title: Analysis of the factors which influence the measurement of synovial power Doppler signals with semi-quantitative and quantitative measures - a pilot multicenter exercise in Japan.
abstract: OBJECTIVE
  This pilot multicenter exercise aimed to evaluate the inter-observer reproducibility of synovial power Doppler (PD) signals in rheumatoid arthritis (RA) patients and to determine the factors influencing the measurements.
  
  
  METHODS
  Two representative RA patients were assessed by four independent experienced sonographers. The influence of machine difference, deterioration of the transducer and pulse repetition frequency (PRF) on the assessment of synovial PD signals was investigated.
  
  
  RESULTS
  Intra-class correlation coefficient (ICC) for the scanner-reader reproducibility of semi-quantitative PD score was high (0.867). ICC for the inter-scanner reproducibility of synovial PD pixel count was higher than that of semi-quantitative PD score. The assessment of PD signals significantly differed between two machines with quantitative measurements but did not with semi-quantitative score. The assessment of PD signals with a deteriorated transducer was much less sensitive than that with an intact one. The semi-quantitative scores for PD signals were comparable between three different PRFs (500/800/1,300 Hz), whereas the pixel count was significantly lower with the highest one in the knee joint.
  
  
  CONCLUSIONS
  Measurement of PD signal can be substantially affected by deteriorated quality of the transducer, whereas the differences are relatively modest between machines with similar specifications and also between PRF settings within a low range.
authors.affiliation: Department of Allergy and Clinical Immunology, Chiba University Hospital , Chiba , Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ikeda
authors.forename: Yohei
authors.initials: Y
authors.lastname: Seto
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohno
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Sakamoto
authors.forename: Mihoko
authors.initials: M
authors.lastname: Henmi
authors.forename: Jun
authors.initials: J
authors.lastname: Fukae
authors.forename: Akihiro
authors.initials: A
authors.lastname: Narita
authors.forename: Daiki
authors.initials: D
authors.lastname: Nakagomi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Tanimura
authors.forename: Takao
authors.initials: T
authors.lastname: Koike
mesh_terms: D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007564:Japan; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D013583:Synovial Membrane / Q000000981:diagnostic imaging*; D013585:Synovitis / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler