title: Preoperative grading of supratentorial gliomas using high or standard b-value diffusion-weighted MR imaging at 3T.
abstract: OBJECTIVE
  The goal of this study was to compare diffusion-weighted magnetic resonance imaging (DW-MRI) using high b-value (b=3000s/mm2) to DW-MRI using standard b-value (b=1000s/mm2) in the preoperative grading of supratentorial gliomas.
  
  
  METHODS
  Fifty-three patients with glioma had brain DW-MRI at 3T using two different b-values (b=1000s/mm2and b=3000s/mm2). There were 35 men and 18 women with a mean age of 40.5±17.1 years (range: 18-79 years). Mean, minimum, maximum, and range of apparent diffusion coefficient (ADC) values for solid tumor ROIs (ADCmean, ADCmin, ADCmax, and ADCdiff), and the normalized ADC (ADCratio) were calculated. A Kruskal-Wallis statistic with Bonferroni correction for multiple comparisons was applied to detect significant ADC parameter differences between tumor grades by including or excluding 19 patients with an oligodendroglioma. Receiver operating characteristic curve analysis was conducted to define appropriate cutoff values for grading gliomas.
  
  
  RESULTS
  No differences in ADC derived parameters were found between grade II and grade III gliomas. Mean ADC values using standard b-value were 1.17±0.27×10-3mm2/s [range: 0.63-1.61], 1.05±0.22×10-3mm2/s [range: 0.73-1.33], and 0.86±0.23×10-3mm2/s [range: 0.52-1.46] for grades II, III and IV gliomas, respectively. Using high b-value, mean ADC values were 0.89±0.24×10-3mm2/s [range: 0.42-1.25], 0.82±0.20×10-3mm2/s [range: 0.56-1.10], and 0.59±0.17×10-3mm2/s [range: 0.40-1.01] for grades II, III and IV gliomas, respectively. ADCmean, ADCratio, ADCmax, and ADCminwere different between grade II and grade IV gliomas at both standard and high b-values. Differences in ADCmean, ADCmax, and ADCdiffwere found between grade III and grade IV only using high b-value.
  
  
  CONCLUSIONS
  ADC parameters derived from DW-MRI using a high b-value allows a better differential diagnosis of gliomas, especially for differentiating grades III and IV, than those derived from DW-MRI using a standard b-value.
authors.affiliation: Bahçeşehir University, Department of Radiology, Medical Park Göztepe Hospital, Merdivenköy, Kadıköy, 34000 İstanbul, Turkey. Electronic address: mmutlucihan@hotmail.com.
authors.forename: M M
authors.initials: MM
authors.lastname: Cihangiroglu
authors.affiliation: Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Ozturk-Isik
authors.affiliation: Department of Radiology, Yeditepe University Hospital, Istanbul, Turkey.
authors.forename: Z
authors.initials: Z
authors.lastname: Firat
authors.affiliation: Department of Radiology, Istanbul Education and Research Hospital, Istanbul, Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Kilickesmez
authors.affiliation: Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey; CorTechs Labs, Inc, San Diego, CA, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Ulug
authors.affiliation: Department of Neurosurgery, Yeditepe University Hospital, Istanbul, Turkey.
authors.forename: U
authors.initials: U
authors.lastname: Ture
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011300:Preoperative Care; D055815:Young Adult
keywords: Diffusion-weighted MR imaging; Glioma; High b-value; Normalized apparent diffusion coefficient (ADC); Tumor grading