Definitions and reliability assessment of elementary ultrasound lesions in giant cell arteritis: a study from the OMERACT Large Vessel Vasculitis Ultrasound Working Group

Objectives

To define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise.

Methods

Potential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise.

Results

Twenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The ‘halo’ and ‘compression’ signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the ‘halo’ sign and the ‘compression’ sign was excellent with inter-rater agreements of 91–99% and mean kappa values of 0.83–0.98 for both inter-rater and intra-rater reliabilities of all 25 experts.

Conclusions

The ‘halo’ and the ‘compression’ signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent.

Identification of calcium pyrophosphate deposition disease (CPPD) by ultrasound: reliability of the OMERACT definitions in an extended set of joints-an international multiobserver study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force

OBJECTIVES

To assess the reliability of the OMERACT ultrasound (US) definitions for the identification of calcium pyrophosphate deposition disease (CPPD) at the metacarpal-phalangeal, triangular fibrocartilage of the wrist (TFC), acromioclavicular (AC) and hip joints.

METHODS

A web-based exercise and subsequent patient-based exercise were carried out. A panel of 30 OMERACT members, participated at the web-based exercise by evaluating twice a set of US images for the presence/absence of CPPD. Afterwards, 19 members of the panel met in Siena, Italy, for the patient-based exercise. During the exercise, all sonographers examined twice eight patients for the presence/absence of CPPD at the same joints. Intraoberserver and interobserver kappa values were calculated for both exercises.

RESULTS

The web-based exercise yielded high kappa values both in intraobserver and interobserver evaluation for all sites, while in the patient-based exercise, inter-reader agreement was acceptable for the TFC and the AC. TFC reached high interobserver and intraobserver k values in both exercises, ranging from 0.75 to 0.87 (good to excellent agreement). AC reached moderate kappa values, from 0.51 to 0.85 (moderate to excellent agreement) and can readily be used for US CPPD identification.

CONCLUSIONS

Based on the results of our exercise, the OMERACT US definitions for the identification of CPPD demonstrated to be reliable when applied to the TFC and AC. Other sites reached good kappa values in the web-based exercise but failed to achieve good reproducibility at the patient-based exercise, meaning the scanning method must be further refined.

The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study

BACKGROUND

Giant cell arteritis (GCA) is a relatively common form of primary systemic vasculitis, which, if left untreated, can lead to permanent sight loss. We compared ultrasound as an alternative diagnostic test with temporal artery biopsy, which may be negative in 9-61% of true cases.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of ultrasound with biopsy in diagnosing patients with suspected GCA.

DESIGN

Prospective multicentre cohort study.

SETTING

Secondary care.

PARTICIPANTS

A total of 381 patients referred with newly suspected GCA.

MAIN OUTCOME MEASURES

Sensitivity, specificity and cost-effectiveness of ultrasound compared with biopsy or ultrasound combined with biopsy for diagnosing GCA and interobserver reliability in interpreting scan or biopsy findings.

RESULTS

We developed and implemented an ultrasound training programme for diagnosing suspected GCA. We recruited 430 patients with suspected GCA. We analysed 381 patients who underwent both ultrasound and biopsy within 10 days of starting treatment for suspected GCA and who attended a follow-up assessment (median age 71.1 years; 72% female). The sensitivity of biopsy was 39% [95% confidence interval (CI) 33% to 46%], which was significantly lower than previously reported and inferior to ultrasound (54%, 95% CI 48% to 60%); the specificity of biopsy (100%, 95% CI 97% to 100%) was superior to ultrasound (81%, 95% CI 73% to 88%). If we scanned all suspected patients and performed biopsies only on negative cases, sensitivity increased to 65% and specificity was maintained at 81%, reducing the need for biopsies by 43%. Strategies combining clinical judgement (clinician's assessment at 2 weeks) with the tests showed sensitivity and specificity of 91% and 81%, respectively, for biopsy and 93% and 77%, respectively, for ultrasound; cost-effectiveness (incremental net monetary benefit) was £485 per patient in favour of ultrasound with both cost savings and a small health gain. Inter-rater analysis revealed moderate agreement among sonographers (intraclass correlation coefficient 0.61, 95% CI 0.48 to 0.75), similar to pathologists (0.62, 95% CI 0.49 to 0.76).

LIMITATIONS

There is no independent gold standard diagnosis for GCA. The reference diagnosis used to determine accuracy was based on classification criteria for GCA that include clinical features at presentation and biopsy results.

CONCLUSION

We have demonstrated the feasibility of providing training in ultrasound for the diagnosis of GCA. Our results indicate better sensitivity but poorer specificity of ultrasound compared with biopsy and suggest some scope for reducing the role of biopsy. The moderate interobserver agreement for both ultrasound and biopsy indicates scope for improving assessment and reporting of test results and challenges the assumption that a positive biopsy always represents GCA.

FUTURE WORK

Further research should address the issue of an independent reference diagnosis, standards for interpreting and reporting test results and the evaluation of ultrasound training, and should also explore the acceptability of these new diagnostic strategies in GCA.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice

To develop evidence-based recommendations for the use of imaging modalities in primary large vessel vasculitis (LVV) including giant cell arteritis (GCA) and Takayasu arteritis (TAK). European League Against Rheumatism (EULAR) standardised operating procedures were followed. A systematic literature review was conducted to retrieve data on the role of imaging modalities including ultrasound, MRI, CT and [18F]-fluorodeoxyglucose positron emission tomography (PET) in LVV. Based on evidence and expert opinion, the task force consisting of 20 physicians, healthcare professionals and patients from 10 EULAR countries developed recommendations, with consensus obtained through voting. The final level of agreement was voted anonymously. A total of 12 recommendations have been formulated. The task force recommends an early imaging test in patients with suspected LVV, with ultrasound and MRI being the first choices in GCA and TAK, respectively. CT or PET may be used alternatively. In case the diagnosis is still in question after clinical examination and imaging, additional investigations including temporal artery biopsy and/or additional imaging are required. In patients with a suspected flare, imaging might help to better assess disease activity. The frequency and choice of imaging modalities for long-term monitoring of structural damage remains an individual decision; close monitoring for aortic aneurysms should be conducted in patients at risk for this complication. All imaging should be performed by a trained specialist using appropriate operational procedures and settings. These are the first EULAR recommendations providing up-to-date guidance for the role of imaging in the diagnosis and monitoring of patients with (suspected) LVV.

Ultrasound cut-off values for intima-media thickness of temporal, facial and axillary arteries in giant cell arteritis

Objective

To evaluate the intima-media thickness (IMT) of arteries involved in GCA for determining cut-off values.

Methods

Forty newly diagnosed GCA patients in a fast-track GCA clinic and 40 age- and sex-matched controls were included. IMT measurement was performed at or within 24 h after diagnosis. The common superficial temporal arteries with their frontal and parietal branches and the facial arteries were bilaterally examined with a 10-22 MHz probe and the axillary artery with a 6-18 MHz probe. Receiver operating characteristics analysis was performed for estimating cut-off values.

Results

The mean age was 72 years (s.d. 9) and 68% were females. In the control group, IMT was 0.23 mm (s.d. 0.04), 0.19 mm (s.d. 0.03), 0.20 mm (s.d. 0.03), 0.24 mm (s.d. 0.05) and 0.59 mm (s.d. 0.10) for the common superficial temporal arteries, the frontal and parietal branches, the facial arteries and the axillary arteries, respectively. In vasculitic segments of GCA patients, IMT was 0.65 mm (s.d. 0.18), 0.54 mm (s.d. 0.18), 0.50 mm (s.d. 0.17), 0.53 mm (s.d. 0.16) and 1.7 mm (s.d. 0.41), respectively. Cut-off values are 0.42, 0.34, 0.29, 0.37 and 1.0 mm, respectively, with 100% sensitivities and specificities for common superficial temporal arteries, for frontal branches and for axillary arteries and sensitivities of 97.2 and 87.5% and specificities of 98.7 and 98.8% for parietal branches and facial arteries, respectively. The intraclass correlation coefficient was between 0.87 and 0.98.

Conclusion

IMT measurement can correctly distinguish vasculitic from normal arteries in suspected GCA.

The 2017 EULAR standardised procedures for ultrasound imaging in rheumatology

BACKGROUND

In 2001, the European League Against Rheumatism developed and disseminated the first guidelines for musculoskeletal (MS) ultrasound (US) in rheumatology. Fifteen years later, the dramatic expansion of new data on MSUS in the literature coupled with technological developments in US imaging has necessitated an update of these guidelines.

OBJECTIVES

To update the existing MSUS guidelines in rheumatology as well as to extend their scope to other anatomic structures relevant for rheumatology.

METHODS

The project consisted of the following steps: (1) a systematic literature review of MSUS evaluable structures; (2) a Delphi survey among rheumatologist and radiologist experts in MSUS to select MS and non-MS anatomic structures evaluable by US that are relevant to rheumatology, to select abnormalities evaluable by US and to prioritise these pathologies for rheumatology and (3) a nominal group technique to achieve consensus on the US scanning procedures and to produce an electronic illustrated manual (ie, App of these procedures).

RESULTS

Structures from nine MS and non-MS areas (ie, shoulder, elbow, wrist and hand, hip, knee, ankle and foot, peripheral nerves, salivary glands and vessels) were selected for MSUS in rheumatic and musculoskeletal diseases (RMD) and their detailed scanning procedures (ie, patient position, probe placement, scanning method and bony/other landmarks) were used to produce the App. In addition, US evaluable abnormalities present in RMD for each anatomic structure and their relevance for rheumatology were agreed on by the MSUS experts.

CONCLUSIONS

This task force has produced a consensus-based comprehensive and practical framework on standardised procedures for MSUS imaging in rheumatology.

Settings and artefacts relevant for Doppler ultrasound in large vessel vasculitis

Ultrasound is used increasingly for diagnosing large vessel vasculitis (LVV). The application of Doppler in LVV is very different from in arthritic conditions. This paper aims to explain the most important Doppler parameters, including spectral Doppler, and how the settings differ from those used in arthritic conditions and provide recommendations for optimal adjustments. This is addressed through relevant Doppler physics, focusing, for example, on the Doppler shift equation and how angle correction ensures correctly displayed blood velocity. Recommendations for optimal settings are given, focusing especially on pulse repetition frequency (PRF), gain and Doppler frequency and how they impact on detection of flow. Doppler artefacts are inherent and may be affected by the adjustment of settings. The most important artefacts to be aware of, and to be able to eliminate or minimize, are random noise and blooming, aliasing and motion artefacts. Random noise and blooming artefacts can be eliminated by lowering the Doppler gain. Aliasing and motion artefacts occur when the PRF is set too low, and correct adjustment of the PRF is crucial. Some artefacts, like mirror and reverberation artefacts, cannot be eliminated and should therefore be recognised when they occur. The commonly encountered artefacts, their importance for image interpretation and how to adjust Doppler setting in order to eliminate or minimize them are explained thoroughly with imaging examples in this review.

Scoring ultrasound synovitis in rheumatoid arthritis: a EULAR-OMERACT ultrasound taskforce-Part 2: reliability and application to multiple joints of a standardised consensus-based scoring system

Objectives

To test the reliability of new ultrasound (US) definitions and quantification of synovial hypertrophy (SH) and power Doppler (PD) signal, separately and in combination, in a range of joints in patients with rheumatoid arthritis (RA) using the European League Against Rheumatisms–Outcomes Measures in Rheumatology (EULAR-OMERACT) combined score for PD and SH.

Methods

A stepwise approach was used: (1) scoring static images of metacarpophalangeal (MCP) joints in a web-based exercise and subsequently when scanning patients; (2) scoring static images of wrist, proximal interphalangeal joints, knee and metatarsophalangeal joints in a web-based exercise and subsequently when scanning patients using different acquisitions (standardised vs usual practice). For reliability, kappa coefficients (κ) were used.

Results

Scoring MCP joints in static images showed substantial intraobserver variability but good to excellent interobserver reliability. In patients, intraobserver reliability was the same for the two acquisition methods. Interobserver reliability for SH (κ=0.87) and PD (κ=0.79) and the EULAR-OMERACT combined score (κ=0.86) were better when using a ‘standardised’ scan. For the other joints, the intraobserver reliability was excellent in static images for all scores (κ=0.8–0.97) and the interobserver reliability marginally lower. When using standardised scanning in patients, the intraobserver was good (κ=0.64 for SH and the EULAR-OMERACT combined score, 0.66 for PD) and the interobserver reliability was also good especially for PD (κ range=0.41–0.92).

Conclusion

The EULAR-OMERACT score demonstrated moderate-good reliability in MCP joints using a standardised scan and is equally applicable in non-MCP joints. This scoring system should underpin improved reliability and consequently the responsiveness of US in RA clinical trials.

[Ultrasound diagnostics in Sjögren's syndrome]

Ultrasound of the salivary glands is a specific examination for detecting pathology of salivary glands in the diagnosis of Sjögren's syndrome. It is easy to learn, rapidly performed, non-invasive and inexpensive. Other imaging techniques, such as sialography and scintigraphy, are currently only rarely performed. For the examination, linear ultrasound probes with frequencies between 7 and 12 MHz are recommended. Such probes are already widely available to the rheumatologist performing musculoskeletal ultrasound. The parotid and submandibular glands are bilaterally scanned both in longitudinal and transverse planes as a standard.Normal salivary glands have uniformly hyperechoic and homogeneous tissue. They can be clearly delineated from the surrounding muscles and soft tissue and appear similar to the thyroid gland. The salivary glands are typically hypoechoic and inhomogeneous in Sjögren's syndrome. Focal or diffuse hypoechoic or anechoic foci are found in the glands. The submandibular glands may become atrophic (sagittal diameter <8 mm). Particularly in disease flares, the parotid glands may become enlarged (sagittal diameter >20 mm). The sensitivity for the diagnosis is 60 to 90% and the specificity is over 90%.Doppler sonography does not further improve the diagnostic accuracy. Sonography has thus become an important tool in the diagnosis of Sjögren's syndrome.

Definition and Reliability Assessment of Elementary Ultrasonographic Findings in Calcium Pyrophosphate Deposition Disease: A Study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force

OBJECTIVE

To define the ultrasonographic characteristics of calcium pyrophosphate crystal (CPP) deposits in joints and periarticular tissues and to evaluate the intra- and interobserver reliability of expert ultrasonographers in the assessment of CPP deposition disease (CPPD) according to the new definitions.

METHODS

After a systematic literature review, a Delphi survey was circulated among a group of expert ultrasonographers, who were members of the CPPD Ultrasound (US) Outcome Measures in Rheumatology (OMERACT) subtask force, to obtain definitions of the US characteristics of CPPD at the level of fibrocartilage (FC), hyaline cartilage (HC), tendon, and synovial fluid (SF). Subsequently, the reliability of US in assessing CPPD at knee and wrist levels according to the agreed definitions was tested in static images and in patients with CPPD. Cohen's κ was used for statistical analysis.

RESULTS

HC and FC of the knee yielded the highest interobserver κ values among all the structures examined, in both the Web-based (0.73 for HC and 0.58 for FC) and patient-based exercises (0.55 for the HC and 0.64 for the FC). Kappa values for the other structures were lower, ranging from 0.28 in tendons to 0.50 in SF in the static exercise and from 0.09 (proximal patellar tendon) to 0.27 (triangular FC of the wrist) in the patient-based exercise.

CONCLUSION

The new OMERACT definitions for the US identification of CPPD proved to be reliable at the level of the HC and FC of the knee. Further studies are needed to better define the US characteristics of CPPD and optimize the scanning technique in other anatomical sites.

The OMERACT Ultrasound Group: A Report from the OMERACT 2016 Meeting and Perspectives

Objective.

To provide an update from the Outcome Measures in Rheumatology (OMERACT) Ultrasound Working Group on the progress for defining ultrasound (US) minimal disease activity threshold at joint level in rheumatoid arthritis (RA) and for standardization of US application in juvenile idiopathic arthritis (JIA).

Methods.

For minimal disease activity, healthy controls (HC) and patients with early arthritis (EA) who were naive to disease-modifying antirheumatic drugs were recruited from 2 centers. US was performed of the hands and feet, and scored semiquantitatively (0–3) for synovial hypertrophy (SH) and power Doppler (PD). Synovial effusion (SE) was scored a binary variable. For JIA, a Delphi approach and subsequent validation in static images and patient-based exercises were used to developed preliminary definitions for synovitis and a scoring system.

Results.

For minimal disease activity, 7% HC had at least 1 joint abnormality versus 30% in the EA group. In HC, the findings of SH and PD were predominantly grade 1 whereas all grades were seen in the EA cohort, but SE was rare. In JIA, synovitis can be diagnosed based on B-mode findings alone because of the presence of physiological vascularization. A semiquantitative scoring system (0–3) for synovitis for both B-mode and Doppler were developed in which the cutoff between Doppler grade 2 and grade 3 was 30%.

Conclusion.

The first step has been taken to define the threshold for minimal disease activity in RA by US and to define and develop a scoring system for synovitis in JIA. Further steps are planned for the continuous validation of US in these areas.

Arthritis of the Knee Joint in Rheumatoid Arthritis - Evaluation of Treatment Response by Ultrasound in Daily Clinical Practice

Background:

Rheumatoid arthritis (RA) commonly involves the knee joint in up to 30% of patients. Musculoskeletal ultrasound enables the skilled clinician to easily assess disease activity.

Objective:

To evaluate the sensitivity to change of the sonography score of large joints in Rheumatology (SOLAR) for different treatments of knee arthritis in RA.

Method:

Joints were assessed by ultrasound at 4 visits. Laboratory, immunological and clinical parameters were recorded.

Results:

225 RA patients were analyzed. The DAS 28 in the subgroup receiving systemic steroids was significantly higher (p < 0.001) than in patients treated with intraarticular glucocorticosteroids (GCs) at T0, comparing the values from T0 to T3 the same appeared (p=0.003). Concerning the acute GC treatment regimens, the gray scale ultrasound (GSUS) sum score was found to be significantly higher in patients receiving intraarticular GCs versus no GCs (p=0,035), as well as in patients receiving systemic versus intraarticular GCs (p=0.001). Regarding the differences from T0 and T3, similar to the baseline analysis, a high GSUS sum score was significantly associated with intraarticular GCs, a low to no GC administration (p=0.035), while a high GSUS sum score was significantly linked to intraarticular GCs, rather than systemic GCs (p=0.008).

Conclusion:

SOLAR score is sensitive to change in knee arthritis. Intraarticular GC administration is performed in patients with high GSUS scores. Systemic administration of GC is linked to high disease activity (DAS28) rather than GSUS or power Doppler ultrasound (PDUS) results.

[Rare manifestations of axial skeleton gouty arthropathy]

Clinical manifestations of gouty arthropathy are usually acute inflammatory arthritis, bursitis and accumulation of urate crystals in the form of tophi. Manifestations on the axial skeleton are also known and have been described but occur infrequently and for this reason play a subordinate role in the awareness of rheumatologists. With dual energy computed tomography (CT) gout tophi can be detected even in unusual regions or regions that are difficult to access for puncturing. We describe two rare cases of gouty arthropathy of the axial skeleton in a 76-year-old male patient with spinal involvement and in a 53-year-old female patient with involvement of the sacroiliac joint. In both cases the diagnosis was achieved with dual energy CT.

Summary Findings of a Systematic Literature Review of the Ultrasound Assessment of Bone Erosions in Rheumatoid Arthritis

OBJECTIVE

Bone erosions in rheumatoid arthritis (RA) have been studied in an increasing amount of research. Both earlier and present classification criteria of RA contain erosions as a significant classification component. Ultrasound (US) can detect bone changes in accessible surfaces. Therefore, the study group performed a systematic literature review of assessment of RA bone erosions with US.

METHODS

A systematic search of PubMed and Embase was performed. Data on the definitions of RA bone erosions, their size, scoring, relation to synovitis, comparators, and elements of the OMERACT (Outcome Measures in Rheumatology Clinical Trials) filter were collected and analyzed.

RESULTS

The selection process identified 58 original research papers. The assessed joints were most frequently metacarpophalangeal (MCP; 41 papers), proximal interphalangeal (19 papers), and metatarsophalangeal joints (MTP; 18 papers). The OMERACT definition of RA bone erosion on US was used most often (17 papers). Second and fifth MCP and fifth MTP were recommended as target joints. Conventional radiography was the most frequently used comparator (27 papers), then magnetic resonance imaging (17 papers) and computed tomography (5 papers). Reliability of assessment was presented in 20 papers and sensitivity to change in 11 papers.

CONCLUSION

This paper presents results of a systematic literature review of bone erosion assessment in RA with US. The survey suggests that US can be a helpful adjunct to the existing methods of imaging bone erosions in RA. It analyzes definitions, scoring systems, used comparators, and elements of the OMERACT filter. It also presents recommendations for a future research agenda based on the results of the review.

Assessing Elementary Lesions in Gout by Ultrasound: Results of an OMERACT Patient-based Agreement and Reliability Exercise

OBJECTIVE

To test the reliability of the consensus-based ultrasound (US) definitions of elementary gout lesions in patients.

METHODS

Eight patients with microscopically proven gout were evaluated by 16 sonographers for signs of double contour (DC), aggregates, erosions, and tophi in the first metatarsophalangeal joint and the knee bilaterally. The patients were examined twice using B-mode US to test agreement and inter- and intraobserver reliability of the elementary components.

RESULTS

The prevalence of the lesions were DC 52.8%, tophus 61.1%, aggregates 29.8%, and erosions 32.4%. The intraobserver reliability was good for all lesions except DC, where it was moderate. The best reliability per lesion was seen for tophus (κ 0.73, 95% CI 0.61-0.85) and lowest for DC (κ 0.53, 95% CI 0.38-0.67). The interobserver reliability was good for tophus and erosions, but fair to moderate for aggregates and DC, respectively. The best reliability was seen for erosions (κ 0.74, 95% CI 0.65-0.81) and lowest for aggregates (κ 0.21, 95% CI 0.04-0.37).

CONCLUSION

This is the first step to test consensus-based US definitions on elementary lesions in patients with gout. High intraobserver reliability was found when applying the definition in patients on all elementary lesions while interobserver reliability was moderate to low. Further studies are needed to improve the interobserver reliability, particularly for DC and aggregates.

Ultrasound as an Outcome Measure in Gout. A Validation Process by the OMERACT Ultrasound Working Group

OBJECTIVE

To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group on the validation of US as a potential outcome measure in gout.

METHODS

Based on the lack of definitions, highlighted in a recent literature review on US as an outcome tool in gout, a series of iterative exercises were carried out to obtain consensus-based definitions on US elementary components in gout using a Delphi exercise and subsequently testing these definitions in static images and in patients with proven gout. Cohen's κ was used to test agreement, and values of 0-0.20 were considered poor, 0.20-0.40 fair, 0.40-0.60 moderate, 0.60-0.80 good, and 0.80-1 excellent.

RESULTS

With an agreement of > 80%, consensus-based definitions were obtained for the 4 elementary lesions highlighted in the literature review: tophi, aggregates, erosions, and double contour (DC). In static images interobserver reliability ranged from moderate to almost perfect, and similar results were found for the intrareader reliability. In patients the intraobserver agreement was good for all lesions except DC (moderate). The interobserver agreement was poor for aggregates and DC but moderate for the other components.

CONCLUSION

These first steps in evaluating the validity of US as an outcome measure for gout show that the reliability of the definitions ranged from moderate to excellent in static images and somewhat lower in patients, indicating that a standardized scanning technique may be needed, before testing the responsiveness of those definitions in a composite US score.

International Consensus for ultrasound lesions in gout: results of Delphi process and web-reliability exercise

OBJECTIVE

To produce consensus-based definitions of the US elementary lesions in gout and to test their reliability in a web-based exercise.

METHODS

The process consisted of two steps. In the first step a written Delphi questionnaire was developed from a systematic literature review and expert international consensus. This collated information resulted in four statements defining US elementary lesions: double contour (DC), tophus, aggregates and erosion. The Delphi questionnaire was sent to 35 rheumatology experts in US, asking them to rate their level of agreement or disagreement with each statement. The second step tested the reliability by a web-exercise. US images of both normal and gouty elementary lesions were collected by the participants. A facilitator then constructed an electronic database of 110 images. The database was sent to the participants, who evaluated the presence/absence of US elementary lesions. A group of 20 images was displayed twice to evaluate intra-reader reliability.

RESULTS

A total of 32 participants responded to the questionnaires. Good agreement (>80%) was obtained for US definitions on DC, tophus, aggregates and erosion in the Delphi exercise after three rounds. The reliability on images showed inter-reader κ values for DC, tophus, aggregates, erosion findings of 0.98, 0.71, 0.54 and 0.85, respectively. The mean intra-reader κ values were also acceptable: 0.93, 0.78, 0.65 and 0.78, respectively.

CONCLUSION

This, the first consensus-based US definition of elementary lesions in gout, demonstrated good reliability overall. It constitutes an essential step in developing a core outcome measurement that permits a higher degree of homogeneity and comparability between multicentre studies.

Proceedings from the 7th 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 clinical practice and research. Because the field of musculoskeletal (MSK) imaging is rapidly evolving, continuous education in the field is imperative. 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 7th annual ISEMIR meeting which took place on April 12-14, 2014 in Santa Monica, California. Presentations from the meeting can be viewed at www.isemir.org.

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.

Comparison of discrimination and prognostic value of two US Doppler scoring systems in rheumatoid arthritis patients: a prospective cohort study

OBJECTIVES

The aim of this paper is to investigate sensitivity to change (SRM), predictive validity and discriminative ability of a quantitative (QS) and a semi-quantitative (SQS) Doppler ultrasound scoring systems in patients with rheumatoid arthritis (RA) treated with anti-TNF-α therapy.

METHODS

RA patients with wrist joint affection treated with TNF-α inhibitor were followed for one year. The wrist was examined with Doppler before initiating therapy and after one year. DAS28 was determined at both visits. One person trained in the SQS system and one in the QS system evaluated the anonymised images. The SRM, predictive validity and discriminative ability for both systems were calculated using DAS28 as the measure of disease improvement.

RESULTS

Fourty-six patients with RA (80% females) were included. The mean Doppler activity at baseline was QS:24.4% (SD=17.7%) and SQS:2.0 (SD=0.6). A decrease in Doppler activity was seen for both systems after anti-TNF-α therapy. Sensitivity to change was seen, SRM=-0.52 (95%CI; -0.83 to -0.21; QS) and -0.24 (-0.53 to -0.05; SQS). Predictive value was poor (QS rs=-0.24; SQS rs=-0.05). Construct validity was; QS: rs=0.29, SQS: rs=0.23.

CONCLUSIONS

Both systems were to some extent sensitive to change. Predictive validity and discriminate capacity of both systems showed only a weak association to DAS 28 in the study population. The QS was a little superior to the SQS. The results do not necessarily reflect Doppler evaluation as being ineffective, but may be caused by DAS28 not being a perfect marker of inflammation.

Role of ultrasound in the understanding and management of vasculitis

Vasculitis is characterized by a circumferential vessel-wall thickening ('halo'), which can be visualized by modern imaging techniques. In particular, the resolution of ultrasound has increased to 0.1 mm. Ultrasound detects abnormalities that are pathognomonic even in arteries with a diameter below 1 mm. It is particularly helpful in the diagnosis of large-vessel vasculitides, such as classic temporal arteritis, large-vessel giant-cell arteritis (GCA), Takayasu arteritis and idiopathic aortitis. Echocardiography is important for determining cardiac involvement in Takayasu arteritis and also for examining the coronary arteries of children with suspected Kawasaki disease, which is a medium-vessel vasculitis. In small vessel vasculitides ultrasound has only a role for determining the distribution or organ involvement. Fast-track clinics for the diagnosis of GCA help to initiate treatment before complications such as blindness occur; patients receive appointments within 24 h in these clinics. Clinical examination and ultrasound of temporal and axillary arteries are performed by an experienced rheumatologist. In most cases this is able to determine if GCA is present. Temporal artery biopsy can be still carried out in ambivalent cases. The wall swelling of temporal arteries disappears after 2-3 weeks of glucocorticoid treatment. After 3 days of treatment, diagnosis becomes more difficult with ultrasound in some cases. In larger arteries, such as the axillary arteries, wall thickening disappears within months. It tends to be darker (more hypoechoic) in acute disease because of oedema.

Defining enthesitis in spondyloarthritis by ultrasound: results of a Delphi process and of a reliability reading exercise

OBJECTIVE

To standardize ultrasound (US) in enthesitis.

METHODS

An initial Delphi exercise was undertaken to define US-detected enthesitis and its core components. These definitions were subsequently tested on static images taken from spondyloarthritis patients in order to evaluate their reliability.

RESULTS

Excellent agreement (>80%) was obtained for including hypoechogenicity, increased thickness of the tendon insertion, calcifications, enthesophytes, erosions, and Doppler activity as core elementary lesions of US-detected enthesitis. US definitions were subsequently obtained for each elementary component. On static images, the intraobserver reliability showed a high degree of variability for the detection of elementary lesions, with kappa coefficients ranging from 0.13-1. The interobserver kappa values were variable, with the lowest kappa coefficient for enthesophytes (0.24) and the highest coefficient for Doppler activity at the enthesis (0.63).

CONCLUSION

This is the first consensus-based US definition of enthesitis and its elementary components and the first step performed to ensure a higher degree of homogeneity and comparability of results between studies and in daily clinical work.

Systemic staging for urate crystal deposits with dual-energy CT and ultrasound in patients with suspected gout

Objective of the study is to compare the diagnostic accuracy for detecting monosodium urate crystal deposits between dual-energy CT (DECT) and ultrasound (US). Sixty consecutive patients (49 men, mean age 62 years) with clinically suspected gout were included in this case-control study. DECT and US of feet, knees, hands and elbows were performed in all patients. Polarisation microscopy of synovial fluid or a score incorporating serum uric acid level, first MTP joint involvement, gender, previous patient-reported arthritis attack, cardiovascular diseases, joint redness and onset within 1 day was used as standard of reference. Standard of reference classified 39 patients as gout positive. Sixteen patients had gout and a concomitant rheumatic disease. Sensitivities for diagnosis of gout disease were 84.6 % (33/39) for DECT and 100 % (39/39) for US. Specificities were 85.7 % (18/21) for DECT and 76.2 % (16/21) for US. Positive and negative predictive values were 91.7 % (33/36) and 75.0 % (18/24) for DECT, 88.6 % (39/44) and 100 % (16/16) for US, respectively. Urate crystals were detected most frequently in MTP1 joints (DECT 20/78, US 58/78), any other toe joints (DECT 25/78, US 62/78) and knees (DECT 41/78, US 31/78). The volumetry of DECT computed a mean urate crystal deposit load of 2.1 cm(3) (SD 9.6 cm(3)). A mean effective dose of ≤0.5 mSv was estimated. DECT is more specific for the diagnosis of gout than US. However, it fails to detect small urate crystal deposits. It might be particularly useful for patients with ambivalent findings, concomitant rheumatic diseases and with non-conclusive joint aspiration.

Ultrasound in vasculitis

Colour Doppler ultrasound displays a pathognomonic circumferential wall thickening in large-vessel vasculitis. Even rather small arteries like the temporal arteries can be easily examined with modern ultrasound equipment. In addition, ultrasound can detect stenoses and acute arterial occlusions. In large-vessel giant cell arteritis, the axillary arteries are most commonly involved. Takayasu arteritis affects particularly the left subclavian and the left common carotid arteries. As ultrasound diagnosis at the temporal arteries becomes more difficult already after a few days of glucocorticoid treatment in some patients, institutions are implementing fast-track clinics for which patients receive an appointment within 24 hours. An experienced rheumatologist is able to establish a definite diagnosis in most cases with standardised history, clinical examination and ultrasound of temporal and axillary arteries. Furthermore, early diagnosis and treatment may prevent blindness.

Evaluation of the novel ultrasound score for large joints in psoriatic arthritis and ankylosing spondylitis: six month experience in daily clinical practice

Background

To evaluate the utility of the recently introduced SOLAR score (sonography of large joints in Rheumatology), which has been validated in RA patients, in a cohort of patients with Psoriatic Arthritis (PsA) and Ankylosing Spondylitis (AS) presenting with involvement of large peripheral joints.

Methods

The recently established SOLAR score has been designed to determine the degree of inflammation in the shoulder, the elbow, the hip and the knee joint in patients suffering from RA. Since large joints are frequently involved in PsA and AS, synovitis and synovial vascularity were scored semiquantitatively (grade 0–3) by grey scale (GSUS) and power Doppler ultrasound (PDUS) utilizing the validated scoring system. Each joint was scanned from different angles, the knee joint for example was divided into four areas to score for synovitis: the suprapatellar longitudinal, the medial longitudinal, the lateral longitudinal, and the posterior region. Each area was scored from 0–3, so a maximum score of 12 could be achieved. PsA and AS patients presenting with peripheral joint disease involving large joints were examined at baseline, 3 and 6 months after initiation of local or systemic therapy (DMARDs/Biologics). For evaluation of the inflammatory status, the erythrocyte sedimentation rate (ESR) was determined.

Results

A cohort of 126 patients were enclosed, and 83 of these were followed for 6 months. At baseline before modification of the therapy, patients received DMARDs (n = 83), DMARDs plus biologics (n = 30), or biologic monotherapy (n = 29). Following intervention, all US scores demonstrated a marked improvement. The GSUS and the PDUS scores for all joint areas, except the PDUS score of the hip, exhibited a significant improvement (p < 0.05), while the GSUS of the knee showed even a highly significant (p < 0.001) change. The ESR displayed a significant decrease from 27 to 19 mm (p < 0.002) representing good treatment response.

Conclusion

The SOLAR score, which has been recently introduced for RA patients, is a very suitable instrument for the qualitative and quantitative evaluation of large joint involvement in PsA and AS patients and allows for treatment monitoring.

Responsiveness in Rheumatoid Arthritis. A Report from the OMERACT 11 Ultrasound Workshop

Objective.

To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Task Force on the validity of different US measures in rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) presented during the OMERACT 11 Workshop.

Methods.

The Task Force is an international group aiming to iteratively improve the role of US in arthritis clinical trials. Recently a major focus of the group has been the assessment of responsiveness of a person-level US synovitis score in RA: the US Global Synovitis Score (US-GLOSS) combines synovial hypertrophy and power Doppler signal in a composite score detected at joint level. Work has also commenced examining assessment of tenosynovitis in RA and the role of US in JIA.

Results.

The US-GLOSS was tested in a large RA cohort treated with biologic therapy. It showed early signs of improvement in synovitis starting at Day 7 and increasing to Month 6, and demonstrated sensitivity to change of the proposed grading. Subsequent voting questions concerning the application of the US-GLOSS were endorsed by > 80% of OMERACT delegates. A standardized US scoring system for detecting and grading severity of RA tenosynovitis and tendon damage has been developed, and acceptable reliability data were presented from a series of exercises. A preliminary consensus definition of US synovitis in pediatric arthritis has been developed and requires further testing.

Conclusion.

At OMERACT 11, consensus was achieved on the application of the US-GLOSS for evaluating synovitis in RA; and work continues on development of RA tenosynovitis scales as well as in JIA synovitis.

Musculoskeletal ultrasound training and competency assessment program for rheumatology fellows

OBJECTIVES

The purpose of this study was to establish standards for musculoskeletal ultrasound competency through knowledge and skills testing using criterion-referenced methods.

METHODS

Two groups of rheumatology fellows trained in musculoskeletal ultrasound through a standardized curriculum, which required submission of ultrasound studies for review over 8 months. Both groups then completed written and practical examinations in musculoskeletal ultrasound. Instructors, advanced users, and intermediate users of musculoskeletal ultrasound served as comparison groups. A passing score (competency) was established for the written examination by the Angoff procedure and for the practical examination by the borderline method.

RESULTS

Thirty-eight fellows (19 in each group) took the final examination. Five fellows failed the written examination, and 1 failed the practical examination, whereas none of the advanced users failed. Written examination scores did not differ between the two fellow groups (74% versus 70%; P > .05), were reliable, and were able to discriminate between the intermediate and advanced groups. Practical and written examination results correlated in both groups (first group, r = 0.70; P = .0008; second group, r = 0.59; P = .009).

CONCLUSIONS

Criterion-referenced methods were used for the first time to determine fellow musculoskeletal ultrasound competency. The examination used to determine competency was reproducible, was reliable, and could differentiate musculoskeletal ultrasound users with different levels of experience. Most rheumatology fellows completing our program passed the written and practical examinations, suggesting achievement of basic musculoskeletal ultrasound competency.

EFSUMB minimum training requirements for rheumatologists performing musculoskeletal ultrasound

In order to optimize and standardize musculoskeletal ultrasonography education for rheumatologists, there is a need for competency assessments addressing the required training and practical and theoretical skills. This paper describes how these competency assessments for rheumatologists were developed and what they contain.

[Polymyalgia rheumatica]

Polymyalgia rheumatica is characterized by bilateral pain in the shoulder and pelvic girdles, malaise, morning stiffness and weight loss. The erythrocyte sedimentation rate (ESR) and the C-reactive protein (CRP) level are elevated. Imaging using ultrasound, magnetic resonance imaging (MRI) or positron emission tomography (PET) displays inflammatory changes in the painful anatomical areas. Nearly all patients are older than 50 years and the average age is 70-75 years. Polymyalgia rheumatica occurs 2-3 times more often in women than in men and some patients exhibit temporal arteritis or giant cell arteritis. Symptoms rapidly decrease with glucocorticoid treatment and the dose can normally be reduced during the course of the disease. Methotrexate may be given only if high glucocorticoid doses do not sufficiently control symptoms. On average treatment can be stopped after 2 years.

Monotherapy with tocilizumab or TNF-alpha inhibitors in patients with rheumatoid arthritis: efficacy, treatment satisfaction, and persistence in routine clinical practice

This study aims to investigate the use of biological disease-modifying antirheumatic drugs (bDMARDs) as monotherapy in patients with rheumatoid arthritis (RA) in "real world" clinical settings and to compare tumor necrosis factor (TNF) inhibitors and tocilizumab monotherapy in terms of efficacy and patient and clinician satisfaction with treatment. This study made use of a retrospective, cohort-19 based study including included data from 254 patients (TNF inhibitors n = 128; tocilizumab n = 126) managed in 30 centers throughout Germany. Efficacy of monotherapy and patient and physician overall satisfaction with treatment were assessed at baseline, 3, and 6 months of monotherapy using a range of measures including Disease Activity Score 28 joint (DAS28), swollen joint count (SJC) and tender joint count (TJC), and visual analogue scales (VAS). Between 18 and 41 % of patients treated with bDMARDs received the agent as monotherapy. Intolerance to DMARDs, contraindications for combination therapy, and comorbidities were the most common reasons for introduction of bDMARD monotherapy. Mean DAS28 (erythrocyte sedimentation rate, ESR) was significantly lower at 3 and 6 months following tocilizumab vs. TNF inhibitors (p ≤ 0.001). Joint counts improved from baseline to month 6 in both groups (SJC -5.1 vs. -3.7 and TJC -5.6 vs. -5.1, for tocilizumab and TNF inhibitors, respectively). Patient as well as physician satisfaction (VAS 100 mm scale) was significantly higher for tocilizumab vs. TNF inhibitors (75.3 vs. 66.8; p = 0.001 and 74.9 vs. 67.1, p = 0.003, respectively). Significantly more patients remained on tocilizumab monotherapy vs. TNF-inhibitor monotherapy (89.7 vs. 75.8 %; p < 0.01). Monotherapy with bDMARDs is common in routine clinical practice. Tocilizumab monotherapy appeared to be superior over TNF-inhibitor monotherapy with respect to DAS28 and drug adherence.

The diagnosis and treatment of giant cell arteritis

BACKGROUND

Giant cell arteritis (GCA) is the most common systemic vasculitis in persons aged 50 and above (incidence, 3.5 per 100,000 per year). It affects cranial arteries, the aorta, and arteries elsewhere in the body, e.g., in the limbs.

METHODS

We selectively review the pertinent literature, including guidelines and recommendations from Germany and abroad.

RESULTS

The typical symptoms of new-onset GCA are bitemporal headaches, jaw claudiacation, scalp tenderness, visual disturbances, systemic symptoms such as fever and weight loss, and polymyalgia. The diagnostic assessment comprises laboratory testing (erythrocyte sedimentation rate, C-reactive protein), imaging studies (duplex sonography, high-resolution magnetic resonance imaging, positron-emission tomography), and temporal artery biopsy. The standard treatment is with corticosteroids (adverse effects: diabetes mellitus, osteoporosis, cataract, arterial hypertension). A meta-analysis of three randomized controlled trials led to a recommendation for treatment with methotrexate to lower the recurrence rate and spare steroids. Patients for whom methotrexate is contraindicated or who cannot tolerate the drug can be treated with azathioprine instead.

CONCLUSION

Giant cell arteritis, if untreated, progresses to involve the aorta and its collateral branches, leading to various complications. Late diagnosis and treatment can have serious consequences, including irreversible loss of visual function.

Imaging in vasculitis

Vasculitides may involve small, medium-sized or large arteries. In small-vessel vasculitides imaging studies of lungs, nasal sinuses, cerebrum, heart and other organs are important for determining disease extension and disease activity. Aneurysms are a hallmark of medium-sized artery vasculitides. In large-vessel vasculitis, imaging studies depict homogeneous, circumferential wall swelling and smoothly tapered luminal narrowing. Ultrasound and high-resolution magnetic resonance imaging (MRI) show characteristic wall abnormalities in temporal and occipital arteries whereas ultrasound, MRI, MR angiography, computed tomography (CT), CT angiography and positron emission tomography delineate characteristic features in extra-cranial arteries that are affected in large-vessel giant cell arteritis, Takayasu arteritis and idiopathic aortitis. Conventional angiography has still its place for therapeutic interventions. Imaging has led to a better understanding of the nature and distribution of vasculitides. It significantly facilitates diagnosis of patients with suspected vasculitis.

Low-field MRI versus ultrasound: which is more sensitive in detecting inflammation and bone damage in MCP and MTP joints in mild or moderate rheumatoid arthritis?

OBJECTIVES

The aim of the present paper is to determine if the ultrasound of hands and feet is comparable to the MRI of the dominant hand to detect erosive disease and inflammation in mild or moderate rheumatoid arthritis (RA).

METHODS

Twenty-six patients (14 females; mean age, 48 years) with active mild or moderate RA (mean DAS28, 3.9; mean disease duration, 19 months) were examined clinically, by ultrasound and by gadolinium-enhanced low-field MRI at baseline, after 6 and 12 months (78 examinations). Radiographs from hands and forefeet were taken at baseline and after 12 months. MRI was performed at the clinically most active (dominant) hand or forefoot evaluating the MCP 1-5 or MTP 1-5 joints. Ultrasound examination additionally included all other 2nd, 5th MCP and 5th MTP joints.

RESULTS

MRI and ultrasound detected erosive disease in 67 and 56 of 78 examinations, respectively (p<0.01); radiography only in 8 of 52 examinations (p<0.001). MRI and ultrasound were equally sensitive to detect synovitis (in 64 and 66 examinations). Synovial power Doppler signals were present in 38 ultrasound examinations. Bone marrow oedema was present in 37 MRI examinations. Ultrasound was more sensitive than MRI to detect tenosynovitis (in 30 vs. 15 examinations; p=0.001).

CONCLUSIONS

MRI of the dominant hand and bilateral ultrasound of MCP and MTP joints are superior to x-ray to detect erosive disease in mild and moderate RA. MRI is slightly, but significantly more sensitive than ultrasound for erosive disease, while ultrasound is more sensitive to detect tenosynovitis. Ultrasound and MRI are comparably sensitive to detect synovitis.

Which knee and probe position determines the final diagnosis of knee inflammation by ultrasound? Results from a European multicenter study

PURPOSE

To investigate which knee and probe position best identifies knee inflammation and to determine a cut-off level for abnormal synovial effusion.

MATERIALS AND METHODS

18 experienced sonographers (all rheumatologists) performed ultrasound examinations of the knee joint in patients with knee symptoms and in healthy controls. Each sonographer performed longitudinal suprapatellar ultrasound scans using 9 different configurations at each knee: Midline, parapatallar lateral and parapatellar medial from midline in neutral position (0°) with and without quadriceps muscle contraction and in 30° flexion of the knee. The presence of synovial effusion (SE), the effusion measured in millimeters and the presence of synovial hypertrophy (SH) was noted.

RESULTS

A total of 298 knees of 149 subjects (129 patients and 20 controls) were examined. The detection of SH is more sensitive and specific than the detection of SE, independently of the knee and probe position, for the final diagnosis of abnormality. The detection of both synovial hypertrophy and effusion in the knee in neutral position (0°) with quadriceps contraction and with the probe in the midline position, are the best independent predictors for knee abnormalities. Knee effusion > 3.2 mm measured with the probe in the lateral aspect of the knee is the best diagnostic characteristics for predicting pathological SE.

CONCLUSION

The best combination for detecting SH and SE is obtained by placing the probe in the midline position with the knee in 0° with quadriceps contraction. A cut-off value for pathological effusion may be obtained in the lateral aspect of the knee.

[Giant-cell arteritis: update: diagnosis and therapy]

Giant-cell arteritis (GCA) is the most common form of vasculitis in patients over 50 years old. Loss of vision is the most common severe complication but involvement of extracranial arteries including the aorta is more frequent than previously assumed. The role of dendritic and T-cells indicates the presence of an antibody but a clear association with underlying infections has not yet been demonstrated. Even if the inflammation parameters in blood are mostly increased in the diagnosis of GCA, specific laboratory tests for the diagnosis of GCA are not available. Of the imaging procedures ultrasonography, magnetic resonance imaging and (18)F-fluorodeoxyglucose positron emission tomography can be useful to localize and estimate the extent of vascular involvement. Glucocorticoids are still the standard therapy of GCA, whereby the cumulative dose can possibly be reduced by additional methotrexate. In addition acetylsalicylic acid is recommended as prophylaxis against cardiovascular and cerebrovascular events as well as prophylaxis and therapy of accompanying osteoporosis.

Reliability of the novel 7-joint ultrasound score: results from an inter- and intraobserver study performed by rheumatologists

OBJECTIVE

To assess the inter- and intraobserver reliability of 26 rheumatologists when performing the 7-joint ultrasound score (US7).

METHODS

Six patients with rheumatoid arthritis were examined by 26 sonographers in 12 rater groups who performed the US7 score. The US7 score includes the clinically dominant wrist, the second and third metacarpophalangeal (MCP) and proximal interphalangeal joints, and the second and fifth metatarsophalangeal (MTP) joints, which were evaluated for synovitis, tenosynovitis/paratenonitis, and erosions from the dorsal side and palmar/plantar aspects by gray-scale and power Doppler (PD) ultrasound. Additional lateral scans were performed at the MCP2 and MTP5 joints. All of the groups repeated the examination in 4 patients in order to calculate the intraobserver reliability. The results of one group that included 2 expert sonographers were considered as the reference standard. Kappa values, median agreement rates (interobserver), and P values (intraobserver evaluation) were calculated.

RESULTS

The median overall kappa value for detecting synovitis was 0.51, for tenosynovitis/paratenonitis was 0.57, and for erosions was 0.45. In detail, the best interobserver results were found for the detection of erosions in the MTP2 joint from the plantar aspect (κ = 1; median agreement rate 89.4%) and for PD signal detection in the palmar wrist region (κ = 0.79; median agreement rate 78.8%). Good agreement was found for detecting erosions in the MCP2 joint from the radial side (κ = 0.67; median agreement rate 77.3%).

CONCLUSION

The inter- and intraobserver reliability of the US7 score shows moderate to substantial kappa values and good agreements. Therefore, this ultrasound score has the potential to be an important imaging tool, including multicenter analysis to assess structural changes.