Brain MRI Lesion Load at 1.5T and 3T versus Clinical Status in Multiple Sclerosis

BACKGROUND/PURPOSE To assess correlation between brain lesions and clinical status with 1.5T and 3T magnetic resonance imaging (MRI). METHODS Brain MRI fluid-attenuated inversion-recovery (FLAIR) sequences were performed in 32 multiple sclerosis (MS) patients. Expanded Disability Status Scale (EDSS) score (mean +/- standard deviation) was 2 +/- 2.0 (range 0-8), disease duration 9.3 +/- 8.0 (range .8-29) years. RESULTS FLAIR lesion volume (FLLV) at 3T was higher than at 1.5T (P = .01). Correlation between 1.5T FLLV and EDSS score was poor, while 3T FLLV correlated moderately and significantly (r(s) = .39, P = .03). When controlling for age and depression, correlations between FLLV and cognitive measures were significant at 1.5T for the Judgment of Line Orientation test (JLO) (r(s) = -.44, P = .05), the Symbol Digit Modalities Test (SDMT) (r(s) = -.49, P = .02), and the California Verbal Learning Test Delayed Free Recall (CVLT DR) (r(s) = -.44, P = .04). Correlations at 3T were also significant for these tests, but of greater magnitude: JLO (r(s) = -.70, P = .0005), SDMT (r(s) = -.73, P = .0001), CVLT DR (r(s) = -.061, P = .003). Additional significant correlations obtained only at 3T included the 2 second-paced auditory serial addition test (r(s) = -.55, P = .01), the Brief Visuospatial Memory Test-Delayed Free Recall (r(s) = -.56, P = .007), and the California Verbal Learning Test Total Recall (r(s) = -.42, P = .05). CONCLUSION MRI at 3T may boost sensitivity and improve validity in MS brain lesion assessment.