title: The role of dynamic contrast-enhanced MRI in the differential diagnosis of psoriatic and rheumatoid arthritis.
abstract: OBJECTIVE
  The purpose of this study was to investigate the role of dynamic contrast-enhanced MRI in the differential diagnosis of psoriatic and rheumatoid arthritis in the hand and wrist.
  
  
  METHODS
  Forty-five consecutive patients (31 patients with rheumatoid arthritis and 14 patients with psoriatic arthritis) were examined in a 3-T whole-body MR unit. After contrast injection, a 3D encoded spoiled gradient-echo sequence was used for measurement of the time course of contrast-medium uptake in the synovial tissue. On the basis of the gained uptake curves, the rate of early enhancement was calculated after 35 and 52 seconds, and the relative enhancement rate was calculated after 35 seconds, 52 seconds, 3 minutes, and 15 minutes (late enhancement). Dynamic contrast-enhanced MRI rates of patients with rheumatoid arthritis and psoriatic arthritis were compared and correlated with laboratory and clinical data.
  
  
  RESULTS
  A statistically significant difference between the two groups was found regarding the relative enhancement rate after 15 minutes (p < 0.01). In contrast, no difference in relative enhancement rate was found 35 seconds, 52 seconds, or 3 minutes after contrast injection (p = 0.695, p = 0.573, and p = 0.278, respectively). Regarding the rate of early enhancement at 35 and 52 seconds, no significant difference between patients with rheumatoid arthritis and those with psoriatic arthritis was found. Significant correlations were found between inflammatory parameters and dynamic contrast-enhanced parameters in patients with rheumatoid arthritis but not in those with psoriatic arthritis.
  
  
  CONCLUSIONS
  Fifteen minutes after contrast injection, a statistically significant difference between rheumatoid arthritis and psoriatic arthritis was found in synovial enhancement that might play an important role in differentiating the two diseases.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany. nina.schwenzer@med.uni-tuebingen.de
authors.forename: Nina F
authors.initials: NF
authors.lastname: Schwenzer
authors.forename: Ina
authors.initials: I
authors.lastname: Kötter
authors.forename: Jörg C
authors.initials: JC
authors.lastname: Henes
authors.forename: Christina
authors.initials: C
authors.lastname: Schraml
authors.forename: Jan
authors.initials: J
authors.lastname: Fritz
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D015535:Arthritis, Psoriatic / Q000175:diagnosis*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006225:Hand / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D014955:Wrist Joint / Q000473:pathology
chemical_list: D015415:Biomarkers; D003287:Contrast Media; D019786:Gadolinium DTPA