title: Influence of recent exercise and skin temperature on ultrasound Doppler measurements in patients with rheumatoid arthritis--an intervention study.
abstract: OBJECTIVE
  Use of ultrasound Doppler (USD) in diagnosing and treatment monitoring of patients with RA has increased considerably. Hyperaemia is an integral part of the inflammatory response, and the amount of USD activity in an inflamed synovium may therefore be used to quantify the inflammatory activity. It is unclear, however, whether the hyperaemia alone reflects the disease activity or may be influenced by other factors.
  
  
  METHODS
  Twenty-nine patients with RA underwent USD examination of the wrist before and immediately after three interventions. The interventions were carried out on three separate days. The interventions were (i) isometric exercise of the muscles of the hand and forearm, (ii) heating and (iii) cooling of the hand. The amount of Doppler in the wrist joint was quantified by measuring the percentage of colour in the synovium-the colour fraction (CF). The CF values estimated before and after each intervention were compared to see if any intervention affected the amount of Doppler in the synovium.
  
  
  RESULTS
  The CF decreased significantly after cooling of the hand (P = 0.018 and <0.0001). Despite being highly significant, the numerical decrease in CF was only modest, 0.78-1.33 percentage points. The other interventions did not affect the CF significantly, with P-values of 0.65 and 0.59 in the heating intervention and 0.49 in the exercise intervention.
  
  
  CONCLUSIONS
  Cooling of the hand should, if possible, be avoided before a USD examination of the wrist in patients with RA, because the amount of Doppler activity might be affected by low skin temperatures.
authors.affiliation: The Parker Institute, Frederiksberg Hospital, Frederiksberg, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Ellegaard
authors.forename: Søren
authors.initials: S
authors.lastname: Torp-Pedersen
authors.forename: Marius
authors.initials: M
authors.lastname: Henriksen
authors.forename: Hans
authors.initials: H
authors.lastname: Lund
authors.forename: Bente
authors.initials: B
authors.lastname: Danneskiold-Samsøe
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003080:Cold Temperature; D015444:Exercise; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D012881:Skin Temperature; D013583:Synovial Membrane / Q000000981:diagnostic imaging; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D014955:Wrist Joint / Q000000981:diagnostic imaging