title: Dynamic contrast-enhanced T2*-weighted MR imaging of gliomatosis cerebri.
abstract: OBJECTIVE
  MR imaging characteristics of gliomatosis cerebri reiterate the diffuse nature of this tumor but are nonspecific and thus may pose a diagnostic challenge. Because perfusion MR imaging can provide a physiologic map of the microcirculation, we compared the measured relative cerebral blood volume (rCBV) at perfusion imaging with histopathologic findings in gliomatosis cerebri. MR spectroscopic findings were also reviewed.
  
  
  METHODS
  Retrospective analysis was performed of conventional and perfusion MR images from seven patients with proved gliomatosis cerebri. The conventional MR images were evaluated for the presence or absence of contrast enhancement, necrosis, and extent of T2-weighted signal intensity abnormality. Dynamic contrast-enhanced T2*-weighted gradient-echo echo-planar images were acquired during the first pass of a bolus injection of gadopentetate dimeglumine. The rCBV was calculated by using nondiffusible tracer kinetics and expressed relative to normal-appearing white matter. Pathologic findings were reviewed in all patients and compared with the MR perfusion data. Multivoxel 2D chemical shift imaging proton MR spectroscopic data were available for three patients and single-voxel data for one patient.
  
  
  RESULTS
  Conventional MR images showed diffuse abnormality in all cases and absence of contrast enhancement in all but one case. Average rCBV range was 0.75-1.26 (mean, 1.02 +/- 0.42 [SD]). MR spectroscopic data revealed spectra consistent with presence of tumoral disease. Histopathologic review showed absence of vascular hyperplasia in all specimens.
  
  
  CONCLUSIONS
  The low MR rCBV measurements of gliomatosis cerebri are in concordance with the lack of vascular hyperplasia found at histopathologic examination; thus, perfusion MR imaging provides useful adjunctive information that is not available from conventional MR imaging techniques.
authors.affiliation: Department of Radiology, New York University Medical Center, NY, USA.
authors.forename: Stanley
authors.initials: S
authors.lastname: Yang
authors.forename: Stephan
authors.initials: S
authors.lastname: Wetzel
authors.forename: M
authors.initials: M
authors.lastname: Law
authors.forename: D
authors.initials: D
authors.lastname: Zagzag
authors.forename: Soonmee
authors.initials: S
authors.lastname: Cha
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001810:Blood Volume / Q000502:physiology*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018302:Neoplasms, Neuroepithelial / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA