Musculoskeletal Ultrasound Aids in Diagnosis & Disease Management of RA & PsA
WASHINGTON, D.C.—At a Nov. 15 session of ACR Convergence, speakers shared insights from their ongoing work on the updated guidance document on the use of musculoskeletal ultrasound (MSUS) for rheumatoid arthritis (RA) and psoriatic arthritis (PsA). The panel emphasized the importance of the supplementary tool in clinical decision making and patient collaboration.
Evolution of MSUS
For the past two years, researchers have been working through the stages of guidance document production, from the development of initial PICO (Patient/Intervention/Comparison/Outcome) questions, literature search and voting processes. The goal was to update the ACR’s 2012 report, creating two different guidance documents for RA and PsA that reflect the changing landscape of ultrasound in rheumatology.1
Dr. Ranganath
One of the clinicians working on the guidance documents is Veena K. Ranganath, MD, MS, RhMSUS, co-director of the UCLA Masters of Science in Clinical Research Program and director of the Rheumatology Fellowship Musculoskeletal Ultrasound Training Program, University of California, Los Angeles.
Dr. Ranganath pointed out that in the last 12 years, MSUS technology has significantly improved, and substantive advancements have been made in systems for ultrasound scoring and defining ultrasound features. Research interest in the area has increased substantially, and ultrasound has become more widely used in clinical practice, in part because of educational efforts by the ACR, EULAR and the Ultrasound School of North American Rheumatologists (USSONAR).
“New therapeutic agents and treatment strategies have emerged for both RA and PsA, and that definitively impacts the question of how to incorporate musculoskeletal ultrasound into our clinical practices,” said Dr. Ranganath.
The following is a discussion of a selection of the approved guidance statements discussed in the session at ACR Convergence.
Guiding Diagnosis
The Voting Panel reached strong consensus that adding MSUS to the clinical exam can aid in both the diagnosis of early RA and early PsA in patients with psoriasis and musculoskeletal symptoms, promoting earlier intervention.
Gurjit Kaeley, MBBS, RhMSUS, MRCP, a rheumatologist and a professor in the Department of Medicine at the University of Florida, Jacksonville, who has been working on the guidance document, explained that ultrasound is more sensitive than clinical exam in detecting synovitis. Studies suggest that adding sonography improves the prediction of the development of RA.
“Patients’ ultrasounds—especially with Doppler technique—provide critical insights into disease activity and structural changes not always apparent during standard clinical examinations,” he said.
Dr. Bakewell
Another guidance document contributor and speaker was Catherine Bakewell, MD, RhMSUS, a rheumatologist with Intermountain Medical Group in Salt Lake City. Dr. Bakewell explained that the information obtained via ultrasound, such as inflammation of the joints or enthesis, can increase the number of patients who qualify for a classification of PsA by the CASPAR classification criteria, as demonstrated by several studies.
Evaluating Disease Activity & Progression
In both RA and PsA, MSUS can be used to help evaluate current disease activity, informing decisions to escalate or de-escalate therapy. Example: MSUS with clinical examination confirms RA flares more effectively than clinical exam alone (moderate consensus). Similarly, sonographic features can inform the decision to escalate therapy in PsA (strong consensus).
Subclinical inflammation detected via MSUS also provides insights into clinical disease activity in both disease states, providing critical information for management. “Patients can have a clinically normal exam and in fact have ongoing synovitis,” said Dr. Bakewell. “But the converse can also be true. You can have a patient who has a swollen joint [but not active synovitis].”
Signs of synovitis on MSUS can help identify both patients with early and established RA who are at higher risk of radiographic progression and poorer patient-reported outcomes. Similarly, synovitis and enthesitis can also predict radiographic progression and worsening of patient-related outcomes in PsA. Dr. Kaeley pointed out that this approach can help clinicians form more tailored and effective interventions.
