Spinal cord lesions and clinical status in multiple sclerosis: A 1.5 T and 3 T MRI study

Abstract

Objective Assess the relationship between spinal cord T2 hyperintense lesions and clinical status in multiple sclerosis (MS) with 1.5 and 3 T MRI. Methods Whole cord T2-weighted fast spin-echo MRI was performed in 32 MS patients [Expanded Disability Status Scale (EDSS) score (mean ± SD: 2 ± 1.9), range 0–6.5]. Protocols at 1.5 T and 3 T were optimized and matched on voxel size. Results Moderate correlations were found between whole cord lesion volume and EDSS score at 1.5 T ( r s = .36, p = 0.04), but not at 3 T ( r s = 0.13, p = 0.46). Pyramidal Functional System Score (FSS) correlated with thoracic T2 lesion number ( r s = .46, p = 0.01) and total spinal cord lesion number ( r s = 0.37, p = 0.04) and volume ( r s = 0.37, p = 0.04) at 1.5 T. Bowel/bladder FSS correlated with T2 lesion volume and number in the cervical, thoracic, and total spine at 1.5 T ( r s 0.40–0.57, all p < 0.05). These MRI–FSS correlations were non-significant at 3 T. However, these correlation coefficients did not differ significantly between platforms (Choi's test p > 0.05). Correlations between whole cord lesion volume and timed 25-foot walk were non-significant at 1.5 T and 3 T ( p > 0.05). Lesion number and volume did not differ between MRI platforms in the MS group ( p > 0.05). Conclusions Despite the use of higher field MRI strength, the link between spinal lesions and MS disability remains weak. The 1.5 T and 3 T protocols yielded similar results for many comparisons.