title: Different signal intensities between intra- and extracranial components in jugular foramen meningioma: an enigma.
abstract: OBJECTIVE
  The purpose of this study was to evaluate retrospectively differences in MR signal intensity and contrast enhancement between intra- and extracranial components of jugular foramen meningioma (JFM).
  
  
  METHODS
  MR studies of eight patients who underwent surgery for histologically confirmed JFM were reviewed retrospectively. Signal intensity differences between intra- and extracranial components of all eight JFMs on axial T1-, T2-, and postcontrast T1-weighted images were evaluated visually. In six of the eight JFMs, quantitative signal intensity evaluations were also performed by using relative signal intensity ratios of the intra- and extracranial components of JFM to CNS tissue at the same level. Paired t tests were used to evaluate differences in relative signal intensity ratios in each JFM between intra- and extracranial components.
  
  
  RESULTS
  Both visual and quantitative signal intensity evaluations revealed that signal intensities of the intracranial component of JFM were significantly higher than those of the extracranial component on T1-, T2-, and postcontrast T1-weighted images. Results of relative signal intensity ratios were 0.89 +/- 0.04 versus 0.77 +/- 0.02 on T1-weighted images (P = .002); 1.66 +/- 0.28 versus 0.88 +/- 0.14 on T2-weighted images (P = .003); and 2.16 +/- 0.29 versus 1.77 +/- 0.26 on postcontrast T1-weighted images (P = .01).
  
  
  CONCLUSIONS
  Intra- and extracranial components of JFM display different signal intensity and enhancement patterns. These differences may be related to histologic composition, and in particular, collagen content.
authors.affiliation: Department of Radiology, Kinki University School of Medicine, Osaka, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Shimono
authors.forename: Fumiharu
authors.initials: F
authors.lastname: Akai
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kanagaki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Fushimi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Maeda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007601:Jugular Veins; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology*; D008579:Meningioma / Q000473:pathology*; D008875:Middle Aged; D012189:Retrospective Studies