Best practice in rheumatology new developments in ultrasound and MRI imaging of pediatric rheumatic diseases

The evidence base for ultrasound and MRI imaging in pediatric rheumatic diseases continues to grow, enabling the routine clinical use of the two techniques that complement each other. Ultrasound imaging has a superior spatial resolution, the ability to assess several joints at the same time without sedation and provides very detailed assessments of important structures like the entheses. MRI has advantages in the assessment of osteochondral damage and certain anatomic regions like the temporomandibular joint (TMJ) and the axial skeleton. Significant progress in the standardization of image acquisition and quantification of findings allows the utilisation of both techniques as an outcome measure. This will improve the standard of care in pediatric rheumatic diseases where objective measurements of disease activity are urgently needed. Finally, the integration of artificial intelligence (AI) represents a groundbreaking development in the field and potential applications will be discussed.

Juvenile Idiopathic Arthritis and Spondylarthritis

Juvenile idiopathic arthritis (JIA) is a heterogeneous disorder affecting children < 16 years of age. The clinical heterogeneity translates to imaging, where no specific joint is affected. This article highlights a general imaging approach to JIA, using specific examples of the knee, hand, and wrist as the typical joints affected. We then focus on unique joints that are commonly affected by JIA: the temporomandibular joint, the joints of the upper cervical spine, and the sacroiliac joint. For these latter anatomical sites, regional anatomy and development, location-specific imaging considerations, and arthritis, treatment decision making, and potential differential considerations are reviewed. We highlight, where applicable, a multimodal approach to imaging using developed or developing standardized scoring systems.

Imaging in Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) poses clinical challenges because of its heterogeneous categories of chronic arthritis. Although conventional radiography aids with assessment of joint damage, MRI and ultrasound offer more sensitive evaluation of joint changes related to inflammation and damage in JIA. MRI and ultrasound have the potential to complement clinical assessment, monitor inflammation and damage, guide treatment decisions, and improve outcomes in JIA. Future research aims to enhance standardization and reliability and bolster the predictive value of imaging in clinical practice.

The importance of ultrasound examination in care of juvenile idiopathic arthritis patients: 9 months follow-up study

Introduction

Juvenile idiopathic arthritis (JIA) is a group of rare musculoskeletal disorders with chronic inflammation of joints, typically manifesting before the age of 16 years. The assessment of disease activity remains pivotal in JIA treatment decisions, particularly during clinical remission. While musculoskeletal ultrasound (MSUS) has shown promise in detecting subclinical synovitis, longitudinal data on MSUS features in JIA remains limited. The aim of this study was to evaluate the prevalence of subclinical synovitis observed in MSUS over a follow-up period in JIA patients. Additionally, it sought to assess the consistency and correlation between clinical findings, standardized composite clinical score (JADAS10), and MSUS-detected synovitis during 9 months follow-up.

Patients and methods

a prospective single-center study was conducted, enrolling all consecutive JIA patients (excluding systemic JIA) seen at the study center in one year period. At three-months intervals over a 9 months period (M0, M3, M6 and M9), patients underwent clinical examination, laboratory tests, and MSUS assessment. Data on demographic characteristics, disease profile, and treatment were collected. Patients were categorized into active disease (ACT) or remission (REM) groups based on Wallace criteria and JADAS10 scores using previously validated thresholds. The ultrasound assessments adhered to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) pediatric group, covering 40 joints, were performed by two ultrasonographers at every visit. Subclinical synovitis was defined as synovitis detected exclusively by MSUS. Spearman's correlation coefficients (rs) were used to evaluate the association between MSUS, clinical data, and outcome measures, such as active joint count (ACJ), patient's/parent's global assessment of disease activity (PaGA), physician's global assessment of disease activity (PhGA) and JADAS10.

Results

subclinical synovitis was evident in 5.2% of all joints and in 80.6% of the patients at baseline. During the follow-up period, signs of subclinical synovitis decreased to 3.8% of joints, however, the proportion of affected patients remained high (67.7%), with the majority in REM group. Despite the consistent strong correlation between PaGA and PhGA throughout the study (rs > 0.895; p < 0.001), both measures displayed moderate (rs = 0.647; p < 0.001) to weak (rs = 0.377; p = 0.04) correlations with MSUS findings. Notably, PaGA remained significantly correlated with MSUS at the M9 visit (rs = 0.377, p = 0.04), while PhGA showed no correlation (p = 0.094).

Conclusions

The study results indicate the persistence of subclinical inflammation detected by MSUS in a significant proportion of JIA patients, even during clinical remission. Moreover, the findings suggest that conventional measurements of JIA activity may be insufficient for assessing patients in clinical remission.

Prevalence of ultrasound and clinical findings suggestive of inflammatory arthritis in children with skin psoriasis

OBJECTIVE

To evaluate the prevalence of clinical and US (grey-scale and Doppler) abnormalities in joints, periarticular structures and nails of children affected by skin psoriasis (PsO).

METHODS

We conducted a cross-sectional study including consecutive children affected by PsO. A systematic clinical and US evaluation of joints, entheses, tendons and nails were performed by independent examiners blinded to each other's assessment.

RESULTS

A total of 57 children [26 girls (46%)] with a mean age of 9 years (s.d. 4) were divided into two groups, asymptomatic (Asy, 42 children) and symptomatic (Sy, 15 children), according to musculoskeletal pain. Differences were observed between the two groups in relation to age [9 years (s.d. 3) vs 11 years (s.d. 4), P < 0.05], PsO duration [2.4 years (s.d. 2.4) vs 5.4 years (s.d. 3.9), P < 0.001], systemic treatment [23 (54.8%) vs 2 [13.3%], P < 0.01], tender joint count [0 vs 12 children (80%), P < 0.001], swollen joint count [0 vs 3 children (20%), P < 0.01] and entheseal pain [0 vs 10 (66.7%), P < 0.001] in Asy and Sy children, respectively. US evaluation showed statistically significant differences between the Asy and Sy groups for the presence of US abnormalities [16/42 (38%) vs 12/15 (80%)], synovitis [1/42 (2%) vs 4/15 (25%)] and enthesitis [4/42 (9.5%) vs 5/15 (33%)]. Three children in the Sy group were classified with juvenile PsA (JPsA).

CONCLUSIONS

US abnormalities were higher in the Sy group, with synovitis and enthesitis as the most prevalent findings. Asy patients were more frequently under systemic treatment. US and a systematic clinical evaluation are useful tools for detecting subclinical JPsA in children with PsO and musculoskeletal symptoms.

A clinical perspective on imaging in juvenile idiopathic arthritis

In recent years, imaging has become increasingly important to confirm diagnosis, monitor disease activity, and predict disease course and outcome in children with juvenile idiopathic arthritis (JIA). Over the past few decades, great efforts have been made to improve the quality of diagnostic imaging and to reach a consensus on which methods and scoring systems to use. However, there are still some critical issues, and the diagnosis, course, and management of JIA are closely related to clinical assessment. This review discusses the main indications for conventional radiography (XR), musculoskeletal ultrasound (US), and magnetic resonance imaging (MRI), while trying to maintain a clinical perspective. The diagnostic-therapeutic timing at which one or the other method should be used, depending on the disease/patient phenotype, will be assessed, considering the main advantages and disadvantages of each imaging modality according to the currently available literature. Some brief clinical case scenarios on the most frequently and severely involved joints in JIA are also presented.

Diagnostic Accuracy Study of the Pediatric-Specific Ultrasound Scoring System for the Knee Joint in Children With Juvenile Idiopathic Arthritis

OBJECTIVE

We undertook this study to validate the Pediatric Arthritis Ultrasound Scoring System for the knee joint (PAUSS-knee) in children with juvenile idiopathic arthritis (JIA).

METHODS

Children with JIA were enrolled to prospectively receive a musculoskeletal ultrasound (MSUS) examination of the knee and a physical examination to determine presence/absence of clinical arthritis. MSUS images were scored using the PAUSS-knee, a semiquantitative MSUS scoring system (0-3, normal to severe) for B-mode and power Doppler mode. In addition to MSUS, a subset of participants also received magnetic resonance imaging (MRI) of the knee, which was scored according to the combined Juvenile Arthritis MRI Scoring (JAMRIS) system. Spearman's correlations (rs ) were used to calculate associations between variables. Test characteristics of the PAUSS-knee were calculated with MRI as the reference standard. Inflammatory biomarkers were assessed in synovial fluid from involved knees.

RESULTS

Eighty children with JIA contributed 112 MSUSs and 25 MRIs of the knee. Of the knees, 41% (n = 46) had clinical evidence of arthritis. The B-mode PAUSS-knee score moderately correlated with clinically determined arthritis (rs = 0.54, P < 0.001) and strongly correlated with the JAMRIS score (rs = 0.75, P < 0.001). Compared with MRI, the area under the curve for the B-mode PAUSS-knee was 0.92. For a cutoff of >1, the B-mode PAUSS-knee had a sensitivity of 83% and specificity of 82%. Biomarker analysis indicates that interleukin-2R levels correlate with PAUSS score.

CONCLUSION

Our data indicate that the PAUSS-knee has excellent accuracy for the diagnosis of arthritis when compared with MRI. The PAUSS-knee has the potential to effectively inform JIA medical decision-making in real time.

Low prevalence of subclinical synovitis in patients with juvenile idiopathic arthritis (JIA) in long-term clinical remission on medication

Subclinical synovitis is highly prevalent in patients with JIA in clinical remission (CR) with a short duration. The objective was to evaluate its prevalence by ultrasound (US) in patients with JIA in long CR during a one-year follow-up. In this prospective and longitudinal study, we included 76 patients with JIA according to ILAR with CR by the Wallace modified criteria and JADAS27 and compared them with 22 patients with active disease. Clinical and demographic characteristics were recorded. US evaluation was by 10-joint count. Differences in US evaluations were analyzed by the Mann-Whitney U test. There were no differences among the two group with regard to disease duration at enrollment, and age (p = 0.540 and p = 0.080, respectively), but JADAS 27, CHAQ, and acute phase reactants were significantly higher (p < 0.001) in the clinically active group. The prevalence of subclinical synovitis at baseline and the end of the study in the CR group was 18.4% and 11.8%, respectively, while it was 100% and 40.9% in the active disease group. Subclinical synovitis at baseline was significantly more prevalent in the clinically active group (elbow, p = 0.01; wrist, p = 0.001; MCP 2, p = 0.001; knee, p = 0.001 and ankle p = 0.001; and PD only in the ankle, p = 0.002). The concordance of inter-reader reliability in all evaluated joints was excellent (p = 0.001). Although the prevalence of subclinical synovitis is low in patients with JIA with long-term clinical remission on medication, a percentage of patients continue to have subclinical involvement that could predict the risk of relapse and structural damage. Key Points • Subclinical synovitis is less prevalent in JIA in long-term clinical remission compared to patients in short-term remission. • The persistence of imaging signs of inflammation in a significant percentage of patients may indicate the need for ongoing medication.

Ankle and Foot: Focus on Inflammatory Disease

The ankle and foot have numerous bones and complex joints that can be affected by several types of inflammatory arthritis with different patterns and various radiologic signs, depending on the phase of the disease. Involvement of these joints is most frequently seen in peripheral spondyloarthritis and rheumatoid arthritis in adults and juvenile idiopathic arthritis in children. Although radiographs are a mainstay in the diagnostic process, ultrasonography and especially magnetic resonance imaging allow early diagnosis and are crucial diagnostic tools. Some diseases have typical features based on target populations (e.g., adults versus children, men versus women), but others may have overlapping imaging characteristics. We highlight key diagnostic features and describe appropriate investigations to guide clinicians toward the correct diagnosis and provide support during disease monitoring.

Comprehensive and reliable sonographic assessment and scoring system for inflammatory lesions of the paediatric ankle

OBJECTIVE

The clinical decision-making process in paediatric arthritis lacks an objective, reliable bedside imaging tool. The aim of this study was to develop a US scanning protocol and assess the reliability of B-mode and Doppler scoring systems for inflammatory lesions of the paediatric ankle.

METHODS

As part of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) US group, 19 paediatric rheumatologists through a comprehensive literature review developed a set of standardized views and scoring systems to assess inflammatory lesions of the synovial recesses as well as tendons of the paediatric ankle. Three rounds of scoring of still images were followed by one practical exercise. Agreement among raters was assessed using two-way single score intraclass correlation coefficients (ICC).

RESULTS

Of the 37 initially identified views to assess the presence of ankle synovitis and tenosynovitis, nine views were chosen for each B-mode and Doppler mode semi-quantitative evaluation. Several scoring exercises and iterative modifications resulted in a final highly reliable scoring system: anterior tibiotalar joint ICC: 0.93 (95% CI 0.92, 0.94), talonavicular joint ICC: 0.86 (95% CI 0.81, 0.90), subtalar joint ICC: 0.91 (95% CI 0.88, 0.93) and tendons ICC: 0.96 (95% CI 0.95, 0.97).

CONCLUSION

A comprehensive and reliable paediatric ankle US scanning protocol and scoring system for the assessment of synovitis and tenosynovitis were successfully developed. Further validation of this scoring system may allow its use as an outcome measure for both clinical and research applications.

Associations between power Doppler ultrasound findings and B-mode synovitis and clinical arthritis in juvenile idiopathic arthritis using a standardised scanning approach and scoring system

OBJECTIVES

To describe power Doppler (PD) ultrasound findings in joint regions with B-mode (BM) synovitis using a standardised scanning protocol and scoring system in patients with juvenile idiopathic arthritis (JIA). Further, to examine associations between PD findings and BM synovitis, clinical arthritis, patient characteristics and disease activity.

METHODS

In this cross-sectional study, one experienced ultrasonographer, blinded to clinical findings, performed ultrasound examinations in 27 JIA patients with suspected clinical arthritis. The elbow, wrist, metacarpophalangeal 2-3, proximal interphalangeal 2-3, knee, ankle and metatarsophalangeal 2-3 joints were assessed bilaterally and scored semiquantitatively (grades 0-3) for BM and PD findings using a joint-specific scoring system with reference atlas. Multilevel mixed-effects ordered regression models were used to explore associations between PD findings and BM synovitis, clinical arthritis, age, sex, JIA subgroups, disease duration and 10-joint Juvenile Arthritis Disease Activity Score (JADAS10).

RESULTS

Twenty-one girls and six boys, median age (IQR) 8 years (6-12 years) were included. Overall, 971 joint regions were evaluated by ultrasound, 129 had BM synovitis and were assessed for PD. PD findings were detected in 45 joint regions (34.9%), most frequently in the parapatellar recess of the knee (24.4%). Increasing PD grades were associated with higher BM grades (OR=5.0,p<0.001) and with clinical arthritis (OR=7.4,p<0.001) but not with age, sex, JIA subgroups, disease duration or JADAS10.

CONCLUSION

Increasing severity of PD findings were significantly associated with BM synovitis and with clinical arthritis. This suggests that PD signals detected using a standardised ultrasound examination and scoring system can reflect active disease in JIA patients.

Musculoskeletal Ultrasound in Childhood Arthritis Limited Examination: A Comprehensive, Reliable, Time-Efficient Assessment of Synovitis

OBJECTIVE

To develop and initially validate a comprehensive pediatric musculoskeletal ultrasound (MSUS) joint-specific scoring system, and to determine the minimum number of joints needed to identify active disease.

METHODS

A semiquantitative scoring system was developed by consensus and initially validated by interrater reliability using intraclass correlation coefficients (ICCs). Subsequently, newly diagnosed juvenile idiopathic arthritis patients with an active joint count of >4 had a 42-joint MSUS performed at baseline and 3 months using this protocol. A minimum set of joints needed to identify all patients with synovitis on MSUS was obtained through a data reduction process. Spearman's correlation (rs ) was calculated to determine the association between MSUS findings and clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10). Standardized response means (SMRs) were used to assess change over time.

RESULTS

The final joint-specific scoring system revealed an excellent interrater reliability (ICC 0.81-0.96) for all joints. Thirty patients were enrolled. Scanning 5 joints bilaterally (wrists, second and third metacarpophalangeal joints, knees and ankles) captured 100% of children with B-mode synovitis and had moderate correlation with the cJADAS10 at baseline (rs  = 0.45). Mean ultrasound scores at baseline and follow-up were 28.3 and 22.3, with an SRM of 0.69 (P = 0.002) for 42 joints, and 36 and 27.7, with an SRM of 0.76 (P = 0.003) for the reduced joints, respectively.

CONCLUSION

A limited MSUS examination called musculoskeletal ultrasound in childhood arthritis limited examination (MUSICAL) captures all patients with active synovitis, and our new joint-specific scoring system is highly reliable and sensitive to change.

Reliability of the Pediatric Specific Musculoskeletal Ultrasound Scoring Systems for the Elbow, Wrist, and Finger Joints

OBJECTIVE

Musculoskeletal ultrasound (MSUS) is increasingly being used in the evaluation of pediatric musculoskeletal diseases. In order to provide objective assessments of arthritis, reliable MSUS scoring systems are needed. Recently, joint-specific scoring systems for arthritis of the pediatric elbow, wrist, and finger joints were proposed by the Childhood Arthritis and Rheumatology Research Alliance (CARRA) MSUS workgroup. This study aimed to assess the reliability of these scoring systems when used by sonographers with different levels of expertise.

METHODS

Members of the CARRA MSUS workgroup attended training sessions for scoring the elbow, wrist, and finger. Subsequently, scoring exercises of B mode and power Doppler (PD) mode still images for each joint were performed. Interreader reliability was determined using 2-way single-score intraclass correlation coefficients (ICCs) for synovitis and Cohen [Formula: see text] for tenosynovitis.

RESULTS

Seventeen pediatric rheumatologists with different levels of MSUS expertise (1-15 yrs) completed a 2-hour training session and calibration exercise for each joint. Excellent reliability (ICC > 0.75) was found after the first scoring exercise for all the finger and elbow views evaluated on B mode and PD mode, and for all of the wrist views on B mode. After a second training session and a scoring exercise, the wrist PD mode views reached excellent reliability as well.

CONCLUSION

The preliminary CARRA MSUS scoring systems for assessing arthritis of the pediatric elbow, wrist, and finger joints demonstrate excellent reliability among pediatric MSUS sonographers with different levels of expertise. With further validation, this reliable joint-specific scoring system could serve as a clinical tool and scientific outcome measure.

Contribution of Ultrasound in Current Practice for Managing Juvenile Idiopathic Arthritis

The interest and application of musculoskeletal ultrasound (MSUS) in juvenile idiopathic arthritis (JIA) are increasing. Numerous studies have shown that MSUS is more sensitive than clinical examination for detecting subclinical synovitis. MSUS is a well-accepted tool, easily accessible and non-irradiating. Therefore, it is a useful technique throughout JIA management. In the diagnostic work-up, MSUS allows for better characterizing the inflammatory involvement. It helps to define the disease extension, improving the classification of patients into JIA subtypes. Moreover, it is an essential tool for guiding intra-articular and peritendinous procedures. Finally, during the follow-up, in detecting subclinical disease activity, MSUS can be helpful in therapeutic decision-making. Because of several peculiarities related to the growing skeleton, the MSUS standards defined for adults do not apply to children. During the last decade, many teams have made large efforts to define normal and pathological US features in children in different age groups, which should be considered during the US examination. This review describes the specificities of MSUS in children, its applications in clinical practice, and its integration into the new JIA treat-to-target therapeutic approach.

Criteria Associated with Treatment Decisions in Juvenile Idiopathic Arthritis with a Focus on Ultrasonography: Results from the JIRECHO Cohort

BACKGROUND

The treatment of children with juvenile idiopathic arthritis (JIA) to prevent disability is a major challenge in paediatric rheumatology. The presence of synovitis, which is difficult to detect in children, is associated with structural damage. Musculoskeletal ultrasonography (MSUS) can be used in patients with JIA to reveal subclinical synovitis.

OBJECTIVE

The primary aim was to determine whether the use of MSUS was associated with therapeutic modification in patients with JIA. The secondary aim was to identify other factors associated with therapeutic decisions.

METHODS

We conducted an observational study based on the JIRECHO multi-centre cohort, which was developed to provide a systematic MSUS follow-up for patients with JIA. Follow-up occurred every 6 months and included clinical and MSUS examinations. We included children who underwent MSUS of the elbows, wrists, second metacarpophalangeal joints, knees and ankles, which was performed by expert sonographers. Clinical and biological data, disease activity scores and information on therapeutics were collected.

RESULTS

A total of 185 visits concerning 112 patients were recorded. Three groups were defined according to the therapeutic decision: escalation (22%, n = 40), de-escalation (14%, n = 26) or stable (64%, n = 119). In the "therapeutic escalation" group: the presence of ultrasonographic synovitis in B-mode and the presence of grade 2 or 3 synovitis in B-mode were not significantly more frequent than in the "stable therapeutic or de-escalation" group (80% versus 65%, p = 0.06; 33% versus 19%, p = 0.06), and the patient's and physician's visual analogue scale (VAS) scores, the clinical JADAS and the C-reactive protein level were significantly higher, but only physician's VAS score remained in the model of logistic regression. In the "therapeutic de-escalation" group: there was no difference in the presence of US synovitis compared with the "stable therapeutic or escalation" group (62% versus 69%, p = 0.48).

CONCLUSION

Even though US synovitis tended to be more frequent in patients with therapeutic escalation, the study did not show that the presence of synovitis in MSUS was statistically associated with therapeutic modifications in patients with JIA. Treatment remained stable despite the presence of US synovitis.

Ultrasonographic Evaluation of Sub-Clinical Synovitis in Juvenile Idiopathic Arthritis: The Disease Classification and Management

Background: Ultrasonography (USG) is a perfect device for analyzing more than one joint in rather brief intervals of time and is well accepted by children with no harmful ionizing radiation, usually does not require sedation, and can be carried out without difficulty in an outpatient setting. Purpose: To demonstrate the ability of ultrasonography (USG) in detecting clinical and subclinical synovitis in children with juvenile idiopathic arthritis (JIA) and compare the USG findings with clinical findings. Methods: 20 patients with JIA diagnosed according to the ILAR criteria were include. A total of 208 joints were examined both clinically and ultrasonographically for detection of synovitis. The presence of subclinical synovitis detected by USG was sought and its effect on the classification of JIA was assessed. USG assessment was done using the High-Resolution Linear probe including both grey scale and Power Doppler assessment. Results: The mean age of patients was 10.2 years with average disease duration of 5.9 months. A total of 49 joints (23.5%) had clinical synovitis and 59 joints (28.4%) had USG synovitis out of a total of 208 joints. A total of 14 joints had subclinical synovitis (8.8% out of the 159 clinically normal joints) upon USG. USG additionally brought about classifying three patients as having poly articular disorder who had been considered as oligo articular upon clinical examination. Conclusion: USG assessment of subclinical synovitis in JIA patients is an essential component of classifying the disease and detects more joints with synovitis than clinical examination; however, both are complimentary and should be used in combination in all patients with JIA.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Enthesitis-related arthritis: monitoring and specific tools

OBJECTIVES

In this article, the authors aimed to review the different tools used in the monitoring of enthesitis-related arthritis.

SOURCES

The authors performed a literature review on PubMed, Google Scholar, and Scopus databases. The dataset included the original research and the reviews including patients with enthesitis-related arthritis or juvenile spondylarthritis up to October 2020.

SUMMARY OF FINDING

Enthesitis-related arthritis is a category of juvenile idiopathic arthritis. It is characterized by the presence of enthesitis, peripheral arthritis, as well as axial involvement. The only validated tool for disease activity measurement in juvenile idiopathic arthritis is the Disease Activity Score: It has proven its reliability and sensitivity. Nevertheless, due to an absence of validated evaluation tools, the extent of functional impairment, as well as the children and parents' perception of the disease, could not be objectively perceived. Despite the great progress in the field of imaging modalities, the role they play in the evaluation of disease activity is still controversial. This is partially due to the lack of validated scoring systems.

CONCLUSIONS

Further work is still required to standardize the monitoring strategy and validate the outcome measures in enthesitis-related arthritis.

Discordance between Clinical and Ultrasound Examinations in Juvenile Idiopathic Arthritis: An Experimental Approach

Clinical examination (CE) and musculoskeletal ultrasound (MSUS) of ten joints (knee, ankle, wrist, elbow, II-MCP) and their extra-articular (EA) compartments (tendons and bursae) were performed on 35 consecutive patients with active juvenile idiopathic arthritis (JIA) (active group) to test how the extension of MSUS examinations to EA changes the concordance between MSUS and CE. The overall concordance between CE and MSUS, measured with Cohen’s Kappa (k), was moderate (k = 0.43); the addition of EA MSUS increased the concordance in all joints, with the exclusion of II-MCP (k = 0.49). In the ankle and wrist, the k increase was relevant (k from 0.13 to 0.27 and 0.11 to 0.41). In the active group patients, we observed 44 subclinical synovitis; the number of subclinical synovitis per patient was correlated with JADAS-27 (p = 0.03) and was higher in a control group composed of 15 patients with persistent disease remission (1.3 vs. 0.4 p = 0.03). Our results show that EA compartments should always be evaluated during MSUS. Furthermore, we demonstrate a moderate concordance between CE and MSUS in JIA; the finding of subclinical synovitis is common in patients with active diseases and is related to disease activity.

Ultraschalldiagnostik in der Kinderrheumatologie

Der Artikel gibt einen Überblick zum aktuellen Stand der Ultraschallbefundung in der Kinderrheumatologie und geht insbesondere auf den praktischen Einsatz und die technischen Aspekte der Gelenksonografie ein. Dabei werden auch die wissenschaftlichen Entwicklungen der letzten Jahre zusammengefasst und berücksichtigt. Neben der Gelenksonografie wird die Ultraschalltechnik in der Kinderrheumatologie zunehmend auch auf weitere Körperregionen und -organe ausgeweitet, die für die kinderrheumatologische Diagnostik relevant sind.

Ultrasonography in Pediatric Rheumatology

This review highlights the increasing evidence from the last few years supporting the use of musculoskeletal ultrasonography (MSUS) in the evaluation and management of patients with pediatric rheumatic diseases, particularly focusing on juvenile idiopathic arthritis. Recently developed definitions for the sonographic appearance of healthy and pathologic joints in children are discussed. Further topics explored include how MSUS enhances the diagnosis of inflammatory joint disease (synovitis, enthesitis, tenosynovitis), including the detection of subclinical synovitis. There is a brief summary on the use of ultrasonography in the evaluations of myositis, Sjögren syndrome, and scleroderma.

Development and reliability of a novel ultrasonographic joint-specific scoring system for synovitis with reference atlas for patients with juvenile idiopathic arthritis

Objective

To develop an ultrasonographic image acquisition protocol and a joint-specific scoring system for synovitis with reference atlas in patients with juvenile idiopathic arthritis (JIA) and to assess the reliability of the system.

Methods

Seven rheumatologists with extensive ultrasound experience developed a scanning protocol and a semiquantitative joint-specific scoring system for B-mode (BM) synovitis for the elbow, wrist, metacarpophalangeal 2–3, proximal interphalangeal 2–3, hip, knee, ankle and metatarsophalangeal 2–3 joints. An ultrasonographic reference atlas for BM synovitis, divided in four age groups (2–4, 5–8, 9–12, 13–18 years), and power Doppler (PD) activity was then developed. Reliability was assessed for all joints on still images and in a live exercise including 10 patients with JIA, calculated by intraclass correlation coefficient (ICC) and weighted kappa.

Results

A scanning protocol and scoring system for multiple joints with reference atlas composed of images with four different score levels for BM and PD were developed. Still image scoring for BM synovitis on joint level showed good to excellent intra-reader reliability (ICC/kappa ranges: 0.75–0.95/0.63–0.91) and moderate to excellent inter-reader reliability (ICC/kappa ranges: 0.89–0.99/0.50–0.91). Still image scoring for PD activity showed excellent intra-reader and inter-reader reliability (ICC/kappa: 0.96/0.91 and ICC/kappa: 0.97/0.80, respectively). In the live scoring, inter-reader reliability (ICC/kappa) was moderate to excellent for BM synovitis (0.94/0.51) and PD activity (0.91/0.60).

Conclusion

An ultrasonographic image acquisition protocol and joint-specific scoring system with reference atlas were developed and demonstrated moderate to excellent reliability for scoring of synovitis in patients with JIA. This can be a valuable tool in clinical practice and future research.

Application of the OMERACT synovitis ultrasound scoring system in juvenile idiopathic arthritis: a multicenter reliability exercise

OBJECTIVES

To evaluate the reliability of the OMERACT paediatric ultrasound (US) synovitis definitions and scoring system in JIA.

METHODS

Thirteen sonographers analysed 75 images for the presence/absence of elementary lesions (binary scoring) and for grading synovitis, synovial hypertrophy, effusion and Doppler signals. Static US images of the second metacarpophalangeal joint (MCP-II), wrist, elbow, knee and ankle in JIA patients at different ages and different disease stages were collected with standardized scanning by two experienced sonographers. Intra- and inter-reader reliability were analysed with kappa coefficients.

RESULTS

Intra-reader reliability was good for binary scoring (Cohen's kappa 0.62, range 0.47-0.75), synovitis and synovial hypertrophy; excellent for Doppler signals (quadratic weighted kappa 0.77, 0.66-0.86; 0.76, 0.61-0.84; and 0.87, 0.77-0.94, respectively); and moderate for effusion (0.55, 0.24-0.76). Inter-reader reliability was good for synovitis and synovial hypertrophy (Light's kappa 0.68, 95% CI: 0.61, 0.75 and 0.63, 0.54-0.71, respectively), excellent for Doppler signals (0.85, 95% CI: 0.77, 0.90), and moderate for binary scoring and effusion (0.48, 95% CI: 0.36, 0.64 and 0.49, 0.40-0.60, respectively). We obtained the best scores for the knee (0.71, 0.54-0.85) except for Doppler signals, with reliability higher for MCP-II. We found a trend toward better results in older children.

CONCLUSIONS

This is the first study establishing the reliability of the OMERACT paediatric US synovitis definitions and scoring system in the five most commonly affected joints in JIA. The reliability was good among a large group of sonographers. These results support the applicability of these definitions and scoring system in clinical practice and multicentre studies.

The new role of musculoskeletal ultrasound in the treat-to-target management of juvenile idiopathic arthritis

This article reviews the role of musculoskeletal ultrasound (MSUS) for the diagnosis, monitoring and treat-to-target management of JIA. Technological advancements in MSUS allow more precise evaluation of arthritis, tenosynovitis and enthesitis versus clinical examination alone, which may assist treatment decisions. In adult studies, serum and synovial biomarkers have correlated with MSUS findings. Within paediatric rheumatology, significant developments in the definition of normal and pathology, a necessity for the future integration of MSUS into treat-to-target management, have already been reached or are underway, which in turn could allow tighter control of disease activity and earlier identification of treatment response and failure, bringing the goal of 'precision medicine' closer. Additionally, the utility of MSUS for the evaluation of subclinical disease remains an unexamined area of interest. 'Ultrasound remission' combined with clinical assessment and immunological markers could therefore potentially improve the treat-to-target management of JIA.

Biomarkers of Response to Biologic Therapy in Juvenile Idiopathic Arthritis

Background: Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory arthritis of childhood, characterized by various clinical phenotypes associated with variable prognosis. Significant progress has been achieved with the use of biologic treatments, which specifically block pro-inflammatory molecules involved in the disease pathogenesis. The most commonly used biologics in JIA are monoclonal antibodies and recombinant proteins targeting interleukins 1 (IL-1) and 6 (IL-6), and tumor necrosis factor α (TNF-α). Several biomarkers have been investigated in JIA. Aims: To assess the level of evidence available regarding the role of biomarkers in JIA related to guiding clinical and therapeutic decisions, providing disease prognostic information, facilitating disease activity monitoring and assessing biologic treatment response in JIA, as well as propose new strategies for biologic therapy-related biomarker use in JIA. Methods: We searched PubMed for relevant literature using predefined key words corresponding to several categories of biomarkers to assess their role in predicting and assessing biologic treatment response and clinical remission in JIA. Results: We reviewed serological, cellular, genetic, transcriptomic and imaging biomarkers, to identify candidates that are both well-established and widely used, as well as newly investigated in JIA on biologic therapy. We evaluated their role in management of JIA as well as identified the unmet needs for new biomarker discovery and better clinical applications. Conclusion: Although there are no ideal biomarkers in JIA, we identified serological biomarkers with potential clinical utility. We propose strategies of combining biomarkers of response to biologics in JIA, as well as routine implementation of clinically acceptable imaging biomarkers for improved disease assessment performance.

Ultrasound imaging in paediatric rheumatology

The role of ultrasound imaging in the diagnosis and monitoring of paediatric rheumatic diseases with special emphasis on recent scientific work regarding the evidence base and standardization of this technique is being reviewed. An overview of the most important practical aspects for the use of musculoskeletal ultrasound in a clinical setting is also provided. Huge scientific efforts and advances in recent years illustrate the increasing importance of musculoskeletal ultrasound in pediatric rheumatology. Several studies focused on setting an evidence-based standard for the ultrasound appearance of healthy and normal joints in children of all age groups. Physiologic vascularization and ossification were two main aspects of these studies. Other publications demonstrate that ultrasound imaging is also an important and useful tool to detect pathology as synovitis, tenosynovitis or enthesitis in children and to monitor pediatric patients with rheumatic conditions. Important practical aspects include training in the use of correct ultrasound techniques, as well as knowledge and experience of normal pediatric sonoanatomy and the appearance of pathological findings on ultrasound.

Emergence of Musculoskeletal Ultrasound Use in Pediatric Rheumatology

PURPOSE OF REVIEW

To summarize recent international efforts on standardization and validation of pediatric musculoskeletal ultrasound and determine its role in diagnosis and monitoring of disease in pediatric rheumatology.

RECENT FINDINGS

Over the past decade, significant progress has been made on building the evidence base for musculoskeletal ultrasound in pediatric rheumatology. This includes the clear definition of the sonographic appearance of the normal pediatric joint and enthesis on ultrasonography, definitions for pathology, and the establishment of a specific scoring system for the pediatric knee. Ultrasonography has been shown to have an important role in the detection of subclinical synovitis and can predict flares in children considered to be in remission clinically. Musculoskeletal ultrasound is likely going to play an important role in complementing the clinical exam especially in juvenile idiopathic arthritis. Given the powerful therapeutic tools available, it will support early diagnosis and precisely determine remission status. In a treat to target approach, it will greatly help to define the targets that need to be reached.

Musculoskeletal ultrasound in children: Current state and future directions

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of chronic inflammatory arthritides that if inadequately treated, may be associated with chronic disability and deformity. Early diagnosis and treatment initiation is essential in the management of patients with JIA. Conventional means of evaluation of disease presence, disease activity and response to therapy including physical exam, labs and x-rays are at times limited and may be insufficient in making an accurate assessment. Musculoskeletal ultrasound (MSUS) is a well-established modality that is patient and family-friendly, non-invasive, does not require sedation and can be performed at the bedside in real-time. MSUS offers information that cannot be attained by standard outcome measures, and may help to advance both diagnosis and treatment of patients with JIA ultimately improving patient outcomes. This review explores the background of MSUS and the current evidence to support its potential role as a diagnostic, disease activity monitoring and interventional tool.

Current status and recent advances on the use of ultrasonography in pediatric rheumatic diseases

BACKGROUND

Ultrasonography has become a useful tool in the clinical rheumatology settings in the last two decades, but its use has only recently been explored by pediatric rheumatologists. The aim of this article is to review the literature on the current status and recent advances on the use of ultrasound in pediatric rheumatic diseases.

DATA SOURCES

We have retrieved and reviewed the relevant articles from MEDLINE/PubMed databases published so far, on the applications of ultrasound in juvenile idiopathic arthritis (JIA), systemic lupus erythematosus, dermatomyositis, enthesitis, Sjogren's syndrome, and other rheumatic diseases. In addition, articles on novel ultrasound imaging technology of potential use in pediatric rheumatology are also reviewed.

RESULTS

In JIA, ultrasound can be used to detect subclinical synovitis, to improve the classification of patients in JIA subtypes, to capture early articular damage, to monitor treatment response, and to guide intraarticular injections. Ultrasound is also considered useful in other rheumatic disorders for the evaluation of musculoskeletal symptoms, assessment of parotid gland pathology, and measurement of skin thickness and pathology. Novel ultrasound techniques developed to augment the functionality of ultrasonography may also be applicable in pediatric rheumatic disorders.

CONCLUSIONS

Ultrasound shows great promise in the assessment and management of children with rheumatologic disorders. However, standardization and validation of ultrasound in healthy children and in patients with rheumatic diseases are still needed.

Novel Ultrasound Image Acquisition Protocol and Scoring System for the Pediatric Knee

OBJECTIVE

The use of musculoskeletal ultrasound is increasing among pediatric rheumatologists. Reliable scoring systems are needed for the objective assessment of synovitis. The aims of this study were to create a standardized and reproducible image acquisition protocol for B-mode and Doppler ultrasound of the pediatric knee, and to develop a standardized scoring system and determine its reliability for pediatric knee synovitis.

METHODS

Six pediatric rheumatologists developed a set of standard views for knee assessment in children with juvenile arthritis. Subsequently, a comprehensive literature review, practical exercises, and a consensus process were performed. A scoring system for both B-mode and Doppler was then developed and assessed for reliability. Interreader reliability or agreement among a total of 16 raters was determined using 2-way single-score intraclass correlation coefficient (ICC) analysis.

RESULTS

Twenty-one views to assess knee arthritis were initially identified. Following completion of practical exercises and subsequent consensus processes, 3 views in both B-mode and Doppler were selected: suprapatellar longitudinal and medial/lateral parapatellar transverse views. Several rounds of scoring and modifications resulted in a final ICC of suprapatellar view B-mode 0.89 (95% confidence interval [95% CI] 0.86-0.92) and Doppler 0.55 (95% CI 0.41-0.69), medial parapatellar view B-mode 0.76 (95% CI 0.68-0.83) and Doppler 0.75 (95% CI 0.66-0.83), and lateral parapatellar view B-mode 0.82 (95% CI 0.75-0.88) and Doppler 0.76 (95% CI 0.66-0.84).

CONCLUSION

A novel B-mode and Doppler image acquisition and scoring system for assessing synovitis in the pediatric knee was successfully developed through practical exercises and a consensus process. Study results demonstrate overall good-to-excellent reliability.

Age dependent ultrasound B-mode findings of the elbow joint in healthy children and adolescents

Due to maturation of joints, various changes take place, not only in the field of paediatric rheumatology but also in paediatric orthopaedics musculoskeletal ultrasound plays an important role in both the diagnosis and the follow-up of diseases in this field. To differentiate between physiological and pathological findings, the knowledge of reference values of joint structures is indispensable. The objective was to define B-mode ultrasound age- and sex-related reference values for the elbow joint in healthy children and adolescents during maturation. In a cross-sectional, multicentre ultrasound study we examined both sides of the elbow joints of 437 healthy children and adolescents (194 boys/243 girls) being between one and less than 18 years old. The children were classified into six equal age groups and divided according to their gender. We measured the distance between the outer margin of the joint capsule and the bone surface to define the bone-capsule distance (BCD), the thickness of the joint cartilage as well as the thickness of the joint capsule. The bone-capsule junction zone and the shape of the joint capsule were analysed qualitatively. The bone capsule distance and the capsule thickness increased with age. In contrast, the joint cartilage thickness decreased. In most cases the junction zone was peaked. The joint capsule showed mostly a concave shape. Intra- and interobserver reliabilities were good. We propose B-mode ultrasound age- and sex-related reference values for the elbow joint in a large number of healthy children and adolescents for the first time. By applying these standard values to the ultrasound examination of the elbow joint, it may be possible to achieve greater certainty in the diagnosis of pathological processes.

The role of imaging in juvenile idiopathic arthritis

INTRODUCTION

The prognosis of juvenile idiopathic arthritis (JIA) has changed dramatically due to the availability of novel drugs. Prompt diagnosis and treatment are essential to prevent permanent joint damage. As a result, methods to improve JIA diagnosis and prognosis are of high priority to tailor treatment strategies and maximize their efficacy. Musculoskeletal ultrasound and magnetic resonance imaging are more sensitive than clinical examination and radiography in the detection of joint involvement and might play a substantial role to optimize the management of JIA. Areas covered: This review compiles an inventory of potential uses of imaging studies in the modern practice of pediatric rheumatology, together with a critical analysis of the major challenges that are still to be addressed. Imaging appearance of normal growth-related changes of the musculoskeletal system will be discussed. Expert commentary: Knowledge of the evolving patterns of skeletal maturity is paramount to define pathological findings and avoid misinterpretations. Establishing a novel radiological algorithm for a rational use of imaging in JIA is of high priority to allow a speedier integration of imaging into the clinical workflow and decision-making process.

Juvenile idiopathic arthritis - the role of imaging from a rheumatologist's perspective

Alongside recent advances in treatment strategies for juvenile idiopathic arthritis (JIA), paediatric rheumatologists have taken increasing interest in the use of imaging. Magnetic resonance imaging (MRI) and musculoskeletal ultrasound, by providing more detailed information on disease activity than clinical examination and conventional radiography (CR), have become helpful diagnostic and managerial tools. The growing skeleton, however, with changing appearances over time, is still challenging in the establishment of valid scoring systems for pathological changes. Defining child- and age-specific reference standards is therefore a highly prioritized issue. The aim of this article is to raise awareness among radiologists of the substantial role that imaging can play to optimize the management of JIA patients and to describe the state-of-the-art validation process of imaging as an outcome measure. A closer collaboration between radiologists and pediatric rheumatologists is crucial to define a scheduled workflow for imaging in JIA.

Amendment of the OMERACT ultrasound definitions of joints' features in healthy children when using the DOPPLER technique

BACKGROUND

Recently preliminary ultrasonography (US) definitions, in B mode, for normal components of pediatric joints have been developed by the OMERACT US group. The aim of the current study was to include Doppler findings in the evaluation and definition of normal joint features that can be visualized in healthy children at different age groups.

METHODS

A multistep approach was used. Firstly, new additional definitions of joint components were proposed during an expert meeting. In the second step, these definitions, along with the preliminary B-mode-US definitions, were tested for feasibility in an exercise in healthy children at different age groups. In the last step, a larger panel of US experts were invited to join a web-based consensus process in order to approve the developed definitions using the Delphi methodology. A Likert scale of 1-5 was used to assess agreement.

RESULTS

Physiological vascularity and fat pad tissue were identified and tested as two additional joint components in healthy children. Since physiological vascularity changes over the time in the growing skeleton, the final definition of Doppler findings comprised separate statements instead of a single full definition. A total of seven statements was developed and included in a written Delphi questionnaire to define and validate the new components. The final definitions for fat pad and physiological vascularity agreed by the group of experts reached 92.9% and 100% agreement respectively in a web survey.

CONCLUSION

The inclusion of these two additional joints components which are linked to detection of Doppler signal in pediatric healthy joints will improve the identification of abnormalities in children with joint pathologies.

US Evaluation of Juvenile Idiopathic Arthritis and Osteoarticular Infection

Juvenile idiopathic arthritis (JIA) and osteoarticular infection can cause nonspecific articular and periarticular complaints in children. Although contrast material-enhanced magnetic resonance imaging is the reference standard imaging modality, musculoskeletal ultrasonography (US) is emerging as an important adjunct imaging modality that can provide valuable information relatively quickly without use of radiation or the need for sedation. However, diagnostic accuracy requires a systemic approach, familiarity with various US techniques, and an understanding of maturation-related changes. Specifically, the use of dynamic, Doppler, and/or multifocal US assessments can help confirm sites of disease, monitor therapy response, and guide interventions. In patients with JIA, ongoing synovial inflammation can lead to articular and periarticular changes, including synovitis, tenosynovitis, cartilage damage, bone changes, and enthesopathy. Although these findings can manifest in adult patients with rheumatoid arthritis, important differences and pitfalls exist because of the unique changes associated with an immature and maturing skeleton. In patients who are clinically suspected of having osteoarticular infection, the inability of US to evaluate the bone marrow decreases its sensitivity. Therefore, the US findings should be interpreted with caution because juxtacortical inflammation is suggestive, but neither sensitive nor specific, for underlying osteomyelitis. Similarly, the absence of a joint effusion makes septic arthritis extremely unlikely but not impossible. US findings of JIA and osteoarticular infection often overlap. Although certain clinical scenarios, laboratory findings, and imaging appearances can favor one diagnosis over the other, fluid analysis may still be required for definitive diagnosis and optimal treatment. US is the preferred modality for fluid aspiration and administering intra-articular corticosteroid therapy. ^© RSNA, 2017.

Preliminary Definitions for the Sonographic Features of Synovitis in Children

OBJECTIVE

Musculoskeletal ultrasonography (US) has the potential to be an important tool in the assessment of disease activity in childhood arthritides. To assess pathology, clear definitions for synovitis need to be developed first. The aim of this study was to develop and validate these definitions through an international consensus process.

METHODS

The decision on which US techniques to use and the components to be included in the definitions, as well as the final wording, were developed by 31 US experts in a consensus process. A Likert scale of 1-5 (where 1 = complete disagreement and 5 = complete agreement) was used. A minimum of 80% of the experts scoring 4 or 5 was required for final approval. The definitions were then validated on 120 standardized US images of the wrist, metacarpophalangeal joints, and tibiotalar joints, displaying various degrees of synovitis at various ages.

RESULTS

B-mode and Doppler should be used for assessing synovitis in children. A US definition of the various components (i.e., synovial hypertrophy, effusion, and Doppler signal within the synovium) was developed. The definition was validated on still images with a median of 89% of participants (range 80-100) scoring it as 4 or 5 on a Likert scale.

CONCLUSION

US definitions of synovitis and its elementary components covering the entire pediatric age range were successfully developed through a Delphi process and validated in a web-based still-images exercise. These results provide the basis for the standardized US assessment of synovitis in clinical practice and research.

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.

Imaging in paediatric rheumatology: Is it time for imaging?

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of arthritides characterized by chronic synovial inflammation that can lead to structural damage. The main objective of JIA therapies is to induce disease control to avoid disability in childhood. The advances in therapeutic effectiveness have created a need to search for imaging tools that describe more precisely disease activity in children with JIA. Musculoskeletal ultrasound and magnetic resonance imaging have demonstrated to be more sensitive than clinical examination in early detection of synovitis. These modalities can detect both inflammatory and destructive changes. The unique characteristics of the growing skeleton and a scarce validation of imaging in children result in important challenges in evaluating paediatric population. This review describes indications and limitations of these imaging techniques and suggests some advices for a rational use in the management of JIA in clinical practice.

