title: Dynamic susceptibility contrast perfusion weighted imaging in grading of nonenhancing astrocytomas.
abstract: OBJECTIVE
  To evaluate if the relative tumor blood volume (rTBV) using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) can aid in distinguishing low- from high-grade nonenhancing astrocytomas.
  
  
  METHODS
  Seventeen patients with histologically proven astrocytomas underwent MRI including DSC-MRI. Maximum TBV regions of interest were recorded from each neoplasm and normalized to contralateral normal white matter. Demographic features, diagnostic MRI findings including tumor volumes, and the normalized rTBV ratios were compared between low-grade (I and II, LGA, n = 6) and high-grade (III) astrocytomas (HGA, n = 11) using Mann-Whitney's U-test and receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  Maximum rTBV ratios were statistically higher for HGA (1.11 ± 0.13) than LGA (0.66 ± 0.17, P < 0.005) with the best cutoff threshold at 0.94 (sensitivity of 90.9%, specificity of 100%). Differences in mean age and tumor volume on fluid-attenuated inversion recovery (FLAIR) imaging between the two groups did not reach statistical difference (P = 0.22, 0.36).
  
  
  CONCLUSIONS
  The addition of DSC-MRI can aid in accurate grading of nonenhancing astrocytomas with high sensitivity and specificity.
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA. nmorita@clin.med.tokushima-u.ac.jp
authors.forename: Naomi
authors.initials: N
authors.lastname: Morita
authors.forename: Sumei
authors.initials: S
authors.lastname: Wang
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Chawla
authors.forename: Harish
authors.initials: H
authors.lastname: Poptani
authors.forename: Elias R
authors.initials: ER
authors.lastname: Melhem
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001254:Astrocytoma / Q000175:diagnosis* / Q000473:pathology*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D015233:Models, Statistical; D010477:Perfusion; D012372:ROC Curve; D012680:Sensitivity and Specificity