title: Quantitative diffusion-weighted and dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging analysis of T2 hypointense lesion components in pediatric diffuse intrinsic pontine glioma.
abstract: OBJECTIVE
  Focal anaplasia characterized by T2 hypointensity, signal-intensity enhancement on postcontrast T1-weighted MR imaging and restricted water diffusion has been reported in a patient with juvenile pilocytic astrocytoma. We identified T2(HOF) with these MR imaging characteristics in children with DIPG and hypothesized that these represent areas of focal anaplasia; and may, therefore, have increased perfusion properties and should be characterized by increased perfusion. Thus, we used DSC to investigate our hypothesis.
  
  
  METHODS
  We retrospectively reviewed the baseline MR imaging scans of 86 patients (49 girls, 37 boys; median age, 6.1 years; range, 1.1-17.6 years) treated for DIPG at our hospital (2004-2009). T2(HOF) with the described MR imaging characteristics was identified in 10 patients. We used a region of interest-based approach to compare the ADC, FA, rCBV, rCBF, and rMTT of T2(HOF) with those of the typical T2(HRT).
  
  
  RESULTS
  The ADC of T2(HOF) with the specified MR imaging characteristics was significantly lower than that of T2(HRT) (range, 0.71-1.95 μm(2)/ms versus 1.36-2.13 μm(2)/ms; P < .01); and the FA (range, 0.12-0.34 versus 0.07-0.24; P = .03) and rCBV (range, 0.4-2.62 versus 0.23-1.57; P = .01) values of T2(HOF)s were significantly higher.
  
  
  CONCLUSIONS
  Our data suggest that T2(HOF) in DIPG may represent areas of focal anaplasia and underline the importance of regional, rather than global, tumor-field analysis. T2(HOF) may be the ideal target when stereotactic biopsy of tumors that present with an inhomogeneous T2 signal intensity is considered.
authors.affiliation: Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105-2794, USA.
authors.forename: U
authors.initials: U
authors.lastname: Löbel
authors.forename: J
authors.initials: J
authors.lastname: Sedlacik
authors.forename: W E
authors.initials: WE
authors.lastname: Reddick
authors.forename: M
authors.initials: M
authors.lastname: Kocak
authors.forename: Q
authors.initials: Q
authors.lastname: Ji
authors.forename: A
authors.initials: A
authors.lastname: Broniscer
authors.forename: C M
authors.initials: CM
authors.lastname: Hillenbrand
authors.forename: Z
authors.initials: Z
authors.lastname: Patay
mesh_terms: D000293:Adolescent; D001706:Biopsy; D020295:Brain Stem Neoplasms / Q000098:blood supply / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000098:blood supply / Q000473:pathology*; D006801:Humans; D007223:Infant; D008297:Male; D009336:Necrosis; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media