title: Quantitative ultrasound tissue characterization in shoulder and thigh muscles--a new approach.
abstract: BACKGROUND
  The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: (1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and (2) to use the method for characterization of ultrasound images of the supraspinatus muscle, and the vastus lateralis muscle.
  
  
  METHODS
  Computerized texture analyses employing first-order and higher-order grey-scale statistics were developed to objectively characterize ultrasound images of m. supraspinatus and m. vastus lateralis from 9 healthy participants.
  
  
  RESULTS
  The mean grey-scale intensity was higher in the vastus lateralis muscle (p < 0.05) than in the supraspinatus muscle (average value of middle measuring site 51.4 compared to 35.0). Furthermore, the number of spatially connected and homogeneous regions (blobs) was higher in the vastus lateralis (p < 0.05) than in the supraspinatus (average for m. vastus lateralis: 0.092 mm(-2) and for m. supraspinatus: 0.016 mm(-2)).
  
  
  CONCLUSIONS
  The higher intensity and the higher number of blobs in the vastus lateralis muscle indicates that the thigh muscle contained more non-contractile components than the supraspinatus muscle, and that the muscle was coarser. The image analyses supplemented each other and gave a more complete description of the tissue composition in the muscle than the mean grey-scale value alone.
authors.affiliation: Department of Physiology, National Institute of Occupational Health, Denmark. pkn@ami.dk
authors.forename: Pernille Kofoed
authors.initials: PK
authors.lastname: Nielsen
authors.forename: Bente R
authors.initials: BR
authors.lastname: Jensen
authors.forename: Tron
authors.initials: T
authors.lastname: Darvann
authors.forename: Kurt
authors.initials: K
authors.lastname: Jørgensen
authors.forename: Merete
authors.initials: M
authors.lastname: Bakke
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging*; D012782:Shoulder / Q000000981:diagnostic imaging*; D013848:Thigh / Q000000981:diagnostic imaging*; D014463:Ultrasonography