Validity, reproducibility, and responsiveness of a twelve-joint simplified power doppler ultrasonographic assessment of joint inflammation in rheumatoid arthritis

Arthritis Rheum. 2008 Apr 15;59(4):515-22. doi: 10.1002/art.23529.


Objective: To investigate the validity, reproducibility, and responsiveness of a simplified power Doppler ultrasound (PDUS) assessment of joint inflammation compared with a comprehensive 44-joint PDUS assessment in patients with rheumatoid arthritis (RA) who started therapy with a biologic agent.

Methods: A total of 160 patients with active RA who started a biologic agent were prospectively recruited in 18 Spanish centers. The patients underwent clinical and laboratory assessment and blinded PDUS examination at baseline and 6 months. A PDUS examination of 128 synovial sites in 44 joints was performed. US synovitis and PD signal were semiquantitatively graded from 1 to 3 in all synovial sites. US count and index for synovitis and PD signal were obtained. PDUS intraobserver and interobserver reliability were evaluated. A process of data reduction based on the frequency of involvement of synovial sites by both synovitis and PD signal was conducted. Construct and discriminant validity of a simplified PDUS assessment was investigated.

Results: A PDUS simplified assessment including 24 synovial sites from 12 joints detected 100% of patients with synovitis and 91% of patients with PD signal. There was a highly significant correlation between the 44-joint count and index for synovitis and PD signal and the 12-joint count and index for synovitis and PD signal at baseline and 6 months (r = 0.84-0.90, P < 0.0005). The smallest detectable difference was lower than the mean change in simplified PDUS variables.

Conclusion: A 12-joint PDUS assessment of RA joint inflammation may be a valid, feasible method for multicenter monitoring of therapeutic response to biologic agents.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arthritis / diagnostic imaging
  • Arthritis, Rheumatoid / diagnostic imaging*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Reproducibility of Results
  • Ultrasonography, Doppler*