OBJECTIVES: Multiple sclerosis lesions appear as areas of high signal on T2 weighted MRI. A proportion of these lesions, when viewed on T1 weighted MRI, appear hypointense compared with surrounding white matter. These hypointense T1 lesions are thought to represent areas of greater tissue damage compared with the more non-specific, total T2 lesion load. This study aimed to better characterise the properties of high signal T2 lesions with differing appearances on T1 weighted MRI using quantitative MR techniques. METHODS: Eleven patients with secondary progressive multiple sclerosis were studied. Two high signal T2 lesions were selected from each patient-one of which appeared hypointense and one isointense on a T1 weighted image. A voxel was positioned around each lesion and for this volume of brain the metabolite concentrations were estimated using proton MR spectroscopy ((1)H-MRS) and the T1 relaxation time within each voxel calculated from a T1 map generated using a multislice technique. RESULTS: Compared with isointense T1 lesions, hypointense T1 lesions exhibited a significantly lower absolute concentration of N-acetyl derived metabolites (tNAA) and a significantly higher absolute concentration of myo-inositol (Ins). T1 relaxation time correlated significantly with both tNAA (r=-0.8, p < 0.001) and Ins (r=0.5, p=0. 012). There was no correlation between T1 relaxation times and creatine/phosphocreatine or choline containing compounds. CONCLUSIONS: Prolonged T1 relaxation times seem to reflect the severity of axonal damage or dysfunction (inferred by a low tNAA) and possibly also gliosis (inferred by a high Ins) in chronic multiple sclerosis lesions.
OBJECTIVES: Multiple sclerosis lesions appear as areas of high signal on T2 weighted MRI. A proportion of these lesions, when viewed on T1 weighted MRI, appear hypointense compared with surrounding white matter. These hypointense T1 lesions are thought to represent areas of greater tissue damage compared with the more non-specific, total T2 lesion load. This study aimed to better characterise the properties of high signal T2 lesions with differing appearances on T1 weighted MRI using quantitative MR techniques. METHODS: Eleven patients with secondary progressive multiple sclerosis were studied. Two high signal T2 lesions were selected from each patient-one of which appeared hypointense and one isointense on a T1 weighted image. A voxel was positioned around each lesion and for this volume of brain the metabolite concentrations were estimated using proton MR spectroscopy ((1)H-MRS) and the T1 relaxation time within each voxel calculated from a T1 map generated using a multislice technique. RESULTS: Compared with isointense T1 lesions, hypointense T1 lesions exhibited a significantly lower absolute concentration of N-acetyl derived metabolites (tNAA) and a significantly higher absolute concentration of myo-inositol (Ins). T1 relaxation time correlated significantly with both tNAA (r=-0.8, p < 0.001) and Ins (r=0.5, p=0. 012). There was no correlation between T1 relaxation times and creatine/phosphocreatine or choline containing compounds. CONCLUSIONS: Prolonged T1 relaxation times seem to reflect the severity of axonal damage or dysfunction (inferred by a low tNAA) and possibly also gliosis (inferred by a high Ins) in chronic multiple sclerosis lesions.
Authors: L Truyen; J H van Waesberghe; M A van Walderveen; B W van Oosten; C H Polman; O R Hommes; H J Adèr; F Barkhof Journal: Neurology Date: 1996-12 Impact factor: 9.910
Authors: C A Davie; G J Barker; A J Thompson; P S Tofts; W I McDonald; D H Miller Journal: J Neurol Neurosurg Psychiatry Date: 1997-12 Impact factor: 10.154
Authors: J H Simon; L D Jacobs; M Campion; K Wende; N Simonian; D L Cookfair; R A Rudick; R M Herndon; J R Richert; A M Salazar; J J Alam; J S Fischer; D E Goodkin; C V Granger; M Lajaunie; A L Martens-Davidson; M Meyer; J Sheeder; K Choi; A L Scherzinger; D M Bartoszak; D N Bourdette; J Braiman; C M Brownscheidle; R H Whitham Journal: Ann Neurol Date: 1998-01 Impact factor: 10.422
Authors: Alexandra van Wijnen; Franca Petrov; Michelle Maiworm; Stefan Frisch; Christian Foerch; Elke Hattingen; Helmuth Steinmetz; Johannes C Klein; Ralf Deichmann; Marlies Wagner; René-Maxime Gracien Journal: Eur Radiol Date: 2019-10-10 Impact factor: 5.315
Authors: Ivan I Kirov; Shu Liu; Assaf Tal; William E Wu; Matthew S Davitz; James S Babb; Henry Rusinek; Joseph Herbert; Oded Gonen Journal: Hum Brain Mapp Date: 2017-05-19 Impact factor: 5.038
Authors: Belinda S Y Li; Juleiga Regal; Brian J Soher; Lois J Mannon; Robert I Grossman; Oded Gonen Journal: AJNR Am J Neuroradiol Date: 2003-01 Impact factor: 3.825