title: The rim pattern of meningioma on 3D FLAIR imaging: correlation with tumor-brain adhesion and histological grading.
abstract: OBJECTIVE
  We evaluated the rim patterns of intracranial meningiomas on nonenhanced (NE) and contrast-enhanced (CE) 3-dimensional fluid-attenuated inversion recovery (3D FLAIR) imaging on 3-tesla magnetic resonance (MR) imaging to clarify the associated imaging and pathological findings and the value of the rims in predicting tumor cleavability.
  
  
  METHODS
  Thirty-two patients with meningioma underwent tumor excision. We classified the rim patterns on 3D FLAIR, subdivided into "rim-NE," a rim with relatively low signal intensity on NE 3D FLAIR and "rim-CE," a rim with relatively high signal intensity on CE 3D FLAIR, into 4 grades by their extent from 0 (no rim visible) to 3 (rim visible over most of the tumor-brain interface) and correlated them with tumor size, grade of peritumoral brain edema, presence/absence of pial supply, grade of tumor-brain adhesion, and histological findings.
  
  
  RESULTS
  On NE 3D FLAIR, "rim-NE" was graded 0 in 5 patients, one in 5, 2 in 6, and 3 in 16. On CE 3D FLAIR, "rim-CE" was graded 0 in one patient, one in 13, 2 in 4, and 3 in 14. The grade of "rim-NE" correlated negatively with the grade of brain edema (P = 0.023) and positively with surgical tumor-brain cleavability (P < 0.001). It also correlated with the amount of connective tissue at the tumor-brain interface histologically (P = 0.041). Furthermore, a lower grade of "rim-NE" was more often seen in atypical than benign meningioma (P = 0.003). Although "rim-CE" was more prominent in tumors with pial supply on digital subtraction angiography (DSA) (P = 0.002), it was not useful in predicting tumor-brain adhesion or histological tumor grading.
  
  
  CONCLUSIONS
  The rim pattern of meningioma on NE 3D FLAIR can predict surgical cleavability and histological tumor grading. A higher grade of rim pattern on CE 3D FLAIR suggests prominent pial supply to the tumor but has no added value in predicting tumor-brain adhesion and histological tumor grading.
authors.affiliation: Department of Radiology, Nagasaki University Graduate School of Biomedical Sciences.
authors.forename: Mikako
authors.initials: M
authors.lastname: Enokizono
authors.forename: Minoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsuo
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Horie
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Honda
authors.forename: Reiko
authors.initials: R
authors.lastname: Ideguchi
authors.forename: Izumi
authors.initials: I
authors.lastname: Nagata
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D001929:Brain Edema / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D008579:Meningioma / Q000473:pathology* / Q000648:ultrastructure; D008875:Middle Aged; D060787:Neoplasm Grading; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media