title: Quantification of blood flow in brain tumors: comparison of arterial spin labeling and dynamic susceptibility-weighted contrast-enhanced MR imaging.
abstract: OBJECTIVE
  To implement an arterial spin labeling technique that is feasible in routine examinations and to test the method and compare it with dynamic susceptibility-weighted contrast material-enhanced magnetic resonance (MR) imaging for evaluation of tumor blood flow (TBF) in patients with brain tumors.
  
  
  METHODS
  Thirty-six patients with histologically proven brain tumors were examined at 1.5 T. A second version of quantitative imaging of perfusion by using a single subtraction with addition of thin-section periodic saturation after inversion and a time delay (Q2TIPS) technique of pulsed arterial spin labeling in the multisection mode was implemented. After arterial spin labeling, a combined T2- and T2*-weighted first-pass bolus perfusion study (gadopentetate dimeglumine, 0.2 mmol/kg) was performed by using a double-echo echo-planar imaging sequence. In regions of interest, maps of absolute and relative cerebral blood flow were computed and analyzed with arterial spin labeling and dynamic susceptibility-weighted contrast-enhanced MR imaging, respectively.
  
  
  RESULTS
  Both techniques yielded the highest perfusion values in imaging of glioblastomas and the lowest values in imaging of two low-grade gliomas that both showed strong gadopentetate dimeglumine enhancement. There was a close linear correlation between dynamic susceptibility-weighted contrast-enhanced MR imaging and arterial spin labeling in the tumor region of interest (linear regression coefficient, R = 0.83; P <.005). Blood flow is underestimated with arterial spin labeling at low flow rates. High- and low-grade gliomas can be distinguished at the same level of significance with both methods. Absolute TBF is less important for tumor grading than is the ratio of TBF to age-dependent mean brain perfusion.
  
  
  CONCLUSIONS
  Arterial spin labeling is a suitable method for assessment of microvascular perfusion and allows distinction between high- and low-grade gliomas.
authors.affiliation: Department of Neuroradiology, Charité Medical School, Humboldt University of Berlin, Schumannstrasse 20-21, D-10098 Berlin, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Warmuth
authors.forename: Matthias
authors.initials: M
authors.lastname: Gunther
authors.forename: Claus
authors.initials: C
authors.lastname: Zimmer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000098:blood supply* / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000098:blood supply* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D010477:Perfusion; D013113:Spin Labels; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D013113:Spin Labels; D019786:Gadolinium DTPA