RESEARCH - Ultrasound color Doppler measurements in a single joint as a measure of disease activity in RA

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Rheumatology Advance Access originally published online on January 7, 2009

Rheumatology 2009 48(3):254-257; doi:10.1093/rheumatology/ken459

Ultrasound colour Doppler measurements in a single joint as measure of

disease activity in patients with rheumatoid arthritis—assessment of

concurrent validity

K. Ellegaard1, S. Torp-Pedersen1, L. Terslev1, B. Danneskiold-Samsøe1,

M. Henriksen1 and H. Bliddal1

1The Institute, Frederiksberg Hospital, Frederiksberg, Denmark.

Abstract

Objective. Colour Doppler ultrasound (CDU) displays blood flow in the

tissues and is able to detect hyperaemia. Because hyperaemia is part

of the inflammatory response, the amount of CDU activity in the

inflamed synovium may be used to quantify the inflammatory activity in

RA. It has never been investigated if the amount of CDU activity in a

single joint can be used to quantify disease activity in RA.

Methods. A total of 109 patients with RA and affection of the wrist

joint underwent a standardized CDU examination assessing three

positions in their most affected wrist at start up in biological

treatment. On the same day the following measures of disease activity

were collected: assessment of the number of tender and swollen joints,

CRP, ESR and 28-joint disease activity score (DAS28).

The amount of CDU activity was quantified by measuring the percentage

of colour in the synovium—the colour fraction (CF). Correlation

between CF and other measures of disease activity was calculated.

Results. There was a significant correlation between CF and DAS28 (r =

0.29; P < 0.001), swollen joint count (r = 0.35; P < 0.001), CRP (r =

0.5; P < 0.001) and ESR (r = 0.5; P < 0.001). No other significant

correlations were found.

Conclusion. A standardized ultrasound examination of a single affected

wrist joint in patients with RA may be used as a measure of disease

activity. More studies are needed to identify the number of joints

needed to examine by CDU to obtain the best validity of Doppler

measurements.

http://rheumatology.oxfordjournals.org/cgi/content/abstract/48/3/254

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