title: Assesment of perfusion in glial tumors with arterial spin labeling; comparison with dynamic susceptibility contrast method.
abstract: OBJECTIVE
  Arterial spin labeling perfusion imaging (ASL-PI) is a non-invasive perfusion imaging method that can be used for evaluation and quantification of cerebral blood flow (CBF). Aim of our study was to evaluating the efficiency of ASL in histopathological grade estimation of glial tumors and comparing findings with dynamic susceptibility contrast perfusion imaging (DSC-PI) method.
  
  
  METHODS
  This study involved 33 patients (20 high-grade and 13 low-grade gliomas). Multiphase multislice pulsed ASL MRI sequence and a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence were acquired for all the patients. For each patient, perfusion relative signal intensity (rSI), CBF and relative CBF (rCBF) on ASL-PI and relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values on DSC-PI were determined. The relative signal intensity of each tumor was determined as the maximal SI within the tumor divided by SI within symetric region in the contralateral hemisphere on ASL-PI. rCBV and rCBF were calculated by deconvolution of an arterial input function. Relative values of the lesions were obtained by dividing the values to the normal appearing symmetric region on the contralateral hemisphere. For statistical analysis, Mann-Whitney ranksum test was carried out. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBF-ASL, rSI-ASL, rCBV and rCBF ratios and grade of gliomas. Their cut-off values permitting best discrimination was calculated. The correlation between rCBV, rCBF, rSI-ASL and rCBF-ASL and glioma grade was assessed using Spearman correlation analysis.
  
  
  RESULTS
  There was a statistically significant difference between low and high-grade tumors for all parameters. Correlation analyses revealed significant positive correlations between rCBV and rCBF-ASL (r=0.81, p<0.001). However correlation between rCBF and rCBF-ASL was weaker (r=0.64, p<0.001).
  
  
  CONCLUSIONS
  Arterial spin labeling is an employable imaging technique for evaluating tumor perfusion non-invasively and may be useful in differentiating high and low grade gliomas.
authors.affiliation: Department of Radiology, Uludag University Medical School, Bursa, Turkey. Electronic address: hcebeci16@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Cebeci
authors.affiliation: Department of Radiology, Uludag University Medical School, Bursa, Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Aydin
authors.affiliation: Department of Biomedical Engineering, Yeditepe University, Istanbul, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Ozturk-Isik
authors.affiliation: Department of Biomedical Engineering, Yeditepe University, Istanbul, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Gumus
authors.affiliation: Department of Radiology, Kanuni Sultan Suleyman Educational and Research Hospital, Istanbul, Turkey.
authors.forename: F
authors.initials: F
authors.lastname: Inecikli
authors.affiliation: Department of Neurosurgery, Uludag University Medical School, Bursa, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Bekar
authors.affiliation: Department of Neurosurgery, Uludag University Medical School, Bursa, Turkey.
authors.forename: H
authors.initials: H
authors.lastname: Kocaeli
authors.affiliation: Department of Radiology, Uludag University Medical School, Bursa, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Hakyemez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001810:Blood Volume; D001932:Brain Neoplasms / Q000098:blood supply* / Q000473:pathology*; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000098:blood supply* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D003287:Contrast Media; D013113:Spin Labels; C064925:gadodiamide; D019786:Gadolinium DTPA
keywords: Arterial spin labeling; Dynamic susceptibility contrast perfusion imaging; Glioma