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 3T 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 1.5T and 3T were optimized and matched on voxel size. Results Moderate correlations were found between whole cord lesion volume and EDSS score at 1.5T (rs =.36, p=0.04), but not at 3T (rs =0.13, p=0.46). Pyramidal Functional System Score (FSS) correlated with thoracic T2 lesion number (rs=.46, p=0.01) and total spinal cord lesion number (rs=0.37, p=0.04) and volume (rs=0.37, p=0.04) at 1.5T. Bowel/bladder FSS correlated with T2 lesion volume and number in the cervical, thoracic, and total spine at 1.5T (rs 0.400.57, all p<0.05). These MRI-FSS correlations were non-significant at 3T. 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 1.5T and 3T (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 1.5T and 3T protocols yielded similar results for many comparisons.