title: Effects of contrast material on the metabolite ratios in single-voxel MR Spectroscopy of intraaxial brain tumors.
abstract: OBJECTIVE
  The purpose of our study was to determine whether the administration of contrast material affects the results of MR Spectroscopy (MRS) in different intraaxial brain tumors.
  
  
  METHODS
  Thirty-three patients (median range 46.72 ± 2.95, range 9-77) with intraaxial brain tumors underwent MRS before and 5 min after intravenous administration of gadolinium based contrast material at the standard dose of 0.1 mmol/kg (Gadodiamide or Gd-DOTA). Metabolite ratios (N-acetyl aspartate (NAA)/Creatine (Cr), Choline (Cho)/Cr, and NAA/Cho) were calculated.
  
  
  RESULTS
  There was no significant difference between the pre and postcontrast MRS spectra as regards to NAA/Cr (p:0.4), Cho/Cr (p:0.2), and NAA/Cho (p:0.2) ratios obtained from the intraaxial brain tumors.
  
  
  CONCLUSIONS
  Contrast material administration did not change the metabolite ratios of MRS. Contrast administration would be useful in guiding voxel localization in MRS evaluation of intraaxial brain tumors.
authors.affiliation: Bezmialem Vakif University, School of Medicine, Department of Radiology, İstanbul, Turkey. alpay_alkan@hotmail.com
authors.forename: Alpay
authors.initials: A
authors.lastname: Alkan
authors.forename: Veysel
authors.initials: V
authors.lastname: Burulday
authors.forename: Namik
authors.initials: N
authors.lastname: Oztanir
authors.forename: Metin
authors.initials: M
authors.lastname: Dogan
authors.forename: Mehmet Fatih
authors.initials: MF
authors.lastname: Erbay
authors.forename: Ayhan
authors.initials: A
authors.lastname: Kocak
authors.forename: Ayse
authors.initials: A
authors.lastname: Aralasmak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016477:Artifacts; D014408:Biomarkers, Tumor / Q000032:analysis*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D002648:Child; D003287:Contrast Media / Q000009:adverse effects; D005260:Female; D019786:Gadolinium DTPA / Q000009:adverse effects*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D009363:Neoplasm Proteins; C064925:gadodiamide; D019786:Gadolinium DTPA