Specific Sites & Findings
For both disorders, a positive joint finding that demonstrates inflammation and supports a potential diagnosis of RA or PsA is a grayscale-type ultrasound graded ≥2 or a grayscale-type ultrasound graded ≥1 along with a power Doppler-type ultrasound graded ≥1 (both moderate consensus).
Detection of synovitis, tenosynovitis and erosions can aid in the diagnosis of early RA, reflected in a strong consensus statement. Tenosynovitis, specifically, can be an important predictor of the future development of RA, particularly in subjects with positive serology. These same ultrasound findings can be used to help predict risk of flare while on continued therapy or in response to medication tapering.
A related strong consensus statement was for the use of musculoskeletal ultrasound on the wrist joints and the second and third metacarpophalangeal and second and third proximal interphalangeal joints in RA. However, Dr. Kaeley emphasized, “The sonographer and clinician also need to address areas of concern based on clinical factors.” MSUS of these same joints can be used for treatment monitoring, as well as evaluation for remission, if applicable.
Dr. Bakewell noted the entheseal features that can be used to support a diagnosis of PsA: hypoechogenicity, thickening, Doppler signal, bone erosions, enthesophytes/calcifications and bursal enlargement, although she noted that none of these signals are specific to PsA. These signals can also be used to evaluate potential disease flare or to evaluate a potential remission, in addition to other signals, such as those specifically defined for dactylitis.
Additionally, in diagnosing patients with psoriasis with early PsA, one should examine at a minimum the bilateral quadriceps tendon, patellar ligament, Achilles tendon and plantar fascia entheses. In assessing patients with psoriasis for potential PsA, ultrasound should include scans of the hand, wrist, foot and relevant symptomatic joints.
Use in Selection Populations & Collaborative Care
Negative treat-to-target clinical trials employing a strictly scheduled use of MSUS failed their primary end points, which may have dissuaded some in the rheumatology community of the benefit of this modality.2,3 However, Dr. Bakewell responded that this finding doesn’t demonstrate an overall lack of utility. She noted that MSUS is not required for every patient at every visit, and it should only be used if certain clinical questions need to be addressed. Moreover, it may benefit certain populations more than others.
Dr. Kaeley emphasized that MSUS can help distinguish RA-related inflammation from other non-RA inflammatory conditions, such as gout. This nuance may be especially helpful to clarify the source of pain in some difficult-to-treat patients.
MSUS may also be helpful guiding treatment in patients with other comorbidities, such as RA and fibromyalgia. Dr. Kaeley said, “Patients with RA and fibromyalgia tend to have more steroid exposure and a higher prevalence of biologic use [compared with those with RA only], because the composite disease scores tend to overestimate disease activity in these patients, especially when compared with ultrasound.”
MSUS may be helpful in patients who have a difficult physical exam (e.g., obese patients), and it may help reduce physician bias in evaluating elderly patients. Dr. Kaeley noted it can also be particularly beneficial if the patient and provider impressions of joint activity are non-concordant to help clarify the actual clinical status.
The same principles apply to PsA. Dr. Bakewell noted that it can be helpful both for reassuring a patient with comorbid noninflammatory pain, but also for educating patients whose MSUS may show more inflammation than indicated by their perceived pain.
The Voting Panel has currently reached consensus on 55 guidance statements in total, with an additional five statements going back for reconsideration in a second round of voting. This progress will be followed by manuscript creation and review by the ACR, USSONAR and the journal of publication. The release date for the future full document is not yet known.
Ruth Jessen Hickman, MD, a graduate of the Indiana University School of Medicine, is a medical and science writer in Bloomington, Ind.
References
- McAlindon T, Kissin E, Nazarian L, et al. American College of Rheumatology report on reasonable use of musculoskeletal ultrasonography in rheumatology clinical practice. Arthritis Care Res (Hoboken). 2012;64(11):1625–1640.
- Haavardsholm EA, Aga A-B, Olsen IC. et al. Ultrasound in management of rheumatoid arthritis: ARCTIC randomised controlled strategy trial. BMJ. 2016 Aug 16;354:i4205.
- 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.