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.