using proton magnetic resonance spectroscopy (1H-MRS) and to determine whether MTR histogram changes are linked to specific SLE and NPSLE characteristics.
METHODS: Eighteen SLE patients (15 female, 3 male; mean +/- SD age 42.8 +/- 12.8 years), 34 NPSLE patients (32 female, 2 male; mean +/- SD age 35.9 +/- 12.2 years), and 15 healthy controls (14 female, 1 male; mean +/- SD age 44.7 +/- 9.6 years) underwent magnetization transfer imaging and 1H-MRS. Whole-brain MTR histogram parameters were associated with 1H-MRS metabolite ratios, certain SLE criteria, and neuropsychiatric syndromes.
RESULTS: No differences were found in the MTR histogram parameters between SLE patients and NPSLE patients. NPSLE patients had a lower MTR histogram peak height than did the healthy controls. The MTR histogram peak height and the mean height were significantly associated with the N-acetylaspartate to creatinine ratio, suggesting neuronal dysfunction. Of all SLE criteria, renal dysfunction and arthritis were associated with MTR histogram parameters. After corrections for age, sex, and these SLE criteria, of the various neuropsychiatric syndromes only cognitive dysfunction was associated with the MTR histogram peak height.
CONCLUSION: The MTR peak height is lower in NPSLE patients than in healthy controls. MTR peak height reflects neuronal dysfunction, as detected by 1H-MRS. Furthermore, the MTR peak height is associated with cognitive dysfunction but not with the other neuropsychiatric syndromes evaluated in our study.