title: Higher-Resolution Magnetic Resonance Elastography in Meningiomas to Determine Intratumoral Consistency.
abstract: BACKGROUND
  Magnetic resonance elastography (MRE) analyzes shear wave movement through tissue to determine stiffness. In a prior study, measurements with first-generation brain MRE techniques correlated with intraoperative observations of overall meningioma stiffness.
  
  
  OBJECTIVE
  To evaluate the diagnostic accuracy of a higher-resolution MRE technique to preoperatively detect intratumoral variations compared with surgeon assessment.
  
  
  METHODS
  Fifteen meningiomas in 14 patients underwent MRE. Tumors with regions of distinctly different stiffness were considered heterogeneous. Intratumoral portions were considered hard if there was a significant area ≥6 kPa. A 5-point scale graded intraoperative consistency. A durometer semiquantitatively measured surgical specimen hardness. Statistics included χ, sensitivity, specificity, positive and negative predicative values, and Spearman rank correlation coefficient.
  
  
  RESULTS
  For MRE and surgery, 9 (60%) and 7 (47%) tumors were homogeneous, 6 (40%) and 8 (53%) tumors were heterogeneous, 6 (40%) and 10 (67%) tumors had hard portions, and 14 (93%) and 12 (80%) tumors had soft portions, respectively. MRE sensitivity, specificity, and positive and negative predictive values were as follows: for heterogeneity, 75%, 100%, 100%, and 87%; for hardness, 60%, 100%, 100%, and 56%; and for softness, 100%, 33%, 86%, and 100%. Overall, 10 tumors (67%) matched well with MRE and intraoperative consistency and correlated between intraoperative observations (P = .02) and durometer readings (P = .03). Tumor size ≤3.5 cm or vascular tumors were more likely to be inconsistent (P < .05).
  
  
  CONCLUSIONS
  MRE was excellent at ruling in heterogeneity with hard portions but less effective in ruling out heterogeneity and hard portions, particularly in tumors more vascular or <3.5 cm. MRE is the first technology capable of prospectively evaluating intratumoral stiffness and, with further refinement, will likely prove useful in preoperative planning.
authors.affiliation: *Departments of Neurologic Surgery and ‡Radiology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Hughes
authors.forename: Nikoo
authors.initials: N
authors.lastname: Fattahi
authors.forename: J
authors.initials: J
authors.lastname: Van Gompel
authors.forename: Arvin
authors.initials: A
authors.lastname: Arani
authors.forename: Fredric
authors.initials: F
authors.lastname: Meyer
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lanzino
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.forename: Richard
authors.initials: R
authors.lastname: Ehman
authors.forename: John
authors.initials: J
authors.lastname: Huston
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology / Q000601:surgery; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008579:Meningioma / Q000000981:diagnostic imaging* / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies