Correlation between enhancing lesion number and volume on standard and triple dose gadolinium-enhanced brain MRI scans from patients with multiple sclerosis

We investigated the correlations between numbers and volumes of multiple sc lerosis (RIS) lesions enhancing on standard dose (SD) and triple dose (TD) gadolinium (Gd)-enhanced brain magnetic resonance imaging (MRI) scans, to c larify whether the measurement of enhancing lesion volumes or the use of TD MRI give additional information which can not be obtained by counting enha ncing lesions on SD scans. SD and TD Gd-enhanced brain MRI scans were obtai ned every month for three months from 40 MS patients. The numbers of total and new enhancing lesions were counted, and the fetal volumes of enhancing lesions were measured from each of the four scans obtained with the two tec hniques, Univariate correlations between enhancing lesion numbers and volum es were assessed. The numbers of total and new enhancing lesions seen eithe r on SD or TD scans were significantly correlated (r = 0.91 and 0.93, respe ctively). The numbers and volumes of total enhancing lesions were significa ntly correlated on both SD (r = 0.90), and TD (r = 0.89) scans. Moderate co rrelations were found between the total number of enhancing lesions on SD s cans and the average difference between TD and SD scans for total enhancing lesion number (r = 0.66), and between the number of new enhancing lesions on SD scans and the average difference between TD and SD scans for new enha ncing lesion number (r = 0.50). Our findings indicate that, both on SD and TD MRI, the counts and the volumes of total and new enhancing lesions are h ighly correlated, and that lesion counting mag suffice to monitor MS activi ty. On the contrary, this study confirms the usefulness of TD MRI for a mor e complete assessment of the acute changes occurring in MS patients. (C) 19 99 Elsevier Science Inc.