title: Differentiation of low-grade oligodendrogliomas from low-grade astrocytomas by using quantitative blood-volume measurements derived from dynamic susceptibility contrast-enhanced MR imaging.
abstract: OBJECTIVE
  Histopathologic evaluation remains the reference standard for diagnosis of glioma and classification of histologic subtypes, but is challenged by subjective criteria, tissue sampling error, and lack of specific tumor markers. Anatomic imaging is essential for surgical planning of gliomas but is limited by its nonspecificity and its inability to depict beyond morphologic aberrations. The purpose of our study was to investigate dynamic susceptibility contrast-enhanced (DSC) MR imaging characteristics of the two most common subtypes of low-grade infiltrating glioma: astrocytoma and oligodendroglioma. We hypothesized that tumor blood-volume measurements, derived from DSC MR imaging, would help differentiate the two on the basis of differences in tumor vascularity.
  
  
  METHODS
  We studied 25 consecutive patients with treatment-naive, histopathologically confirmed World Health Organization grade II astrocytoma (n = 11) or oligodendroglioma (n = 14). All patients underwent anatomic and DSC MR imaging immediately before surgical resection. Histologic confirmation was obtained in all patients. Anatomic MR images were analyzed for morphologic features, and DSC MR data were processed to yield quantitative cerebral blood volume (CBV) measurements.
  
  
  RESULTS
  The maximum relative CBV (rCBV(max)) in tumor ranged from 0.48 to 1.34 (0.92 +/- 0.27, median +/- SD) in astrocytomas and from 1.29 to 9.24 (3.68 +/- 2.39) in oligodendrogliomas. The difference in median rCBV(max) between the two tumor types was significant (P < .0001).
  
  
  CONCLUSIONS
  The tumor rCBV(max) measurements derived from DSC MR imaging were significantly higher in low-grade oligodendrogliomas than in astrocytomas. Our findings suggest that tumor rCBV(max) derived from DSC MR imaging can be used to distinguish between the two low-grade gliomas.
authors.affiliation: Department of Radiology, University of California-San Francisco, UCSF Medical Center, 505 Parnassus Avenue, San Francisco, CA 94143-0628, USA.
authors.forename: Soonmee
authors.initials: S
authors.lastname: Cha
authors.forename: Tarik
authors.initials: T
authors.lastname: Tihan
authors.forename: Forrest
authors.initials: F
authors.lastname: Crawford
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Fischbein
authors.forename: Susan
authors.initials: S
authors.lastname: Chang
authors.forename: Andrew
authors.initials: A
authors.lastname: Bollen
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Nelson
authors.forename: Michael
authors.initials: M
authors.lastname: Prados
authors.forename: Mitchel S
authors.initials: MS
authors.lastname: Berger
authors.forename: William P
authors.initials: WP
authors.lastname: Dillon
mesh_terms: D000328:Adult; D000368:Aged; D001810:Blood Volume; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000473:pathology*
chemical_list: D003287:Contrast Media