title: Early versus late GD-DTPA MRI enhancement in experimental glioblastomas.
abstract: OBJECTIVE
  To compare early versus late enhancement in two glioblastoma models characterized by different infiltrative/edematous patterns.
  
  
  METHODS
  Three weeks after inoculation into nude mice of U87MG and U251 cells, T1-weighted images were acquired early (10.5 min), intermediate (21 min) and late (30.5 min) after a bolus injection of Gd-DTPA at 300 μ mol/kg dosage. EARLY(TH) and LATE(TH) were the corresponding volumes with an enhancement higher than a threshold TH, defined by the mean (μ) and standard deviation (σ) on a contralateral healthy area. ADD(TH) was the enhancing volume found in LATE(TH) but not in EARLY(TH). T2 imaging of both tumors was performed, and T2 mapping of U251.
  
  
  RESULTS
  In all tumors, LATE(TH) was significantly higher than EARLY(TH) for TH ranging from μ+σ to μ+5σ. The ADD(TH) /EARLY(TH) ratio was not significantly different when U251 and U87MG tumors were compared. In the U87MG tumors, some enhancement was observed outside the regularly demarcated T2-hyperintense area. In the U251 tumors, irregularly T2 demarcated, a large portion of ADD(μ+3σ) had normal T2 values. At histology, U251 showed a higher infiltrative pattern than U87MG.
  
  
  CONCLUSIONS
  In these models, the increase over time in the enhancing volume did not depend on the different infiltrative/edematous patterns and was not closely related with edema.
authors.affiliation: Department of Morphological-Biomedical Sciences, Section of Anatomy and Histology, University of Verona, Verona, Italy. paolofarace@anatomy.univr.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Farace
authors.forename: Stefano
authors.initials: S
authors.lastname: Tambalo
authors.forename: Silvia
authors.initials: S
authors.lastname: Fiorini
authors.forename: Flavia
authors.initials: F
authors.lastname: Merigo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Daducci
authors.forename: Elena
authors.initials: E
authors.lastname: Nicolato
authors.forename: Giamaica
authors.initials: G
authors.lastname: Conti
authors.forename: Anna
authors.initials: A
authors.lastname: Degrassi
authors.forename: Andrea
authors.initials: A
authors.lastname: Sbarbati
authors.forename: Pasquina
authors.initials: P
authors.lastname: Marzola
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology*; D045744:Cell Line, Tumor; D003287:Contrast Media / Q000494:pharmacology*; D004487:Edema; D019786:Gadolinium DTPA / Q000494:pharmacology*; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000473:pathology
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA