title: Measurement consistency of MR elastography at 3.0 T: comparison among three different region-of-interest placement methods.
abstract: OBJECTIVE
  To test inter- and intraobserver consistency of liver stiffness measurement on MR elastography (MRE) at 3.0 T.
  
  
  METHODS
  Two abdominal radiologists independently measured stiffness of the liver on MRE in three volunteers and seven patients with chronic liver diseases using three different region-of-interest (ROI) placement methods. Methods 1 and 2 involved placing circular and free-hand-drawn ROIs, respectively, visually referring to anatomical (three-dimensional T1-weighted) and wave images. Method 3 involved placing ROIs on the fused images of MRE and anatomical images developed on a work station, visually referring to wave images. The inter- and intraobserver consistency was assessed with regression and Bland-Altman analysis.
  
  
  RESULTS
  Thirty-eight images were available for measurement in total. As for interobserver consistency, method 3 showed the best regression coefficient, correlation coefficient, and y intercept. The absolute values of the interobserver differences for method 3 were significantly smaller than those of method 1 or method 2 (p < 0.05, each). Intraobserver consistency of method 3 was excellent for both observers.
  
  
  CONCLUSIONS
  Stiffness measurement of the liver on MRE performed with the fusion method at 3.0 T provides the highest inter- and intraobserver consistency.
authors: Department of Radiology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma Jonan-ku, Fukuoka 814-0180, Japan.
authors: Toshimichi
authors: T
authors: Mitsufuji
authors: Yoshinobu
authors: Y
authors: Shinagawa
authors: Ritsuko
authors: R
authors: Fujimitsu
authors: Hiroshi
authors: H
authors: Urakawa
authors: Kimiyo
authors: K
authors: Inoue
authors: Koichi
authors: K
authors: Takano
authors: Kengo
authors: K
authors: Yoshimitsu
mesh_terms: D000328:Adult; D000368:Aged; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver; D008107:Liver Diseases / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D015588:Observer Variation