title: Optimized preload leakage-correction methods to improve the diagnostic accuracy of dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in posttreatment gliomas.
abstract: OBJECTIVE
  Relative cerebral blood volume (rCBV) accuracy can vary substantially depending on the dynamic susceptibility-weighted contrast-enhanced (DSC) acquisition and postprocessing methods, due to blood-brain barrier disruption and resulting T1-weighted leakage and T2- and/or T2*-weighted imaging (T2/T2*WI) residual effects. We set out to determine optimal DSC conditions that address these errors and maximize rCBV accuracy in differentiating posttreatment radiation effect (PTRE) and tumor.
  
  
  METHODS
  We recruited patients with previously treated high-grade gliomas undergoing image-guided re-resection of recurrent contrast-enhancing MR imaging lesions. Thirty-six surgical tissue samples were collected from 11 subjects. Preoperative 3T DSC used 6 sequential evenly timed acquisitions, each by using a 0.05-mmol/kg gadodiamide bolus. Preload dosing (PLD) and baseline subtraction (BLS) techniques corrected T1-weighted leakage and T2/T2*WI residual effects, respectively. PLD amount and incubation time increased with each sequential acquisition. Corresponding tissue specimen stereotactic locations were coregistered to DSC to measure localized rCBV under varying PLD amounts, incubation times, and the presence of BLS. rCBV thresholds were determined to maximize test accuracy (average of sensitivity and specificity) in distinguishing tumor (n = 21) and PTRE (n = 15) samples under the varying conditions. Receiver operator characteristic (ROC) areas under the curve (AUCs) were statistically compared.
  
  
  RESULTS
  The protocol that combined PLD (0.1-mmol/kg amount, 6-minute incubation time) and BLS correction methods maximized test AUC (0.99) and accuracy (95.2%) compared with uncorrected rCBV AUC (0.85) and accuracy (81.0%) measured without PLD and BLS (P = .01).
  
  
  CONCLUSIONS
  Combining PLD and BLS correction methods for T1-weighted and T2/T2*WI errors, respectively, enables highly accurate differentiation of PTRE and tumor growth.
authors.affiliation: Department of Radiology, Mayo Clinic, Phoenix/Scottsdale, Arizona 85259, USA. Hu.Leland@Mayo.Edu
authors.forename: L S
authors.initials: LS
authors.lastname: Hu
authors.forename: L C
authors.initials: LC
authors.lastname: Baxter
authors.forename: D S
authors.initials: DS
authors.lastname: Pinnaduwage
authors.forename: T L
authors.initials: TL
authors.lastname: Paine
authors.forename: J P
authors.initials: JP
authors.lastname: Karis
authors.forename: B G
authors.initials: BG
authors.lastname: Feuerstein
authors.forename: K M
authors.initials: KM
authors.lastname: Schmainda
authors.forename: A C
authors.initials: AC
authors.lastname: Dueck
authors.forename: J
authors.initials: J
authors.lastname: Debbins
authors.forename: K A
authors.initials: KA
authors.lastname: Smith
authors.forename: P
authors.initials: P
authors.lastname: Nakaji
authors.forename: J M
authors.initials: JM
authors.lastname: Eschbacher
authors.forename: S W
authors.initials: SW
authors.lastname: Coons
authors.forename: J E
authors.initials: JE
authors.lastname: Heiserman
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D005260:Female; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results