title: Proton MR spectroscopy in predicting the increase of perfusion MR imaging for WHO grade II gliomas.
abstract: OBJECTIVE
  To investigate the correlation between the metabolite ratios obtained from proton magnetic resonance (MR) spectroscopy and those obtained from MR perfusion parameters (relative cerebral blood volume [rCBV]) in a cohort of low-grade glioma (LGG).
  
  
  METHODS
  Patients underwent prospectively conventional MR, proton magnetic resonance spectroscopy ((1) HMRS), and perfusion-weighted images (PWI). Statistical analyses were performed to determine the correlative and independent predictive factors of rCBVmax and the metabolite ratio thresholds with optimum sensitivity and specificity.
  
  
  RESULTS
  Thirty-one patients were included in this study. Linear correlations were observed between the metabolic ratios (lactate [Lac]/creatine [Cr], choline [Cho]/N-acetyl-aspartate [NAA], free-lipids/Cr) and rCBVmax (P < 0.05). These metabolic ratios were determined to be independent predictive factors of rCBVmax (P = 0.027, 0.011 and 0.032, respectively). According to the receiver operating characteristic curves, the cutoff values of the metabolic ratios to discriminate between the two populations of rCBVmax (<1.7 versus = 1.7) were 1.72, 1.54, and 1.40, respectively, with a sensitivity = 75% and a specificity >95% for Lac/Cr.
  
  
  CONCLUSIONS
  This study demonstrated consistent correlations between the data from (1) HMRS and PWI. The Lac/Cr ratio predicts regional hemodynamic changes, which are themselves a useful biomarker of clinical prognosis in patients with LGG. As such, this ratio may provide a new parameter for making improved clinical decisions.
authors: Department of Neuroradiology, Pitié-Sapêtrière Hospital, Paris, France. remy.guillevin@psl.aphp.fr
authors: Remy
authors: R
authors: Guillevin
authors: Carole
authors: C
authors: Menuel
authors: Lucas
authors: L
authors: Abud
authors: Robert
authors: R
authors: Costalat
authors: Laurent
authors: L
authors: Capelle
authors: Khê
authors: K
authors: Hoang-Xuan
authors: Christophe
authors: C
authors: Habas
authors: Jacques
authors: J
authors: Chiras
authors: Jean-Noel
authors: JN
authors: Vallée
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D005910:Glioma / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D060787:Neoplasm Grading; D009942:Organometallic Compounds; D011446:Prospective Studies; D011522:Protons; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014944:World Health Organization
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D011522:Protons; D008536:Meglumine; C072417:gadoterate meglumine