title: "Tumoral pseudoblush" identified within gliomas at high-spatial-resolution ultrahigh-field-strength gradient-echo MR imaging corresponds to microvascularity at stereotactic biopsy.
abstract: OBJECTIVE
  To use directed biopsy sampling to determine whether microvascular assessment within gliomas, by means of ultrahigh-field-strength high-spatial-resolution gradient-echo (GRE) magnetic resonance (MR) imaging at 8 T, correlates with histopathologic assessment of microvascularity.
  
  
  METHODS
  The study was institutional review board approved and HIPAA compliant. Informed consent was obtained. Thirty-five subjects with gliomas underwent 8-T and 80-cm MR imaging by using a GRE sequence (repetition time, 600-750 msec; echo time, 10 msec; in-plane resolution, 196 mm). Haphazardly arranged serpentine low-signal-intensity structures, often associated with areas of low signal intensity within the tumor bed ("tumoral pseudoblush") at MR imaging, were presumed to be related to tumoral microvascularity. Microvessel density (MVD) and microvessel size (MVS) ranked with a semiquantitative three-tier scale (high, medium, and low) relative to cortical penetrating veins were assessed from regions of interest identified at MR imaging and were compared with a similar assessment of stereotactic biopsy specimens by using Kendall τb. Tumor grade (high vs low) was compared with ultrahigh-field-strength high-resolution GRE MR analysis by using Pearson χ2. Discrepancies between 8-T and histopathologic assessment were identified and analyzed.
  
  
  RESULTS
  Ultrahigh-field-strength high-resolution GRE MR imaging and histopathologic assessment concurred for MVS (P<.0001) and MVD (P<.0001). World Health Organization classification tumor grade was associated with number (P<.0005) and size (P<.0005) of foci of microvascularity within the tumor bed at 8-T MR imaging. Radiation-induced microvessel hyalinosis mimicked tumor microvascularity at 8-T MR imaging. Potential confounders could result from radiofrequency inhomogeneity and displaced normal microvasculature.
  
  
  CONCLUSIONS
  Microvascularity identified as a tumoral pseudoblush at ultrahigh-field-strength high-resolution GRE MR imaging without contrast material shows promise as a marker for increased tumoral microvascularity.
authors.affiliation: Department of Radiology, University of Chicago Medical Center, 5841 S Maryland Ave, MC2026, Chicago, IL 60601, USA. gchristoforidis@radiology.bsd.uchicago.edu
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Christoforidis
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Amir
authors.initials: A
authors.lastname: Abduljalil
authors.forename: Abhik R
authors.initials: AR
authors.lastname: Chaudhury
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Newton
authors.forename: John M
authors.initials: JM
authors.lastname: McGregor
authors.forename: Clara R
authors.initials: CR
authors.lastname: Epstein
authors.forename: William T C
authors.initials: WT
authors.lastname: Yuh
authors.forename: Sydeaka
authors.initials: S
authors.lastname: Watson
authors.forename: Pierre-Marie L
authors.initials: PM
authors.lastname: Robitaille
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001932:Brain Neoplasms / Q000175:diagnosis*; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000175:diagnosis*; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA