title: Longitudinal quantitative MRI assessment of cortical damage in multiple sclerosis: A pilot study.
abstract: Quantitative MRI (qMRI) allows assessing cortical pathology in multiple sclerosis (MS) on a microstructural level, where cortical damage has been shown to prolong T1-relaxation time and increase proton density (PD) compared to controls. However, the evolution of these changes in MS over time has not been investigated so far. In this pilot study we used an advanced method for the longitudinal assessment of cortical tissue change in MS patients with qMRI in comparison to cortical atrophy, as derived from conventional MRI.
  
  
  
  Twelve patients with relapsing-remitting MS underwent 3T T1/PD-mapping at two timepoints with a mean interval of 12 months. The respective cortical T1/PD-values were extracted from the middle of the cortical layer and the cortical thickness was measured for surface-based identification of clusters with increasing/decreasing values.
  
  
  
  Statistical analysis showed clusters with increasing PD- and T1-values over time (annualized rate for T1/PD increase in these clusters: 3.4 ± 2.56% for T1, P = 0.0007; 2.3 ± 2.59% for PD, P = 0.01). Changes are heterogeneous across the cortex and different patterns of longitudinal PD and T1increase emerged. Analysis of the cortical thickness yielded only one small cluster indicating a decrease of cortical thickness.
  
  
  
  Changes of cortical tissue composition in MS seem to be reflected by a spatially inhomogeneous, multifocal increase of the PD values, indicating replacement of neural tissue by water, and of the T1-relaxation time, a surrogate of demyelination, axonal loss, and gliosis. qMRI changes were more prominent than cortical atrophy, showing the potential of qMRI techniques to quantify microstructural alterations that remain undetected by conventional MRI.
  
  
  
  1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1485-1490.
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: René-Maxime
authors.initials: RM
authors.lastname: Gracien
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Reitz
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Stephanie-Michelle
authors.initials: SM
authors.lastname: Hof
authors.affiliation: Department of Neurology, Johannes Gutenberg University, Mainz, Germany.|Neuroimaging Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Fleischer
authors.affiliation: Department of Neurology, Johannes Gutenberg University, Mainz, Germany.|Neuroimaging Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Amgad
authors.initials: A
authors.lastname: Droby
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Wahl
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.
authors.forename: Helmuth
authors.initials: H
authors.lastname: Steinmetz
authors.affiliation: Department of Neurology, Johannes Gutenberg University, Mainz, Germany.|Neuroimaging Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Sergiu
authors.initials: S
authors.lastname: Groppa
authors.affiliation: Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Deichmann
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.|Nuffield Department of Clinical Neurosciences, University of Oxford, UK.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Klein
mesh_terms: D000328:Adult; D001284:Atrophy; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000293:injuries / Q000503:physiopathology*; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010865:Pilot Projects
keywords: PD; T1; gray matter; longitudinal; multiple sclerosis (MS); quantitative MRI