The Power of Power Doppler: Ultrasound Imaging in RA

In a study by Ziegelasch et al., 82 patients positive for anti-citrullinated protein antibodies (ACPA) but without clinical signs of arthritis were examined with baseline ultrasound for synovial hypertrophy, inflammatory activity by power Doppler and erosions in small joints of hands and feet. In this study, the authors found that clinical arthritis development was more common in patients with baseline ultrasound erosions than those without (77% vs. 42%, P=0.032).⁴

These studies indicate that baseline ultrasound imaging may be helpful in predicting which patients with undifferentiated arthritis, or with risk factors for RA (such as ACPA positivity) but no clinical arthritis, may be likely to progress to RA in the future.

Evaluating Disease Activity

In contrast to using ultrasound to aid in diagnosis, the evidence for using ultrasound to assist in evaluating disease activity and guiding treatment in patients with RA is less compelling. Dale et al. sought to evaluate if an intensive early RA treat-to-target strategy could be improved by using ultrasound assessment to help evaluate disease activity.⁵

Some 111 newly diagnosed patients with RA or undifferentiated arthritis (symptom duration of less than one year) were enrolled and then randomized to the control group, in which disease-modifying anti-rheumatic drug (DMARD) escalation was based on the Disease Activity Score-28 for rheumatoid arthritis with erythrocyte sedimentation rate (DAS28-ESR) alone, or the intervention group, in which DMARD escalation was based on a combined DAS28-ESR score and ultrasound evaluation.

The co-primary outcomes were mean change from baseline of DAS44 score and RA magnetic resonance imaging (MRI) scoring system (RAMRIS) erosion score. Although the intervention group received more intensive DMARD therapy over the course of the study, no significant between-group differences in DAS44 score or RAMRIS erosion score were seen.⁵

Similar findings were seen in a separate study from Scandinavia, in which the authors concluded that the systematic use of ultrasound in the follow-up of patients with early RA is not justified at present.⁶

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Jason Liebowitz, MD, completed his fellowship in rheumatology at Johns Hopkins University, Baltimore, where he also earned his medical degree. He is currently in practice with Skylands Medical Group, N.J.

 

References

1. Bruyn GAW, Siddle HJ, Hanova P, et al. Ultrasound of subtalar joint synovitis in patients with rheumatoid arthritis: Results of an OMERACT reliability exercise using consensual definitions. J Rheumatol. 2019 Apr;46(4):351–359.
2. Kang T, Lanni S, Nam J, et al. The evolution of ultrasound in rheumatology. Ther Adv Musculoskelet Dis. 2012 Dec;4(6):399–411.
3. Horton SC, Tan AL, Wakefield RJ, et al. Ultrasound-detectable grey scale synovitis predicts future fulfilment of the 2010 ACR/EULAR RA classification criteria in patients with new-onset undifferentiated arthritis. RMD Open. 2017 Mar 30;3(1):e000394.
4. Ziegelasch M, Eloff E, Hammer HB, et al. Bone erosions detected by ultrasound are prognostic for clinical arthritis development in patients with ACPA and musculoskeletal pain. Front Med (Lausanne). 2021 Mar 23;8:653994.
5. Dale J, Stirling A, Zhang R, et al. Targeting ultrasound remission in early rheumatoid arthritis: The results of the TaSER study, a randomised clinical trial. Ann Rheum Dis. 2016 Jun;75(6):1043–1050.
6. Haavardsholm EA, Aga AB, Olsen IC, et al. Ultrasound in management of rheumatoid arthritis: ARCTIC randomised controlled strategy trial. 2016 Aug 16;354:i4205.