<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pelletier, D.</style></author><author><style face="normal" font="default" size="100%">Nelson, S.J.</style></author><author><style face="normal" font="default" size="100%">Grenier, D.</style></author><author><style face="normal" font="default" size="100%">Lu, Y.</style></author><author><style face="normal" font="default" size="100%">Genain, C.</style></author><author><style face="normal" font="default" size="100%">Goodkin, D.E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">3-D echo planar 1HMRS imaging in MS: metabolite comparison from supratentorial vs. central brain</style></title><secondary-title><style face="normal" font="default" size="100%">Magn Reson Imaging</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">categ_st2i</style></keyword><keyword><style  face="normal" font="default" size="100%">imagerie_RMN_optique</style></keyword><keyword><style  face="normal" font="default" size="100%">Méthodes et systèmes en IRM et optique</style></keyword><keyword><style  face="normal" font="default" size="100%">reseau_international</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Oct</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">8</style></number><volume><style face="normal" font="default" size="100%">20</style></volume><pages><style face="normal" font="default" size="100%">599–606</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">To determine if metabolite ratios as measured by 3-dimensional echo planar spectroscopy imaging (3D-EPSI) from central brain regions of interest (ROI) centered at the corpus callosum reflect imaging metrics of large volumes of supratentorial brain (STB) from patients with multiple sclerosis. METHODS: 48 MS patients with relapsing-remitting, secondary progressive, and primary progressive disease underwent a 3D-EPSI sequence covering large volumes of STB. Metabolite ratios were first estimated from all voxels within a STB mask using a linear regression of N-acetylaspartate (NAA) over Creatine (Cr), NAA over choline (Cho) and Cho over Cr. Secondly, spectroscopic voxels from a central brain (CB) ROI centered at the corpus callosum were selected within the STB. Ratios were compared using Bland-Altman regression analysis and Spearman's correlation coefficients between STB versus central brain. Ratios from studied ROIs were correlated with the EDSS and compared to normal controls. RESULTS: Very strong correlations ranging from 0.884 and 0.938 (p &lt; 0.0001) were found for all metabolite ratios between STB versus central brain. NAA/Cr ratios were similarly and negatively correlated with the EDSS across all ROIs, trends ranging from -0.257 to -0.314 (p &lt; 0.1). NAA/Cr from all MS patients was similarly decreased compared to controls across all ROIs (p &lt; 0.01). CONCLUSION: Metabolite ratios from a central brain ROI were statistically equivalent and highly correlated with ratios from the STB. The study of NAA/Cr using (1)HMRS from a central brain ROI centered at the corpus callosum seems to be representative of brainwide axonal changes in patients with MS</style></abstract></record></records></xml>