title: The age dependence of T2 relaxation times of N-acetyl aspartate, creatine and choline in the human brain at 3 and 4T.
abstract: Knowledge of the T2 age dependence is of importance for MRS clinical studies involving subject groups with a wide age range. A number of studies have focused on the age dependence of T2 values in the human brain, with rather conflicting results. The aim of this study was to analyze the age dependence of T2 values of N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) in the human brain using data acquired at 3T and 4T and to assess the influence of the macromolecule (MM) baseline handling on the obtained results. Two distinct groups of young and elderly controls have been measured at 3T (TE = 30-540 ms, 9 young and 11 elderly subjects) and 4T (TE = 10-180 ms, 18 young and 14 elderly subjects) using single-voxel spectroscopy. In addition, MM spectra were measured from two subjects using the inversion-recovery technique at 4T. All spectra were processed with LCModel using basis sets with different MM signals (measured or simulated) and also with MM signals included for a different TE range. Individual estimated T2 values were statistically analyzed using the R programming language for the age dependence of T2 values as well as the influence of the MM baseline handling. A significant decrease of T2 values of NAA and Cr in elderly subjects compared with young subjects was confirmed. The same trend was observed for Cho. Significantly higher T2 values calculated using the measured MM baseline for all studied metabolites at 4T were observed for both young and elderly subjects. To conclude, while the handling of MM and lipid signals may have a significant effect on estimated T2 values, we confirmed the age dependence of T2 values of NAA and Cr and the same trend for Cho in the human brain. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Institute for Clinical and Experimental Medicine, MR-Unit, Department of Diagnostic and Interventional Radiology, Prague, Czech Republic.
authors.forename: F
authors.initials: F
authors.lastname: Jiru
authors.affiliation: Institute for Clinical and Experimental Medicine, MR-Unit, Department of Diagnostic and Interventional Radiology, Prague, Czech Republic.|International Clinical Research Center, Department of Imaging Methods, St Anne's University Hospital Brno, Brno, Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Skoch
authors.affiliation: Institute for Clinical and Experimental Medicine, MR-Unit, Department of Diagnostic and Interventional Radiology, Prague, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Wagnerova
authors.affiliation: Institute for Clinical and Experimental Medicine, MR-Unit, Department of Diagnostic and Interventional Radiology, Prague, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Dezortova
authors.affiliation: International Clinical Research Center, Department of Imaging Methods, St Anne's University Hospital Brno, Brno, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Viskova
authors.affiliation: Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Department of Auditory Neuroscience, Prague, Czech Republic.|First Faculty of Medicine, Charles University, Faculty Hospital Motol, Department of Otorhinolaryngology and Head and Neck Surgery, Prague, Czech Republic.
authors.forename: O
authors.initials: O
authors.lastname: Profant
authors.affiliation: Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Department of Auditory Neuroscience, Prague, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Syka
authors.affiliation: Institute for Clinical and Experimental Medicine, MR-Unit, Department of Diagnostic and Interventional Radiology, Prague, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Hajek
mesh_terms: D000367:Age Factors; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D055815:Young Adult
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline
keywords: MRS; T2 relaxation times of metabolites; age dependence of T2