title: Can the apparent diffusion coefficient be used as a noninvasive parameter to distinguish tumor tissue from peritumoral tissue in cerebral gliomas?
abstract: OBJECTIVE
  To determine whether the apparent diffusion coefficient (ADC) can be used to distinguish between tumor tissue and peritumoral brain tissue in cerebral gliomas.
  
  
  METHODS
  Twenty-two patients with 44 biopsies were enrolled in this study. ADC maps calculated from a diffusion-weighted (DW) multislice EPI sequence were coregistered with conventional MR images. Neuronavigated biopsies and intraoperative markers were used for correlation with the histologic specimens. ADC values and lesion-to-brain ratios of the different sequences were calculated and compared for tumor tissue and peritumoral brain tissue. A logistic regression analysis was performed to determine the diagnostic value of the ADC maps.
  
  
  RESULTS
  The ADC values and ratios demonstrated a large overlap between tumor tissue and peritumoral tissue. Group comparisons revealed a significantly (P=0.03) lower ADC ratio in tumor tissue (mean=1.28 +/- 0.39) compared to peritumoral tissue (mean=1.48 +/- 0.30), whereas the absolute ADC values did not differ significantly. In the logistic regression analysis, the lesion-to-brain ratio of the gadolinium (Gd)-enhanced T1-weighted sequence was the most valuable predictor of the presence of tumor tissue. The ADC value and ratio were not identified as significant predictors.
  
  
  CONCLUSIONS
  The ADC is not helpful for distinguishing tumor tissue from peritumoral brain tissue in gliomas.
authors.affiliation: Clinic for Nuclear Medicine (KME), Research Center Jülich, Jülich, Germany. pauleit@web.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Pauleit
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Langen
authors.forename: Frank
authors.initials: F
authors.lastname: Floeth
authors.forename: Hubertus
authors.initials: H
authors.lastname: Hautzel
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Riemenschneider
authors.forename: Guido
authors.initials: G
authors.lastname: Reifenberger
authors.forename: N Jon
authors.initials: NJ
authors.lastname: Shah
authors.forename: Hans-Wilhelm
authors.initials: HW
authors.lastname: Müller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000175:diagnosis*; D001706:Biopsy / Q000379:methods; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004487:Edema / Q000175:diagnosis; D005260:Female; D019786:Gadolinium DTPA; D005909:Glioblastoma / Q000175:diagnosis*; D005910:Glioma / Q000175:diagnosis*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000175:diagnosis*; D012044:Regression Analysis
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA