title: Glial neoplasms: dynamic contrast-enhanced T2*-weighted MR imaging.
abstract: OBJECTIVE
  To evaluate the role of T2*-weighted echo-planar perfusion imaging by using a first-pass gadopentetate dimeglumine technique to determine the association of magnetic resonance (MR) imaging-derived cerebral blood volume (CBV) maps with histopathologic grading of astrocytomas and to improve the accuracy of targeting of stereotactic biopsy.
  
  
  METHODS
  MR imaging was performed in 29 patients by using a first-pass gadopentetate dimeglumine T2*-weighted echo-planar perfusion sequence followed by conventional imaging. The perfusion data were processed to obtain a color map of relative regional CBV. This information formed the basis for targeting the stereotactic biopsy. Relative CBV values were computed with a nondiffusible tracer model. The relative CBV of lesions was expressed as a percentage of the relative CBV of normal white matter. The maximum relative CBV of each lesion was correlated with the histopathologic grading of astrocytomas obtained from samples from stereotactic biopsy or volumetric resection.
  
  
  RESULTS
  The maximum relative CBV in high-grade astrocytomas (n = 26) varied from 1.73 to 13.7, with a mean of 5.07 +/- 2.79 (+/- SD), and in the low-grade cohort (n = 3) varied from 0.92 to 2.19, with a mean of 1.44 +/- 0.68. This difference in relative CBV was statistically significant (P < .001; Student t test).
  
  
  CONCLUSIONS
  Echo-planar perfusion imaging is useful in the preoperative assessment of tumor grade and in providing diagnostic information not available with conventional MR imaging. The areas of perfusion abnormality are invaluable in the precise targeting of the stereotactic biopsy.
authors.affiliation: Department of Radiology, Kaplan Comprehensive Cancer Center, New York University Medical Center, NY 10016, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Knopp
authors.forename: S
authors.initials: S
authors.lastname: Cha
authors.forename: G
authors.initials: G
authors.lastname: Johnson
authors.forename: A
authors.initials: A
authors.lastname: Mazumdar
authors.forename: J G
authors.initials: JG
authors.lastname: Golfinos
authors.forename: D
authors.initials: D
authors.lastname: Zagzag
authors.forename: D C
authors.initials: DC
authors.lastname: Miller
authors.forename: P J
authors.initials: PJ
authors.lastname: Kelly
authors.forename: I I
authors.initials: II
authors.lastname: Kricheff
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001254:Astrocytoma / Q000175:diagnosis* / Q000473:pathology; D001706:Biopsy; D001810:Blood Volume; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D017352:Echo-Planar Imaging; D005260:Female; D019786:Gadolinium DTPA; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013238:Stereotaxic Techniques
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA