Ultrasound and magnetic resonance imaging in the evaluation of psoriatic dactylitis: status and perspectives

Validation and incorporation of digital entheses into a preliminary GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis

OBJECTIVES

The main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and applicability of ultrasound assessment of finger entheses to incorporate them into the scoring system.

METHODS

The study consisted of a stepwise process. First, in cadaveric specimens, we identified enthesis sites of the fingers by ultrasound and gross anatomy, and then verified presence of entheseal tissue in histological samples. We then selected the entheses to be incorporated into a dactylitis scoring system through a Delphi consensus process among international experts. Next, we established and defined the ultrasound components of dactylitis and their scoring systems using Delphi methodology. Finally, we tested the interobserver and intraobserver reliability of the consensus- based scoring systemin patients with psoriatic dactylitis.

RESULTS

32 entheses were identified in cadaveric fingers. The presence of entheseal tissues was confirmed in all cadaveric samples. Of these, following the consensus process, 12 entheses were selected for inclusion in GLOUDAS. Ultrasound components of GLOUDAS agreed on through the Delphi process were synovitis, tenosynovitis, enthesitis, subcutaneous tissue inflammation and periextensor tendon inflammation. The scoring system for each component was also agreed on. Interobserver reliability was fair to good (κ 0.39-0.71) and intraobserver reliability good to excellent (κ 0.80-0.88) for dactylitis components. Interobserver and intraobserver agreement for the total B-mode and Doppler mode scores (sum of the scores of the individual abnormalities) were excellent (interobserver intraclass correlation coefficient (ICC) 0.98 for B-mode and 0.99 for Doppler mode; intraobserver ICC 0.98 for both modes).

CONCLUSIONS

We have produced a consensus-driven ultrasound dactylitis scoring system that has shown acceptable interobserver reliability and excellent intraobserver reliability. Through anatomical knowledge, small entheses of the fingers were identified and histologically validated.

High-resolution ultrasound imaging of elementary lesions in dactylitis

OBJECTIVE

The aim of the present study was to illustrate the (potential) diagnostic role of high resolution US images in assessing the elementary lesions of dactylitis.

METHODS

Using high-frequency US machines/probes, we matched the micro-anatomical cadaveric architecture of the digit with multiple sonographic findings of dactylitis. High-sensitive color/power Doppler assessments have also been performed to evaluate the digital microvasculature.

DISCUSSION

Modern US equipment/features guarantee prompt and in-depth B-mode and color/power Doppler imaging of tiny anatomical structures of the digit which are usually not properly visible with standard US machines. More specifically, hypervascularization of the digital subcutaneous tissue, fibrous pulleys of flexor tendons, dorsal synovial pads as well as pathological changes of the distal entheseal anchorage network can be accurately detected.

CONCLUSION

In clinical practice, high-end US equipment can be used to accurately assess the digits in patients with dactylitis. This way, simple and convenient sonographic diagnosis of different elementary lesions can be timely established.

Ultrasonographic Insights into Peripheral Psoriatic Arthritis: Updates in Diagnosis and Monitoring

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis, characterized by heterogeneous clinical manifestations and variable disease progression. Ultrasonography has emerged as a valuable tool in the diagnosis and monitoring of PsA, providing real-time visualization of joint and soft tissue abnormalities. This review highlights recent advancements in ultrasonographic techniques for the assessment of PsA, including the identification of typical features, the role of power Doppler imaging in detecting active inflammation, and the potential of ultrasound for guiding treatment decisions. Additionally, we discuss the utility of ultrasound in assessing treatment response and monitoring disease progression in patients with PsA, with a focus on novel imaging modalities. By elucidating the evolving role of ultrasonography in PsA management, this article aims to enhance clinicians' understanding of its utility in facilitating early diagnosis, optimizing treatment strategies, and improving patient outcomes.

Value of Hands Ultrasonography in the Differential Diagnosis Between Psoriatic Arthritis and Rheumatoid Arthritis

OBJECTIVES

Psoriatic arthritis (PsA) can mimic rheumatoid arthritis (RA) at an early stage, especially when psoriasis is lacking. In the absence of specific radiological and immunological markers, the differential diagnosis between these two diseases can be challenging. We aimed to determine whether hands ultrasonography (US) may be useful in the differential diagnosis between PsA and RA.

METHODS

We conducted a cross-sectional study including patients with PsA and RA. All wrists and small joints of the hands were examined using gray-scale and Power Doppler US. The evaluated US lesions were: synovitis, tenosynovitis of extensor carpi ulnaris, extensor communis and flexor tendons, enthesitis of extensor tendons at distal interphalangeal joints, peritendon inflammation of extensor tendons, and soft tissue edema.

RESULTS

Six hundred joints in 20 PsA patients and 900 joints in 30 RA patients were assessed. Extensor enthesitis was significantly more observed in PsA compared with RA (39.4 vs 26.3%, P = .006) with a significant higher frequency of enthesophytes and calcifications (P = .022 and P = .002, respectively). Peritendon inflammation of extensor digitorum tendons was observed in 13% of metacarpophalangeal joints in PsA patients versus 3% in RA patients with a significant difference (P < .001). Soft tissue edema was exclusively observed in PsA (1.5 vs 0%, P = .033). Power Doppler synovitis was significantly more frequent in RA (9.2 vs 5%, P = .002). Extensor carpi ulnaris tenosynovitis was significantly more frequent in RA (18.3 vs 2.5%, P = .017).

CONCLUSION

Extrasynovial US findings may be helpful to distinguish PsA from RA especially in patients with immunonegative polyarthritis and no evidence of psoriasis.

Morphologic, dynamic and high-resolution microscopy MRI in early-onset spondyloarthritis finger dactylitis

OBJECTIVE

Up to now, the pathophysiology of SpA dactylitis has not been entirely clarified. It is not clear which are the involved tissues and which is the primary lesion of the "sausage-like" digit. The aim of our study was to examine the finger structures in early-onset finger dactylitis using high-resolution microscopy MRI together with morphologic and dynamic MRI.

SUBJECTS AND METHODS

In a 6-month period, 13 SpA patients (7 females and 6 males), mean age 54.07 years (range 37-73 years) and mean disease duration 7.07 years (range 1-44 years) with early-onset finger dactylitis (less than 3 months) were recruited. Nine patients had PsA, 3 HLA-B27-positive uSpA and 1 HLA-B27-negative uSpA. One patient had 2 dactylitis fingers. Ten healthy volunteers matched for age and sex with no personal and family history of SpA were enrolled. All dactylitis fingers and randomly selected fingers of the normal control subjects were imaged by morphologic, dynamic and high-resolution microscopy MRI.

RESULTS

We have found flexor tenosynovitis in all the 14 dactylitis fingers, joint synovitis in 5 and oedema in the finger soft tissue in 10. In 2 dactylitis fingers, there was oedema at the insertion of the joint capsule suggesting enthesitis. In 5 dactylitis fingers, there was only mild enhancement at the enthesis organ (collateral ligament, flexor and extensor tendons).

CONCLUSIONS

Our MRI study on early-onset dactylitis demonstrates that flexor tenosynovitis, joint synovitis and oedema of the digit soft tissue are the predominant alterations visible in the early phase of evolution of dactylitis and that, therefore, enthesitis may not be considered the primary lesion of dactylitis.

OA12 Dactylitis in PsA: aetiology, clinical significance, & treatment implications

Introduction/Background

Dactylitis is a hallmark feature of PsA (PsA) and related spondyloarthritides and may affect up to half of PsA patients during the course of their disease(1). Presence of dactylitis may imply a more aggressive disease phenotype; dactylitis at presentation is associated with higher swollen and tender joint counts, higher systemic inflammatory response, presence of ultrasound-detected inflammation and erosions(2), as well as radiographic joint progression(3). Trial data suggest treatments used in PsA may not be equally effective against dactylitis(4).

Description/Method

A 55-year-old man was referred to rheumatology with several months of pain in the right index finger. He was unable to hold a pen, use a computer, or play golf. He had chronic plaque psoriasis since late 20s. On examination, right index finger was mildly swollen, suggestive of dactylitis, and flexion was restricted. No other joints or digits were affected. Inflammatory markers and x-rays of hands and feet were normal. A diagnosis of PsA was made. He had been reviewed by dermatology a few months earlier and started on apremilast; his finger seemed to be improving, so apremilast was continued and etodolac added PRN.

Over the next 2 years he reported short-lived episodes of finger pain but had no objective abnormalities when assessed in clinic. He then developed more persistent left hand pain and stiffness, was felt to have wrist and MCP synovitis, and started on sulfasalazine 1.5g daily, with symptomatic improvement.

Two years later he reported pain in the right hand, with inability to make a fist or play golf. Clinically he had synovitis at the right 4th PIPJ, and soft tissue swelling affecting the 2nd and 3rd fingers. He was given an IM glucocorticoid and sulfasalazine dose was increased to 3g daily. After 3 months he had ongoing difficulty bending the right 4th finger, and mild proximal swelling, and was referred for ultrasound. This showed PIP synovial hypertrophy, an inflamed extensor tendon, marked flexor tenosynovitis, and soft tissue swelling, consistent with dactylitis. He underwent guided injection to the flexor tendon sheath. Four weeks later he reported complete resolution of pain, and 90% improvement in swelling and function. Very recent x-rays of hands and feet showed no visible erosions in the hands, but a large juxta-articular erosion in the right middle toe.

Discussion/Results

This is a case of PsA characterised by isolated finger dactylitis at presentation, and dactylitis as a prominent feature of flare over time.

In general, dactylitis is more common in feet than hands, implicating mechanical stress as a key aetiopathogenetic driver. This patient was a keen golfer, which may explain predominant involvement of his right (dominant) hand 2nd, 3rd and 4th fingers.

While dactylitis is a key disease domain in PsA and other spondyloarthritides, it is not specific to these conditions, and other differentials should be considered depending on specific context, e.g. soft tissue infection or gout. While the diagnosis of PsA seems well-established here, a recent foot x-ray showed a middle toe punched out juxta-articular inter-phalangeal erosion, more typical of gout.

As well as an indicator of arthritis severity and a poor prognostic factor for radiographic progression, the number of dactylitic digits has been shown to be associated with major cardiovascular events, independent of traditional risk factors(5). Presence of dactylitis should perhaps prompt particularly careful assessment of cardiovascular risk.

Recent international (GRAPPA) guidelines give strong recommendations for all targeted therapies commonly used in PsA, including anti-TNF, anti-IL17, anti-IL12/23, anti-IL23, JAKi, and apremilast. NSAIDs, local steroid injections and methotrexate are conditionally recommended “for”, while other csDMARDs are conditionally recommended “against”(4). Whether sulfasalazine is truly less effective in this specific disease domain, or this simply represents a lack of supporting evidence, is debatable. In this case, the combination of apremilast and sulfasalazine was reasonably successful, but further flares might warrant a change in therapy, taking account of the dactylitis history.

In cases of uncertainty, ultrasound can be useful for confirmation of dactylitis(6), and/or differentiating between acute (“hot”) dactylitis and chronic (“cold”) dactylitis. The involvement of multiple structures and soft tissues can be visualised and appreciated.

Key learning points/Conclusion

Dactylitis is a hallmark feature of PsA and may be the sole musculoskeletal manifestation. Mechanical stress appears to be an important factor in aetiopathogenesis. Differentials others than spondyloarthritis should be considered. Presence of dactylitis tends to imply a more aggressive PsA phenotype and may have clinical relevance beyond the joints, including increased cardiovascular risk. Assessment for dactylitis should be performed when evaluating disease activity across psoriatic disease domains, and presence of dactylitis incorporated into decisions about treatment.

Normal and abnormal tendons in children: evaluation with ultrasound

Ultrasound (US) has emerged as an essential diagnostic tool for evaluating the entire musculoskeletal system in children. The spatial resolution of modern US technology offers unparalleled depiction of superficial anatomy, and motion and blood flow are demonstrated in real time allowing for the quick diagnosis of a wide variety of pathologies. US evaluation of tendons and their structure and function represents one of the best applications of musculoskeletal US. This article reviews some of the more common indications for US of the tendons in children. While not an exhaustive list, the anatomy and pathology examples described should help any pediatric radiologist confronted with a case of tendon pain or loss of function.

Acute Psoriatic Exacerbation Secondary to Infected Pacemaker With Staphylococcus aureus and Candida lusitaniae?

Psoriasis is a lifelong chronic hyperproliferative inflammatory immune-mediated disorder. There is a strong association of psoriasis exacerbation with infection of Staphylococcus and Streptococcus species. In the case of our patient, a psoriatic flare manifesting as dactylitis occurred secondary to methicillin sensitive Staphylococcus aureus bacteremia colonization of his pacemaker. If a patient is started on an antibiotic regimen, such as vancomycin, and has symptoms of rash, and swelling in the fingers, it is imperative to ask for a proper rheumatologic history, as vancomycin infusion reaction (previously known as Red Man Syndrome) may not be the cause of the flare-up, such as in the case of our patient. Inversely, patients with psoriasis are more likely to be colonized by S. aureus on the skin and in the nasal cavity, and this can lead to bacteremia and infection of hardware, such as an automatic implantable cardioverter-defibrillator (AICD).

How Variable Is the Volar Subcutaneous Tissue of the Digits on B-Mode and Color Doppler Ultrasound in Non-Psoriatic Individuals and Could It Be Included in a Dactylitis Score?

BACKGROUND

 Digital subcutaneous tissue (SCT) changes are involved in dactylitis, a hallmark feature of psoriatic arthritis (PsA). There are no studies on the ultrasound (US) characteristics of the digital SCT in the general population.

OBJECTIVES

 To investigate the variability in US-measured thickness (TH) and color Doppler (CD)-detected blood flow of the SCT of the volar aspects of the fingers in a non-psoriatic population and to investigate the impact of the scanning method and demographics and clinical features on these measurements.

METHODS

 SCT TH and semiquantitative (SQD) and quantitative (QD) Doppler signals were measured in the bilateral second finger at the proximal and middle phalanges in 81 non-psoriatic volunteers [49 female, 32 men; 18-78 years]. Two scanning methods with and without (thick gel layer interposition) probe-skin contact were used. Demographics and clinical features were collected.

RESULTS

 There was high variability of SCT TH and Doppler measurements between individuals. All US measurements obtained without probe-skin contact were significantly greater than their corresponding measurements obtained with the probe contacting the skin (p < 0.001). SCT TH was positively related to dominant hand, age, masculine gender, weight, height, body mass index, and alcohol consumption while Doppler measurements were positively related to age and non-dominant hand.

CONCLUSIONS

 US-measured SCT thickness and Doppler-detected SCT blood flow of the volar aspect of the fingers seem to be highly variable in the non-psoriatic population as well as highly dependent on the US scanning method. This variability is of utmost importance for assessing dactylitis in PsA.

Psoriatic Dactylitis: Current Perspectives and New Insights in Ultrasonography and Magnetic Resonance Imaging

Dactylitis, one of the most typical features of psoriatic arthritis (PsA), is the diffuse swelling of the digits and is determined by the involvement of different anatomic structures, including: the subcutaneous fibrous tissue “accessory pulley” system; flexor tendons, with their related structures; the articular synovium; the small enthesis of the hands. Dactylitis is currently considered both a marker of disease activity and severe prognosis and its importance in PsA is emphasized by the inclusion in the classification criteria of PsA. This review focuses on the role of imaging in the management of PsA patients with dactylitis in clinical practice and in a research setting. Furthermore, imaging could be a valuable tool to assist in unravelling some of the underlying mechanisms of the onset and chronicization of dactylitis in PsA patients.

Associations of ultrasound-based inflammation patterns with peripheral innate lymphoid cell populations, serum cytokines/chemokines, and treatment response to methotrexate in rheumatoid arthritis and spondyloarthritis

Objectives

We aimed to explore the associations of musculoskeletal inflammation patterns with peripheral blood innate lymphoid cell (ILC) populations, serum cytokines/chemokines, and treatment response to methotrexate in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA).

Methods

We enrolled 100 patients with either RA or SpA and performed ultrasound to evaluate power Doppler signals for synovitis (52 joint regions), tenosynovitis (20 tendons), and enthesitis (44 sites). We performed clustering analysis using unsupervised random forest based on the multi-axis ultrasound information and classified the patients into groups. We identified and counted ILC1-3 populations in the peripheral blood by flow cytometry and also measured the serum levels of 20 cytokines/chemokines. We also determined ACR20 response at 3 months in 38 patients who began treatment with methotrexate after study assessment.

Results

Synovitis was more prevalent and severe in RA than in SpA, whereas tenosynovitis and enthesitis were comparable between RA and SpA. Patients were classified into two groups which represented synovitis-dominant and synovitis-nondominant inflammation patterns. While peripheral ILC counts were not significantly different between RA and SpA, they were significantly higher in the synovitis-nondominant group than in the synovitis-dominant group (ILC1-3: p = 0.0007, p = 0.0061, and p = 0.0002, respectively). On the other hand, clustering of patients based on serum cytokines/chemokines did not clearly correspond either to clinical diagnoses or to synovitis-dominant/nondominant patterns. The synovitis-dominant pattern was the most significant factor that predicted clinical response to methotrexate (p = 0.0065).

Conclusions

Musculoskeletal inflammation patterns determined by ultrasound are associated with peripheral ILC counts and could predict treatment response to methotrexate.

Sensitivity to change and clinical correlations of the novel DACtylitis glObal Sonographic (DACTOS) score in psoriatic arthritis

OBJECTIVE

The aim of the study is to assess the performance of the DACTOS (DACtylitis glObal Sonographic) score in a PsA dactylitis clinical setting. In particular, we evaluated the ability of DACTOS to identify the affected fingers, its sensitivity to change after treatment, the correlations between DACTOS and clinical parameters, and the capacity of the score to identify the treatment responders.

METHODS

Forty-six consecutive patients with symptomatic PsA hand dactylitis were enrolled. A total of seventy-three dactylitic digits were evaluated clinically and sonographically before and after treatment in this observational and prospective study. Clinical assessment included the Leeds Dactylitis Index-basic (LDI-b) score and visual analogue scales for pain (VAS-p) and functional impairment (VAS-FI). Sonographic lesions were investigated using high-frequency ultrasound with grey scale and power Doppler features according to the DACTOS score. Correlations between the DACTOS score and the clinical parameters were assessed at baseline, 1 month (T1) and 3 months (T3).

RESULTS

We observed significant improvements in all of the assessed clinical parameters and the DACTOS scores after dactylitis treatment. There was a statistically significant correlation between the variation of all clinical parameters (VAS-p, VAS-FI and LDI-b) and the DACTOS score at T1 and T3 evaluations. We found statistically significant differences in the DACTOS score between clinical responder and non-responder groups (P < 0.001) and between clinical remission and non-remission groups (P < 0.001).

CONCLUSION

The DACTOS score performs well in real-life clinical settings in terms of sensitivity to change and correlations with clinical features in PsA dactylitis.

Which ultrasound lesions contribute to dactylitis in psoriatic arthritis and their reliability in a clinical setting

OBJECTIVES

To explore the frequency of ultrasound elementary lesions in dactylitis in psoriatic arthritis (PsA), and the reliability of scoring these lesions in a clinical setting.

METHODS

In 31 patients with PsA and clinical dactylitis, ultrasound assessment of the affected finger or toe was performed using greyscale and color Doppler mode. One examiner scanned all patients and a second examiner scanned 10 patients for inter-reader reliability. For each digit, the following lesions were evaluated: subcutaneous edema; soft tissue thickening; synovitis of the digital joints; tenosynovitis of the flexor tendon; enthesitis at the deep flexor tendon and the extensor tendon entheses; and paratenonitis of the extensor tendon. A dactylitis sum-score was calculated. Findings in clinically tender and non-tender digits were compared.

RESULTS

The most frequent lesions were soft tissue thickening (81%) and subcutaneous edema (74%) followed by synovitis (56-68%) and flexor tenosynovitis (52%). Color Doppler was most frequently found subcutaneously (55%) and around the flexor tendons (45%). All lesions were typically found in combinations, most commonly subcutaneous edema and synovitis (71%), subcutaneous edema and flexor tenosynovitis (52%), and all three in combination (52%). Tender digits had a higher dactylitis sum-score and numerically higher prevalence of most lesions than non-tender digits. Intra- and inter-reader agreements were moderate to excellent, though lower for few components of digital enthesitis, especially hypoechogenicity.

CONCLUSION

Dactylitis in PsA appears to encompass several lesions, most often subcutaneous changes combined with synovitis and/or flexor tenosynovitis. Reliability of scoring established ultrasound lesions of dactylitis in a clinical setting is moderate-excellent. Key Points • Dactylitis in psoriatic arthritis consists of multiple ultrasound lesions • A dactylitis ultrasound sum-score gives an impression of severity by including all lesions • Reliability of ultrasound scoring of dactylitis components is good.

Imaging in the diagnosis and management of peripheral psoriatic arthritis

Psoriatic arthritis is a heterogenous disease affecting peripheral and axial joints, tendons, ligaments, and their insertions, in addition to the skin and the nails. The complexity of the involved structures has puzzled clinicians trying to understand the underlying pathology that leads to symptoms in order to choose the appropriate medications with different modes of actions. Imaging, mainly ultrasound and magnetic resonance imaging, allows of accurate detection of inflammatory changes in the musculoskeletal structures, which helps to avoid false positive and negative assessments. The linking of different anatomical structures' involvement using imaging also provides insights into the pathogenesis of psoriatic arthritis. In this review, ultrasound and magnetic resonance imaging will be discussed in depth with regard to their use in the field of peripheral psoriatic arthritis, with a focus on the literature from the last 4 years and recent advances.

Novel and reliable DACTylitis glObal Sonographic (DACTOS) score in psoriatic arthritis

OBJECTIVES

Dactylitis is one of the most typical features of psoriatic arthritis (PsA), with a high lifetime prevalence and inclusion in PsA clinical indices. Musculoskeletal ultrasonography (Msk-US) can readily detect inflammatory involvement of finger anatomical structures particular to dactylitis and monitor therapeutic effects. In this study, we aim to identify the characteristic lesions in PsA dactylitis of the hands, assess the reliability of Msk-US in scoring those lesions and develop a DACTylitis glObal Sonographic (DACTOS) score.

METHODS

After a systematic literature review on the use of Msk-US in PsA dactylitis, 12 rheumatologists participated in a three-round Delphi procedure and consensus meeting to agree on the sonographic elementary lesions characterising dactylitis and on the composition of a global sonographic score. Then, a web-based and a patient-based intra-rater and inter-rater reliability exercise was performed to assess those lesions included in the score.

RESULTS

DACTOS score was obtained by summing the scores of each lesion selected in the Delphi survey: subcutaneous soft tissue oedema, flexor tenosynovitis, peritendon extensor inflammation and synovitis. The DACTOS score ranges from 0 to 25. In the reliability exercises, we obtained moderate-to-excellent agreement for the sonographic lesions included in the score.

CONCLUSIONS

The novel DACTOS score is a reliable measure to interpret the multiple characteristic sonographic features of dactylitis. The DACTOS score provides a useful global analysis of dactylitis of the hand and can represent a support to clinical diagnosis as well as a useful tool for the management and research in patients with PsA with dactylitis.

The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review

Early differentiation between different types of inflammatory arthritis and subsequent initiation of modern treatments can improve patient outcomes by reducing disease activity and preventing joint damage. Routine clinical evaluation, laboratory testing, and radiographs are typically sufficient for differentiating between inflammatory and predominantly degenerative arthritis (e.g., osteoarthritis). However, in some patients with inflammatory arthritis, these techniques fail to accurately identify the type of early-stage disease. Further evaluation by ultrasound imaging can delineate the inflammatory arthritis phenotype present. Ultrasound is a noninvasive, cost-effective method that enables the evaluation of several joints at the same time, including functional assessments. Further, ultrasound can visualize pathophysiological changes such as synovitis, tenosynovitis, enthesitis, bone erosions, and crystal deposits at a subclinical level, which makes it an effective technique to identify and differentiate most common types of inflammatory arthritis. Limitations associated with ultrasound imaging should be considered for its use in the differentiation and diagnosis of inflammatory arthritides.

Comparing Psoriatic Arthritis Low-field Magnetic Resonance Imaging, Ultrasound, and Clinical Outcomes: Data from the TICOPA Trial

Objective.

The Tight Control of inflammation in Psoriatic arthritis (TICOPA; isrctn.com: ISRCTN30147736) trial compared standard care (StdC) and tight control (TC) in early psoriatic arthritis (PsA), demonstrating better outcomes for TC. This substudy evaluated the performance metrics of modern imaging outcomes and compared them to the clinical data.

Methods.

Non-contrast 0.2T magnetic resonance imaging (MRI; single hand) was assessed using the Outcomes in Rheumatology (OMERACT) PsA MRI Scoring System (PsAMRIS) with an additional global inflammation score. Ultrasound (US; same hand) was scored for greyscale, power Doppler, and erosions at the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints and scores summated.

Results.

Seventy-eight patients had paired (baseline and 48 weeks) US data and 61 paired MRI data; 50 had matched clinical, MR, and US data. Significant within-group changes were seen for the inflammatory PsAMRIS components at MCP level: MRI global inflammation [median difference (range), standardized response mean (SRM)]: 3.25 (−5.0 to 12.0), 0.68; 1.0 (−4.5 to 17.5), 0.45 for TC and StdC, respectively. Similar within-group differences were obtained for US: 1.0 (−13.0 to 23.0), 0.45; 3.0 (−6.0 to 21.0), 0.77 for TC and StdC, respectively. No differences were seen between treatment groups. Significant correlations were found between baseline and change MRI and US scores. A significant correlation was found between baseline PsA disease activity scores and MRI global inflammation scores (Spearman ρ for MCP, PIP: 0.46, 0.63, respectively). No differences in erosion progression were observed.

Conclusion.

The PsAMRIS and US inflammation scores demonstrated good responsiveness. No between-group differences were demonstrated, but this substudy was likely underpowered to determine differences between the 2 treatment strategies.

Diagnostic efficacy of ultrasound detection of enthesitis in peripheral spondyloarthritis

Objective: We investigated the diagnostic efficacy of power Doppler ultrasound (PDUS) to detect enthesitis in Japanese patients with peripheral spondyloarthritis (SpA).Methods: This was a single-center cohort study of patients with peripheral symptoms suggestive of SpA. Articular synovia, tendons, and entheses were assessed by PDUS at baseline. Clinical, laboratory, and radiologic findings and classification criteria for SpA were also evaluated.Results: 136 patients were consecutively evaluated. A definite diagnosis was obtained in 111 patients, including 72 with SpA and 39 non-SpA. Among the patients with SpA, PDUS demonstrated articular synovitis in 40 of the 72 patients (56%), tenosynovitis or peritendinitis in 48 (67%), and enthesitis in 63 (88%). Considering PDUS alone, enthesitis in at least one site was the most useful means of differentiating SpA from non-SpA (sensitivity 87.5%; specificity 82.1%; accuracy 85.6%; positive likelihood ratio 4.88). Combining that finding along with fulfillment of Amor, European Spondyloarthropathy Study Group, or Assessment of SpondyloArthritis international Society criteria for peripheral SpA increased the specificity of the diagnosis (92.5%, 92.3%, and 97.4%, respectively).Conclusion: PDUS enthesitis is useful for the diagnosis of SpA with peripheral symptoms. Combining PDUS enthesitis with established SpA classification criteria is beneficial in diagnosing peripheral SpA.

Characteristics of late-onset spondyloarthritis in Japan: A retrospective cohort study

Spondyloarthritis may be increasingly present in older patients as life expectancy increases. We investigated clinical differences between early-onset and late-onset spondyloarthritis in Japan.We retrospectively reviewed 114 patients consecutively diagnosed with spondyloarthritis. The clinical course of each patient was observed for ≥1 year. We defined early-onset and late-onset spondyloarthritis as <57 or ≥57 years at a median age of this study group, respectively. We compared clinical characteristics between these 2 groups.Disease duration was significantly shorter before diagnosis in the late-onset group (P < .01). Inflammatory back pain (IBP) was significantly more common in the early-onset group (P < .01), whereas dactylitis frequency was significantly higher in the late-onset group. Significantly more patients with early-onset spondyloarthritis were human leukocyte antigen (HLA) B27-positive (P < .01). Articular synovitis, particularly of the wrist, was significantly more common on power Doppler ultrasound (PDUS) in the late-onset group (P < .01). Tenosynovitis or peritendinitis, particularly in the finger and wrist flexors were also more frequent in the late-onset group (P < .001 and P < .05, respectively). Enthesitis of the finger collateral ligament and lateral collateral ligament were significantly more common in the late-onset group (both P < .05). Multiple logistic regression analysis revealed that, comparatively, IBP was significantly and independently much more likely to occur in the early-onset group.The patients with late-onset spondyloarthritis had a lower frequency of IBP and HLA B27 and a higher frequency of dactylitis and PDUS findings in peripheral involvement.

Symptomatic psoriatic dactylitis is associated with ultrasound determined extra-synovial inflammatory features and shorter disease duration

OBJECTIVES

To explore the link between ultrasonographic features of dactylitis in psoriatic arthritis (PsA) and symptoms, digital tenderness and duration of dactylitis.

METHODS

Forty-eight cases of PsA dactylitis were investigated using high frequency ultrasound (US) both in grey scale (GS) and Power Doppler (PD), evaluating the presence and the degree of flexor tenosynovitis, peri-tendinous oedema, subcutaneous PD, extensor tendon involvement, GS synovitis and intra-articular PD signal (PDS) of the involved digits. Patients were compared according to the presence of local pain and digital tenderness, the duration of dactylitis and the concomitant treatment.

RESULTS

The presence of pain/tenderness was positively associated with US GS flexor tenosynovitis of grade > 2 (p < 0.001), PD-flexor tenosynovitis (p < 0.001), peri-tendinous oedema (p < 0.001) and subcutaneous PDS (p < 0.001); moreover, it was negatively associated with GS synovitis (p < 0.001) and intra-articular PD (p < 0.001). The same positive and negative association with US findings were found comparing patients with duration of dactylitis shorter or longer than the median (24 weeks) (p < 0.001 for all comparisons).

CONCLUSIONS

Pain and digital tenderness are linked to dactylitis duration and earlier lesions are associated with extra synovial inflammatory changes. These findings suggest a hitherto unappreciated extra synovial basis for symptoms in PsA dactylitis.

Enthesitis and Dactylitis in Psoriatic Disease: A Guide for Dermatologists

Psoriatic arthritis (PsA) is an inflammatory arthritis that is estimated to affect approximately 30% of patients with psoriasis. Enthesitis and dactylitis, two hallmarks of PsA, are associated with radiographic peripheral/axial joint damage and severe disease. Clinical symptoms of enthesitis include tenderness, soreness, and pain at entheses on palpation, whereas dactylitis is recognized by swelling of an entire digit that is different from adjacent digits. Both ultrasound and magnetic resonance imaging can be used to diagnose enthesitis and dactylitis, especially in patients in whom symptoms may be difficult to discern. Delayed treatment of PsA can result in irreversible joint damage and reduced quality of life. Thus, it is recommended that dermatologists monitor patients with psoriasis for these two early and important manifestations of PsA.

Sonography of Non-neoplastic Disorders of the Hand and Wrist Tendons

Tendon disorders commonly cause hand and wrist disability and curtail the performance of work-related duties or routine tasks. Imaging is often needed for diagnosis, but it requires knowledge of the complex anatomic structures of the tendons of the hand and wrist as well as familiarity with related disorders. This review article aims to provide medical professionals with guidelines for the sonographic assessment of the tendons of hand and wrist and related disorders. Sonographic features of tendon disorders affecting the hand and wrist are described here, specifically: infectious tenosynovitis; tendon rupture or tearing; stenosing forms of tenosynovitis such as De Quervain disease and trigger finger; intersection syndrome; insertional tendinopathy; several forms of tendinous instability such as extensor carpi ulnaris instability, climber finger, and boxer knuckle; and tendinopathy in inflammatory rheumatic diseases. Postsurgical evaluation of the hand and wrist tendons is also discussed, including the healthy and pathologic appearances of operated tendons as well as impingement from orthopedic hardware. In conclusion, sonography is effective in assessing the tendons of the hand and wrist and related disorders and represents a valuable tool for diagnosis.

Musculoskeletal ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review

Objective

To systematically review the role of musculoskeletal US in patients suffering from PsA or psoriasis (Pso) in terms of prevalence, diagnosis, prognosis, monitoring and treatment.

Methods

A systematic literature review was conducted through medical databases (MEDLINE via PubMed, Embase) and the grey literature up to September 2015 to inform a new study of the Musculoskeletal Ultrasound Study Group of the Italian Society for Rheumatology. All articles reporting data on musculoskeletal US in PsA or Pso were included and extracted according to the underlying clinical question.

Results

A total of 86 publications were included. The prevalence of US abnormalities showed a wide range for each examined feature (e.g. 37-95% for entheses thickness of the lower limbs). The performance of US for diagnosis of disease or elementary lesions was variable across studies, but no study evaluated the overall performance of US in addition to clinical findings for diagnosing PsA. Considering US in defining PsA and Pso prognosis, several works focused on US of entheses of lower limbs in Pso, while for the monitoring of PsA activity five different scoring systems were identified. Last, the results of the role of US in guiding intra-articular interventions were controversial for the clinical outcomes, but in favour of US for accuracy.

Conclusion

despite the recognized importance of US in the management of PsA and Pso, this review clearly demonstrated the need of pivotal research in order to optimize the use of US in the diagnosis and monitoring of psoriatic disease.

Adult Inflammatory Arthritides: What the Radiologist Should Know

Developments and improvements in knowledge are rapid and ongoing in both the radiologic and rheumatologic fields. During the past decade, the roles of imaging and the radiologist in the assessment and management of many inflammatory rheumatologic diseases have undergone several changes. To remain effective in patient care, the radiologist needs to be aware of these changes when recommending and interpreting imaging examinations for the referring physician. The goal of contemporary rheumatoid arthritis (RA) management is to redefine RA as a disease that is no longer characterized by erosions, which reflect established or long-standing untreated disease. Most cases of RA are now diagnosed clinically, but imaging increases diagnostic confidence, is superior to clinical examination for the detection of joint inflammation, and plays an important role in patient management. The concept of the seronegative spondyloarthritides has recently been redefined by the Assessment of SpondyloArthritis International Society (ASAS). This new set of ASAS classification criteria divides the spectrum of spondyloarthritis on the basis of predominantly axial skeletal clinical manifestations or predominantly peripheral skeletal clinical manifestations. For axial spondyloarthritis, magnetic resonance imaging and radiography play crucial roles for classification and diagnosis. For both peripheral spondyloarthritis and psoriatic arthritis, the radiologist can provide important information that influences classification and diagnosis, including documenting radiologic evidence of juxta-articular new bone formation, diagnosing sacroiliitis, or delineating the presence and extent of enthesitis and dactylitis. The radiologist's familiarity with recent classification criteria, in addition to the traditional diagnostic characteristics of the individual inflammatory arthritides, maximizes the productive interface between the radiologist and the rheumatologist. ^©RSNA, 2016.

The spectrum of psoriatic arthritis in a South African cohort

The aim of this study was to describe the clinical features of patients with psoriatic arthritis (PsA) in a South African cohort. This is a retrospective analysis of patients contributing to development of the international classification criteria for PsA, ClASsification criteria for Psoriatic ARthritis (CASPAR). Patients were all seen at the arthritis clinics at Groote Schuur Hospital, Cape Town. Demographic, clinical, laboratory and radiographic information was collected. This study describes the relevant findings relating to the clinical profile of the patients seen at our centre as well as the effect of family history and/or dactylitis in determining the severity of psoriatic arthritis. There were 45 patients with a male to female ratio of 1:1.25. The mean age of psoriasis onset was 38.34 years (SD 15.54), whilst that of arthritis onset was 43.86 years (SD 13.4). Polyarthritis was the commonest pattern and sacro-iliitis was uncommon. Dactylitis was present in 26%. The presence of family history or of dactylitis did not predict more severe disease. There was a significant correlation between tender and swollen joints. The mean Health Assessment Questionnaire (HAQ) score was 1.05. Eighty-three percent showed evidence of radiological changes, and distal interphalangeal (DIP) erosions were found in 54%. Arthritis mutilans was present in 31%. There were no black subjects in the cohort. The clinical patterns of PsA in our cohort are similar to those reported elsewhere. The paucity of blacks amongst this cohort requires further study. PsA-specific measures of disease activity need to be developed. PsA causes significant joint damage and disability.

Beyond the Bowel: Extraintestinal Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic, relapsing immune-mediated inflammation of the gastrointestinal tract. IBD includes two major disease entities: Crohn disease and ulcerative colitis. Imaging plays an important role in the diagnosis and surveillance of these complex disorders. Computed tomographic and magnetic resonance enterographic techniques have been refined in recent years to provide a superb means of evaluating the gastrointestinal tract for suspected IBD. Although the intestinal imaging manifestations of IBD have been extensively discussed in the radiology literature, extraintestinal imaging manifestations of IBD have received less attention. Multiple extraintestinal manifestations may be seen in IBD, including those of gastrointestinal (hepatobiliary and pancreatic), genitourinary, musculoskeletal, pulmonary, cardiac, ocular, and dermatologic disorders. Although many associations between IBD and extraintestinal organ systems have been well established, other associations have not been fully elucidated. Some extraintestinal disorders may share a common pathogenesis with IBD. Other extraintestinal disorders may occur as a result of unintended treatment-related complications of IBD. Although extraintestinal disorders within the abdomen and pelvis may be well depicted with cross-sectional enterography, other musculoskeletal and thoracic disorders may be less evident with such examinations and may warrant further investigation with additional imaging examinations or may be readily apparent from the findings at physical examination. Radiologists involved in the interpretation of IBD imaging examinations must be aware of potential extraintestinal manifestations, to provide referring clinicians with an accurate and comprehensive profile of patients with these complex disorders. ^© RSNA, 2017.

Recommendations for the Use of Ultrasound and Magnetic Resonance in Patients With Spondyloarthritis, Including Psoriatic Arthritis, and Patients With Juvenile Idiopathic Arthritis

OBJECTIVE

To develop evidence-based recommendations on the use of ultrasound (US) and magnetic resonance imaging in patients with spondyloarthritis, including psoriatic arthritis, and juvenile idiopathic arthritis.

METHODS

Recommendations were generated following a nominal group technique. A panel of experts (15 rheumatologists and 3 radiologists) was established in the first panel meeting to define the scope and purpose of the consensus document, as well as chapters, potential recommendations and systematic literature reviews (we used and updated those from previous EULAR documents). A first draft of recommendations and text was generated. Then, an electronic Delphi process (2 rounds) was carried out. Recommendations were voted from 1 (total disagreement) to 10 (total agreement). We defined agreement if at least 70% of participants voted≥7. The level of evidence and grade or recommendation was assessed using the Oxford Centre for Evidence Based Medicine levels of evidence. The full text was circulated and reviewed by the panel. The consensus was coordinated by an expert methodologist.

RESULTS

A total of 12 recommendations were proposed for each disease. They include, along with explanations of the validity of US and magnetic resonance imaging regarding inflammation and damage detection, diagnosis, prediction (structural damage progression, flare, treatment response, etc.), monitoring and the use of US guided injections/biopsies.

CONCLUSIONS

These recommendations will help clinicians use US and magnetic resonance imaging in patients with spondyloarthritis and juvenile idiopathic arthritis.

High-Resolution US of Rheumatologic Diseases

For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

[Treat-to-target (T2T) recommendation for patients with spondyloarthritis - translation into German]

The management of patients with spondyloarthritis (SpA) has experienced a paradigm shift in recent years. This is true for the treatment of axial as well as peripheral manifestations. International treat to target (T2T) recommendations for SpA based on the T2T strategy have now also been published, which contain 5 higher level principles (A-E) in addition to the 15 recommendations. In order to make the recommendations known and to promote national distribution, German experts have now issued a translation of the T2T recommendations for SpA into German.

Proceedings from The 8th Annual International Society for Musculoskeletal Imaging in Rheumatology (ISEMIR) Conference

The International Society for Musculoskeletal Imaging in Rheumatology (ISEMIR) was founded in 2005 with the goal of discussing matters related to imaging in rheumatology, particularly, validation, education, and use in both clinical practice and research. The field of musculoskeletal (MSK) imaging is continuously evolving; therefore, education for healthcare providers in this field is of paramount importance. ISEMIR's international faculty and world-renowned experts presented the newest information as it relates to the use of magnetic resonance imaging (MRI) and ultrasound (US) at the 8th annual ISEMIR meeting that took place on April 17-18 in Santa Monica, California. Presentations from the meeting can be viewed at www.isemir.org.

Management of Musculoskeletal Manifestations in Inflammatory Bowel Disease

Musculoskeletal manifestations are the most common extraintestinal manifestations in inflammatory bowel diseases. Some appendicular manifestations are independent of gut inflammation and are treated with standard anti-inflammatory strategies. On the other hand, axial involvement is linked to gut inflammatory activity; hence, there is a considerable amount of treatment overlap. Biological therapies have revolutionized management of inflammatory bowel diseases as well as of associated articular manifestations. Newer mechanisms driving gut associated arthropathy have surfaced in the past decade and have enhanced our interests in novel treatment targets. Introduction of biosimilar molecules is expected in the US market in the near future and will provide an opportunity for considerable cost savings on healthcare. A multidisciplinary approach involving a gastroenterologist, rheumatologist, and physical therapist is ideal for these patients.

Concepts of pathogenesis in psoriatic arthritis: genotype determines clinical phenotype

This review focuses on the genetic features of psoriatic arthritis (PsA) and their relationship to phenotypic heterogeneity in the disease, and addresses three questions: what do the recent studies on human leukocyte antigen (HLA) tell us about the genetic relationship between cutaneous psoriasis (PsO) and PsA – that is, is PsO a unitary phenotype; is PsA a genetically heterogeneous or homogeneous entity; and do the genetic factors implicated in determining susceptibility to PsA predict clinical phenotype? We first discuss the results from comparing the HLA typing of two PsO cohorts: one cohort providing the dermatologic perspective, consisting of patients with PsO without evidence of arthritic disease; and the second cohort providing the rheumatologic perspective, consisting of patients with PsA. We show that these two cohorts differ considerably in their predominant HLA alleles, indicating the heterogeneity of the overall PsO phenotype. Moreover, the genotype of patients in the PsA cohort was shown to be heterogeneous with significant elevations in the frequency of haplotypes containing HLA-B*08, HLA-C*06:02, HLA-B*27, HLA-B*38 and HLA-B*39. Because different genetic susceptibility genes imply different disease mechanisms, and possibly different clinical courses and therapeutic responses, we then review the evidence for a phenotypic difference among patients with PsA who have inherited different HLA alleles. We provide evidence that different alleles and, more importantly, different haplotypes implicated in determining PsA susceptibility are associated with different phenotypic characteristics that appear to be subphenotypes. The implication of these findings for the overall pathophysiologic mechanisms involved in PsA is discussed with specific reference to their bearing on the discussion of whether PsA is conceptualised as an autoimmune process or one that is based on entheseal responses.

The OMERACT Ultrasound Working Group 10 Years On: Update at OMERACT 12

Musculoskeletal ultrasound (US) now thrives as an established imaging modality for the investigation and management of chronic inflammatory arthritis. We summarize here results of the Outcome Measures in Rheumatology (OMERACT) US working group (WG) projects of the last 2 years. These results were reported at the OMERACT 12 meeting at the plenary session and discussed during breakout sessions. Topics included standardization of US use in rheumatic disease over the last decade and its contribution to understanding musculoskeletal diseases. This is the first update report of WG activities in validating US as an outcome measure in musculoskeletal inflammatory and degenerative diseases, including pediatric arthritis, since the OMERACT 11 meeting.

Novel imaging modalities in spondyloarthritis

Novel imaging techniques have emerged in the field of spondyloarthritis. This article will cover the role of, and the sensitivity and specificity of magnetic resonance imaging (MRI) and ultrasound in the diagnosis and monitoring of axial and peripheral SpA. It will discuss how the definition of a 'positive MRI' of the sacroiliac joints and spine is evolving. Differential diagnoses of inflammatory lesions of both the sacroiliac joints and the spine are addressed due to their importance in image interpretation. The article will also discuss the role of sonography in assessing peripheral entheses, joints, tendon sheaths, nails and soft tissues. The utility for clinical as well as an outcome measure will be discussed. We finally aim to give guidance on when and how to use these new modalities and on how to analyse and interpret the imaging findings in daily practice.

Comprehensive Treatment of Dactylitis in Psoriatic Arthritis

Dactylitis, a hallmark clinical feature of psoriatic arthritis (PsA) and other spondyloarthropathies, may also be a severity marker for PsA and psoriasis. Traditionally, clinicians have used nonsteroidal antiinflammatory drugs and local corticosteroid injections to treat dactylitis, although conventional disease-modifying antirheumatic drugs are also used. We performed a systematic literature review to determine the most efficacious current treatment options for dactylitis in PsA. Effect sizes were greatest for the biologic agents ustekinumab, certolizumab, and infliximab, suggesting that therapy with one of these agents should be initiated in patients with dactylitis. However, the limited data highlight the need for randomized, placebo-controlled trials, with dactylitis as a primary outcome, to determine a valid, reliable, and responsive clinical outcome measure for PsA patients with dactylitis.

Ultrasound composite scores for the assessment of inflammatory and structural pathologies in Psoriatic Arthritis (PsASon-Score)

Introduction

This study was performed to develop ultrasound composite scores for the assessment of inflammatory and structural lesions in Psoriatic Arthritis (PsA).

Methods

We performed a prospective study on 83 PsA patients undergoing two study visits scheduled 6 months apart. B-mode and Power Doppler (PD) findings were semi-quantitatively scored at 68 joints (evaluating synovia, perisynovial tissue, tendons and bone) and 14 entheses. We constructed bilateral and unilateral (focusing the dominant site) ultrasound composite scores selecting relevant sites by a hierarchical approach. We tested convergent construct validity, reliability and feasibility of inflammatory and structural elements of the scores as well as sensitivity to change for inflammatory items.

Results

The bilateral score (termed PsASon22) included 22 joints (6 metacarpophalangeal joints (MCPs), 4 proximal interphalangeal joints (PIPs) of hands (H-PIPs), 2 metatarsophalangeal joints (MTPs), 4 distal interphalangeal joints (DIPs) of hands (H-DIPs), 2 DIPs of feet (F-DIPs), 4 large joints) and 4 entheses (bilateral assessment of lateral epicondyle and distal patellar tendon). The unilateral score (PsASon13) compromised 13 joints (2 MCPs, 3 H-PIPs, 1 PIP of feet (F-PIP), 2 MTPs, 1 H-DIP and 2 F-DIPs and 2 large joints) and 2 entheses (unilateral lateral epicondyle and distal patellar tendon). Both composite scores revealed a moderate to high sensitivity (bilateral composite score 43% to 100%, unilateral 36% to 100%) to detect inflammatory and structural lesions compared to the 68-joint/14-entheses score. The inflammatory and structural components of the composite scores correlated weakly with clinical markers of disease activity (corr_coeffs 0 to 0.40) and the health assessment questionnaire (HAQ, corr_coeffs 0 to 0.39), respectively. Patients with active disease achieving remission at follow-up yielded greater reductions of ultrasound inflammatory scores than those with stable clinical activity (Cohen’s d effect size ranging from 0 to 0.79). Inter-rater reliability of bi- and unilateral composite scores was moderate to good with ICCs ranging from 0.42 to 0.96 and from 0.36 to 0.71, respectively for inflammatory and structural sub-scores. The PsASon22 and PsASon13 required 16 to 26 and 9 to 13 minutes, respectively to be completed.

Conclusion

Both new PsA ultrasound composite scores (PsASon22 and PsASon13) revealed sufficient convergent construct validity, sensitivity to change, reliability and feasibility.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-014-0476-2) contains supplementary material, which is available to authorized users.