A one year study of new lesions in multiple sclerosis using monthly gadolinium enhanced MRI: Correlations with changes of T2 and magnetization transfer lesion loads

In this study, 14 patients with either relapsing-remitting or secondary progressive multiple sclerosis (MS) were scanned monthly using gadolinium enhanced magnetic resonance imaging (MRI), At the start of the study and at 1 year follow up, T2-weighted and magnetization transfer (MT) scans were also performed. The correlation between the frequency and extent of enhancement and changes of lesion load over a 1 year period on Ta-weighted and MT images were assessed. For all patients, and for the relapsing-remitting patients only, the number and volume of enhancing lesions per month showed no significant correlation with the change between baseline and 1 year follow up of lesion volumes on T2 and MT images. However, strong correlations were found between the number and volume of gadolinium enhancing lesions with changes of T2 (r=0.93, P=0.02) and MT (r=0.82, P=0.04) lesion loads in patients with secondary progressive MS. Strong correlations were also found between the lesion loads on T2-weighted scans and on MT images both at baseline and at 1 year follow up (r=0.83, P=0.003). In addition, the changes in lesion load over 1 year, detected using the two techniques, were moderately correlated (r=0.51, P=0.05). This study provides further evidence that the pathological processes in MS are at different stages in relapsing-remitting and secondary progressive MS. It also suggests that the effectiveness of recovery mechanisms within lesions might be one of the major factors responsible for such a difference. (C) 1998 Elsevier Science B.V. All rights reserved.