title: Diagnostic accuracy of dynamic contrast-enhanced MR imaging using a phase-derived vascular input function in the preoperative grading of gliomas.
abstract: OBJECTIVE
  The accuracy of tumor plasma volume and K(trans) estimates obtained with DCE MR imaging may have inaccuracies introduced by a poor estimation of the VIF. In this study, we evaluated the diagnostic accuracy of a novel technique by using a phase-derived VIF and "bookend" T1 measurements in the preoperative grading of patients with suspected gliomas.
  
  
  METHODS
  This prospective study included 46 patients with a new pathologically confirmed diagnosis of glioma. Both magnitude and phase images were acquired during DCE MR imaging for estimates of K(trans)_φ and V(p_)φ (calculated from a phase-derived VIF and bookend T1 measurements) as well as K(trans)_SI and V(p_)SI (calculated from a magnitude-derived VIF without T1 measurements).
  
  
  RESULTS
  Median K(trans)_φ values were 0.0041 minutes(-1) (95 CI, 0.00062-0.033), 0.031 minutes(-1) (0.011-0.150), and 0.088 minutes(-1) (0.069-0.110) for grade II, III, and IV gliomas, respectively (P ≤ .05 for each). Median V(p_)φ values were 0.64 mL/100 g (0.06-1.40), 0.98 mL/100 g (0.34-2.20), and 2.16 mL/100 g (1.8-3.1) with P = .15 between grade II and III gliomas and P = .015 between grade III and IV gliomas. In differentiating low-grade from high-grade gliomas, AUCs for K(trans)_φ, V(p_φ), K(trans)_SI, and V(p_)SI were 0.87 (0.73-1), 0.84 (0.69-0.98), 0.81 (0.59-1), and 0.84 (0.66-0.91). The differences between the AUCs were not statistically significant.
  
  
  CONCLUSIONS
  K(trans)_φ and V(p_)φ are parameters that can help in differentiating low-grade from high-grade gliomas.
authors.affiliation: Department of Radiology, The Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada. thnguyen@ottawahospital.on.ca
authors.forename: T B
authors.initials: TB
authors.lastname: Nguyen
authors.forename: G O
authors.initials: GO
authors.lastname: Cron
authors.forename: J F
authors.initials: JF
authors.lastname: Mercier
authors.forename: C
authors.initials: C
authors.lastname: Foottit
authors.forename: C H
authors.initials: CH
authors.lastname: Torres
authors.forename: S
authors.initials: S
authors.lastname: Chakraborty
authors.forename: J
authors.initials: J
authors.lastname: Woulfe
authors.forename: G H
authors.initials: GH
authors.lastname: Jansen
authors.forename: J M
authors.initials: JM
authors.lastname: Caudrelier
authors.forename: J
authors.initials: J
authors.lastname: Sinclair
authors.forename: M J
authors.initials: MJ
authors.lastname: Hogan
authors.forename: R E
authors.initials: RE
authors.lastname: Thornhill
authors.forename: I G
authors.initials: IG
authors.lastname: Cameron
mesh_terms: D019540:Area Under Curve; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media; D019786:Gadolinium DTPA; D005910:Glioma / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA