title: High- and low-grade glioma differentiation: the role of percentage signal recovery evaluation in MR dynamic susceptibility contrast imaging.
abstract: OBJECTIVE
  Evaluation of cerebral blood volume (CBV) with magnetic resonance (MR) imaging can differentiate low-grade from high-grade gliomas. The percentage of signal recovery (PSR) in the venous phase of perfusion curves is inversely proportional to blood-brain barrier (BBB) permeability. Since even BBB permeability relates to glioma malignancy grade, we carried out a comparative evaluation between CBV and PSR to characterise cerebral gliomas.
  
  
  METHODS
  Forty-nine patients with cerebral gliomas were studied with MR perfusion imaging. In all tumours, both maximum CBV and minimum PSR were calculated. The difference between the CBV and PSR mean values among the low-grade and high-grade gliomas was assessed using statistical methods. We also examined whether there was an additional difference between low-grade and grade III gliomas. Finally, CBV and PSR diagnostic sensitivity and specificity in identifying low-grade gliomas compared to all gliomas and low-grade gliomas compared to all gliomas excluding glioblastomas was assessed.
  
  
  RESULTS
  A significant difference between low-grade and high-grade gliomas with both CBV and PSR was demonstrated. Conversely, there was a significant difference between low-grade and grade III gliomas only with PSR, while CBV did not show significant difference. Finally, superior sensitivity and specificity of PSR compared to CBV in identifying low-grade gliomas was demonstrated both compared to all gliomas and all gliomas excluding glioblastomas.
  
  
  CONCLUSIONS
  The PSR evaluation proved better than CBV for determining the grade of brain and is therefore a useful tool to be considered in the MR evaluation of gliomas.
authors.affiliation: Neuroradiology Unit, S. Maria Hospital, Terni, Italy. aprileita@libero.it.
authors.forename: Italo
authors.initials: I
authors.lastname: Aprile
authors.affiliation: Neuroradiology Unit, S. Maria Hospital, Terni, Italy. giorgiagiovannelli@libero.it.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Giovannelli
authors.affiliation: Neuroradiology Unit, S. Maria Hospital, Terni, Italy. pfiaschini@gmail.com.
authors.forename: Paola
authors.initials: P
authors.lastname: Fiaschini
authors.affiliation: Radiotherapy Unit, S. Maria Hospital, Terni, Italy. marco.muti@tin.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Muti
authors.affiliation: Neuroradiology Unit, S. Maria Hospital, Terni, Italy. kouleridou@libero.it.
authors.forename: Anna
authors.initials: A
authors.lastname: Kouleridou
authors.affiliation: Neuroradiology Unit, S. Maria Hospital, Terni, Italy. neviacaputo@libero.it.
authors.forename: Nevia
authors.initials: N
authors.lastname: Caputo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume; D001932:Brain Neoplasms / Q000473:pathology*; D002560:Cerebrovascular Circulation; D003937:Diagnosis, Differential; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D012189:Retrospective Studies; D055815:Young Adult
keywords: Glioma; Magnetic resonance; Perfusion imaging; Permeability