title: The usefulness of computer-aided joint space analysis in the assessment of rheumatoid arthritis.
abstract: OBJECTIVE
  Computer-aided joint space analysis (CAJSA) is a newly developed technique for the measurement of radiogeometrically detectable joint space widths of the metacarpal-phalangeal (JSD-MCP) and proximal-interphalangeal articulations (JSD-PIP). The aim of this study was to verify the sensitivity and specificity of these CAJSA measurements in the assessment of established RA.
  
  
  METHODS
  Four hundred and fifty-eight participants (248 healthy subjects, 210 RA patients) underwent computerized semi-automated measurements of the JSD-MCP and JSD-PIP articulations (CAJSA, Radiogrammetry Kit, Version 1.3.6) based on digitally performed radiographs. The Sharp joint space narrowing score was also performed to determine RA-related joint space narrowing.
  
  
  RESULTS
  The significant severity-dependent reduction for JSD-MCP was -44.0% and for JSD-PIP, -25.94% between Sharp scores 0 and 3. The sensitivity and specificity of JSD-MCP (total) was 88.1% versus 77.8%, respectively (AUC = 0.920; P < 0.001). Furthermore, JSD-PIP (total) revealed a lower sensitivity and specificity with 61.4% and 88.7% (AUC = 0.878; P < 0.001).
  
  
  CONCLUSIONS
  The CAJSA method presented a reliable assessment of disease-related joint space narrowing in patients suffering from RA with excellent sensitivity and specificity. By providing quantitative data, other scoring methods could be significantly improved, and thereby the accuracy of the diagnosis and a better therapeutic evaluation could be achieved.
authors.affiliation: Department of Internal Medicine III, Jena University Hospital, Friedrich Schiller University Jena, Erlanger Allee 101, 07747 Jena, Germany. alexander.pfeil@med.uni-jena.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Pfeil
authors.forename: Diane M
authors.initials: DM
authors.lastname: Renz
authors.forename: Andreas
authors.initials: A
authors.lastname: Hansch
authors.forename: Franz
authors.initials: F
authors.lastname: Kainberger
authors.forename: Gabriele
authors.initials: G
authors.lastname: Lehmann
authors.forename: Ansgar
authors.initials: A
authors.lastname: Malich
authors.forename: Gunter
authors.initials: G
authors.lastname: Wolf
authors.forename: Joachim
authors.initials: J
authors.lastname: Böttcher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index