title: Definition of K(trans) and FA thresholds for better assessment of experimental glioma using high-field MRI: a feasibility study.
abstract: OBJECTIVE
  To define K(trans) and fractional anisotropy (FA) thresholds in correlation to histology for improved magnetic resonance imaging (MRI) tumor assessment in an animal model of brain glioma.
  
  
  METHODS
  Twelve rats underwent 4.7 T MRI at day 10 after tumor implantation. Anatomical scans (T2, T1 at 8 min after double dose contrast application) as well as dynamic contrast-enhanced (DCE) imaging with calculation of K(trans) and diffusion tensor imaging (DTI) with calculation of FA were performed. T2- and T1-derived tumor volumes were calculated and thresholds for K(trans) and FA were defined for best MRI tumor assessment correlated to histology.
  
  
  RESULTS
  Tumor volumes were 159 ± 14 mm(3) (histology), 126 ± 26 mm(3) (T1 with contrast, r=0.76), and 153 ± 12 mm(3) (T2, r=0.84), respectively. K(trans)- and FA-derived tumor volumes were 160 ± 16 mm(3) (for K(trans ≥ 0.04 min(-1), r=0.94), and 159 ± 14 mm(3) (for FA £0.14, r=0.96), respectively.
  
  
  CONCLUSIONS
  DCE-MRI and DTI with calculation of K(trans) and FA maps allow very precise brain glioma assessment comparable to histology if established thresholds for the given tumor model are used.
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054, Erlangen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Engelhorn
authors.forename: M A
authors.initials: MA
authors.lastname: Schwarz
authors.forename: A
authors.initials: A
authors.lastname: Hess
authors.forename: L
authors.initials: L
authors.lastname: Budinsky
authors.forename: P
authors.initials: P
authors.lastname: Pitann
authors.forename: I
authors.initials: I
authors.lastname: Eyüpoglu
authors.forename: A
authors.initials: A
authors.lastname: Doerfler
mesh_terms: D000465:Algorithms; D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005240:Feasibility Studies; D005910:Glioma / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047368:Tumor Burden