Publications (2)5.89 Total impact
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Article: Glatiramer acetate recovers microscopic tissue damage in patients with multiple sclerosis. A case-control diffusion imaging study.
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ABSTRACT: Traditional magnetic resonance imaging (MRI) techniques have contributed to the management of multiple sclerosis (MS) but are limited in their ability to detect neuronal damage. Advanced MRI metrics provide assessment of microscopic neuronal changes; however, few studies have examined the effects of MS therapies on these measures. This prospective, open-label, observational study evaluated the effect of subcutaneous glatiramer acetate (GA) 20mg/day on the 1- and 2-year changes in diffusion-weighted imaging (DWI) measures in patients with relapsing-remitting (RR) MS and in age- and sex-matched healthy controls (HC). Inclusion criteria were age 18-65, RR disease course, expanded disability status scale (EDSS) score ≤5.5 and disease duration<20 years. MS patients and HC underwent 1.5T MRI scans and clinical examinations at baseline and at 1- and 2-year follow-up. Nineteen RRMS patients and 16 HC completed the 1-year follow-up and 16 MS patients and 13 HC the 2-year follow-up of the study. In MS patients, treatment with GA promoted recovery of DWI mean parenchymal diffusivity (MPD) at year 1 (-7.1%, p=0.007) and at year 2 (-10.1%, p=0.028). The recovery of DWI MPD was significantly higher in MS patients compared to HC at year 1 (p=0.01) and year 2 (p<0.001). GA promoted recovery of DWI entropy at 2 years (-1.2%, p=0.018). No significant DWI MPD and entropy changes were observed in HC over the follow-up. No significant deterioration in magnetization transfer ratio occurred over the follow-up in MS patients and HC. Patients on GA and HC did not develop significant global or regional atrophy over 2 years. GA significantly improved microscopic tissue damage in the brain, as measured by DWI over the 1- and 2-year follow-up.Pathophysiology 02/2011; 18(1):61-8. -
Article: Signal abnormalities on 1.5 and 3 Tesla brain MRI in multiple sclerosis patients and healthy controls. A morphological and spatial quantitative comparison study.
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ABSTRACT: Previous studies in patients with multiple sclerosis (MS) revealed increased lesion count and volume on 3 T compared to 1.5 T. Morphological and spatial lesion characteristics between 1.5 T and 3 T have not been examined. The aim of this study was to investigate the effect of changing from a 1.5 T to a 3 T MRI scanner on the number, volume and spatial distribution of signal abnormalities (SA) on brain MRI in a sample of MS patients and normal controls (NC), using pair- and voxel-wise comparison procedures. Forty-one (41) MS patients (32 relapsing-remitting and 9 secondary-progressive) and 38 NC were examined on both 1.5 T and 3 T within one week in random order. T2-weighted hyperintensities (T2H) and T1-weighted hypointensities (T1H) were outlined semiautomatically by two operators in a blinded fashion on 1.5 T and 3 T images. Spatial lesion distribution was assessed using T2 and T1 voxel-wise SA probability maps (SAPM). Pair-wise analysis examined the proportion of SA not simultaneously outlined on 1.5 T and 3 T. A posteriori unblinded analysis was conducted to examine the non-overlapping identifications of SA between the 1.5 T and 3 T. For pair-wise T2- and T1-analyses, a higher number and individual volume of SA were detected on 3 T compared to 1.5 T (p<0.0001) in both MS and NC. Logistic regression analysis showed that the likelihood of missing SA on 1.5 T was significantly higher for smaller SA in both MS and NC groups. SA probability map (SAPM) analysis revealed significantly more regionally distinct spatial SA differences on 3 T compared to 1.5 T in both groups (p<0.05); these were most pronounced in the occipital, periventricular and cortical regions for T2H. This study provides important information regarding morphological and spatial differences between data acquired using 1.5 T and 3 T protocols at the two scanner field strengths.NeuroImage 04/2009; 47(4):1352-62. · 5.89 Impact Factor
