title: Choline and creatine are not reliable denominators for calculating metabolite ratios in acute ischemic stroke.
abstract: OBJECTIVE
  Choline and creatine are commonly used as denominators for other metabolites in ischemic stroke spectroscopy, assuming that they do not change. We investigated their concentration variation over time after stroke.
  
  
  METHODS
  Choline and creatine concentrations were measured by proton MR spectroscopic imaging in 51 patients at 5 times up to 3 months after stroke.
  
  
  RESULTS
  Choline and creatine levels changed significantly in the ischemic region. Choline was significantly reduced during the first 2 weeks after stroke onset (P=0.034). Creatine was significantly reduced during the whole period of the study (P=0.011).
  
  
  CONCLUSIONS
  Choline and creatine concentrations are not reliable denominators for metabolite ratios in acute stroke because their levels vary significantly in ischemic brain regions.
authors.affiliation: University of Edinburgh, Division of Clinical Neurosciences, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK. s.m.maniega@ed.ac.uk
authors.forename: Susana
authors.initials: S
authors.lastname: Muñoz Maniega
authors.forename: Vera
authors.initials: V
authors.lastname: Cvoro
authors.forename: Paul A
authors.initials: PA
authors.lastname: Armitage
authors.forename: Ian
authors.initials: I
authors.lastname: Marshall
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bastin
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001921:Brain / Q000098:blood supply / Q000378:metabolism* / Q000503:physiopathology; D002545:Brain Ischemia / Q000175:diagnosis / Q000378:metabolism*; D002794:Choline / Q000032:analysis / Q000378:metabolism*; D003401:Creatine / Q000032:analysis / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D015203:Reproducibility of Results; D020521:Stroke / Q000175:diagnosis / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D003401:Creatine; D002794:Choline