title: Texture analysis for tissue discrimination on T1-weighted MR images of the knee joint in a multicenter study: Transferability of texture features and comparison of feature selection methods and classifiers.
abstract: OBJECTIVE
  To investigate the reproducibility and transferability of texture features between MR centers, and to compare two feature selection methods and two classifiers.
  
  
  METHODS
  Coronal T1-weighted MR images of the knees of 63 patients, divided into three groups, were included in the study. MR images were obtained at three different MR centers. Regions of interest (ROIs) were drawn in the bone marrow and fat tissue. Then texture analysis (TA) of the ROIs was performed, and the most discriminant features were identified using Fisher coefficients and POE+ACC (probability of classification error and average correlation coefficients). Based on these features, artificial neural network (ANN) and k-nearest-neighbor (k-NN) classifiers were used for tissue discrimination.
  
  
  RESULTS
  Although the texture features differed among the MR centers, features from one center could be successfully used for tissue discrimination in texture data on MR images from other centers. The best results were achieved using the ANN classifier in combination with features selected by POE+ACC.
  
  
  CONCLUSIONS
  The differences in texture features extracted from MR images from different centers seem to have only a small impact on the results of tissue discrimination.
authors.affiliation: Osteoradiology Section, Department of Radiology, Medical University of Vienna, Austria. marius_mayerhoefer@aon.at
authors.forename: Marius E
authors.initials: ME
authors.lastname: Mayerhoefer
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Breitenseher
authors.forename: Josef
authors.initials: J
authors.lastname: Kramer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Aigner
authors.forename: Siegfried
authors.initials: S
authors.lastname: Hofmann
authors.forename: Andrzej
authors.initials: A
authors.lastname: Materka
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D000465:Algorithms; D001185:Artificial Intelligence; D001853:Bone Marrow / Q000473:pathology; D001855:Bone Marrow Diseases / Q000473:pathology*; D004487:Edema / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity