title: Short-echo time proton MR spectroscopy in the presence of gadolinium.
abstract: OBJECTIVE
  The purpose of this work was to quantify the impact of contrast agents on short-TE single-voxel 1H MR spectroscopy (MRS) diagnosis of recurrent brain tumors.
  
  
  METHODS
  Short-TE 1H MRS was performed in 49 patients with biopsy-proven brain tumors and 14 control subjects. Eight patients (nine paired exams) were examined before and after administration of Gd-DTPA (interval approximately 5-7 min).
  
  
  RESULTS
  Tumor spectra showed increased choline/creatine ratio (Cho/Cr; p < 0.009) and Cho concentrations (p < 0.02). Receiver operator characteristic for Cho/Cr = 0.93 differentiated 100% of tumors from control in the absence or presence of contrast agent. Repeated 1H MRS varied <3%. Cho T2 was significantly longer than Cr T2 (p < 0.02).
  
  
  CONCLUSIONS
  Proton MRS with TE of 30 ms may safely be used in combined contrast-enhanced MRI/MRS protocols. Further study is required with long-TE MRS because of the prolonged T2 of Cho.
authors.affiliation: Magnetic Resonance Spectroscopy Unit, Huntington Medical Research Institutes, Pasadena, CA 91105, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Lin
authors.forename: B D
authors.initials: BD
authors.lastname: Ross
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005682:Gadolinium; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011522:Protons; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D003287:Contrast Media; D011522:Protons; D005682:Gadolinium