Correlation between MRI and short-term clinical activity in multiple sclerosis: Comparison between standard- and triple-dose Gd-enhanced MRI

We assessed the relative sensitivities of standard (SD)and triple-dose (TD) gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) for detecting en hancing lesions in different phases of multiple sclerosis (MS) disease acti vity. Ten MS patients were studied with monthly brain MRI scans for a 3-mon th follow-up (i.e., 4 scans were obtained for each patient with both SD and TD). A total of 11 relapses were recorded and treated with shortterm high- dose steroid therapy. Enhancing lesion numbers and volumes were significant ly higher for TD vs. SD scans (p < 0.0001). For both Gd doses, the numbers and volumes of lesions were higher during clinical relapses; the difference s were statistically significant when comparing the results for scans obtai ned during and after a relapse. The gain in sensitivity of TD vs. SD scans for enhancing lesion detection was lower during relapses, whilst it was max imum after relapses, although these differences did not reach statistical s ignificance. Our data confirm the potential role of TD MRI for monitoring M S activity, since, with its higher sensitivity, it may detect more subtle b lood-brain barrier (BBB) damage. They also suggest that the degree of BBB d amage in individual lesions changes during different phases of disease acti vity.