Toward Standardized Musculoskeletal Ultrasound in Pediatric Rheumatology: Normal Age-Related Ultrasound Findings

OBJECTIVE

The Outcome Measures in Rheumatology Ultrasound Task Force has recently started to work on the validation and standardization of musculoskeletal ultrasound (MSUS) examination in children in order to improve its applicability to joint examination.

METHODS

This was a prospective multicenter study performed by 4 experts in pediatric MSUS, who independently collected representative images using predefined scanning procedures of 4 joints (knee, ankle, wrist, and second metacarpophalangeal joint) in different predefined age groups. Researchers were allowed to use their own settings (B-mode and Doppler) in order to get the best quality image and highest sensitivity for low blood flow. Images were evaluated for quality parameters and an atlas was created with the best images. An equipment comparative study was performed by a single examiner using 2 different types of machines.

RESULTS

Sixty-four healthy children were scanned. The quality of evaluated images, obtained by predefined scanning positions, was highly comparable among the examiners. The B-mode images clearly showed age-related variations of joint findings, while Doppler images showed the presence of blood flow, particularly within the epiphyseal cartilage of the children at a younger age. There was a high to good level of consistency between images obtained from the 2 different ultrasound machines.

CONCLUSION

The study shows a systematic method for ultrasound examination of children at different age groups. Additionally, a baseline collection of images was developed, showing blood vessels in the joints examined. The present study could provide a framework for ongoing MSUS studies as well as for clinical practice in pediatric rheumatology.

Ultrasound in juvenile idiopathic arthritis

BACKGROUND

In the recent years, musculoskeletal ultrasound (MSUS) has been regarded as especially promising in the assessment of juvenile idiopathic arthritis (JIA), as a reliable method to precisely document and monitor the synovial inflammation process.

MAIN CONTENT

MSUS is particularly suited for examination of joints in children due to several advantages over other imaging modalities. Some challenges should be considered for correct interpretation of MSUS findings in children, due to the peculiar features of the growing skeleton. MSUS in JIA is considered particularly useful for its ability to detect subclinical synovitis, to improve the classification of patients in JIA subtypes, for the definition of remission, as guidance to intraarticular corticosteroid injections and for capturing early articular damage. Current evidence and applications of MSUS in JIA are documented by several authors. Recent advances and insights into further investigations on MSUS in healthy children and in JIA patients are presented and discussed in the present review.

CONCLUSIONS

MSUS shows great promise in the assessment and management of children with JIA. Nonetheless, anatomical knowledge of sonographic changes over time, underlying immunopathophysiology, standardization and validation of MSUS in healthy children and in patients with JIA are still under investigation. Further research and educational efforts are required for expanding this imaging modality to more clinicians in their daily practice.

Ultrasonography in pediatric rheumatology in Latin America. Expanding the frontiers

For the past two decades, musculoskeletal ultrasonography (MSKUS) has developed exponentially and has become an essential tool in rheumatology practice. This development has been far more limited in pediatric rheumatology which is partially related to deficits in the evidence base. Many studies have shown that MSKUS is more sensitive than the clinical examination for detecting synovitis and enthesitis in adults. At the same time, there is a lack of studies demonstrating its validity, reliability, and reproducibility in pediatric rheumatology. In addition, clear definitions for the normal pediatric joint and enthesis as well as various findings in pathology associated with juvenile idiopathic arthritis (JIA) and juvenile spondyloarthritis (JSpA) have only started to emerge. Most of this work is being done through the Outcome Measurement in Rheumatology Clinical Trials (OMERACT) ultrasound pediatric task force but the Pan American League of Associations for Rheumatology (PANLAR) US Pediatric Task Force is also working on validating MSKUS in children. In addition, several MSKUS courses for pediatric rheumatologists have been offered in Latin American countries; these will not only complement the scientific work pediatric-specific ultrasonography training, but also represents an essential component for the successful implementation of this technique into daily practice as well.

EULAR-PReS points to consider for the use of imaging in the diagnosis and management of juvenile idiopathic arthritis in clinical practice

To develop evidence based points to consider the use of imaging in the diagnosis and management of juvenile idiopathic arthritis (JIA) in clinical practice. The task force comprised a group of paediatric rheumatologists, rheumatologists experienced in imaging, radiologists, methodologists and patients from nine countries. Eleven questions on imaging in JIA were generated using a process of discussion and consensus. Research evidence was searched systematically for each question using MEDLINE, EMBASE and Cochrane CENTRAL. Imaging modalities included were conventional radiography, ultrasound, MRI, CT, scintigraphy and positron emission tomography. The experts used the evidence obtained from the relevant studies to develop a set of points to consider. The level of agreement with each point to consider was assessed using a numerical rating scale. A total of 13 277 references were identified from the search process, from which 204 studies were included in the systematic review. Nine points to consider were produced, taking into account the heterogeneity of JIA, the lack of normative data and consequent difficulty identifying pathology. These encompassed the role of imaging in making a diagnosis of JIA, detecting and monitoring inflammation and damage, predicting outcome and response to treatment, use of guided therapies, progression and remission. Level of agreement for each proposition varied according to the research evidence and expert opinion. Nine points to consider and a related research agenda for the role of imaging in the management of JIA were developed using published evidence and expert opinion.

Definitions for the sonographic features of joints in healthy children

OBJECTIVE

Musculoskeletal ultrasonography (US) has potential in the assessment of disease activity and structural damage in childhood arthritides. In order to assess pathology, the US characteristics of joints in healthy children need to be defined first. The aim of this study was to develop definitions for the various components of the normal pediatric joint.

METHODS

The definitions were developed by an expert group and applicability was assessed on a collection of standardized scans of the knee and ankle joints by scoring the scans on a Likert scale. The definitions were then modified and applicability was reassessed before sending the definitions for approval to a larger panel of experts. A final scoring on stored images of all relevant joints at different ages followed.

RESULTS

Five definitions were developed addressing the articular bone, cartilage, joint capsule, epiphyseal ossification center, and synovial membrane. In total, 224 US images of knees and ankles were acquired, of which 172 were selected for scoring. An agreement of ≥80% was not met for any of the definitions, but after modifications, 81-97% agreement was reached. This version of the definitions was approved by 15 US experts. In the final validation exercise, all definitions reached an agreement of ≥80% for the shoulder, elbow, wrist, metacarpophalangeal hip, knee, ankle and metatarsophalangeal joint.

CONCLUSION

US definitions for the normal pediatric joint were successfully developed through a Delphi process and validated in a practical exercise. These results provide the basis to develop definitions for pathology and to support the standardized use of US in pediatric rheumatology.

Application of high frequency color Doppler ultrasound in the monitoring of rheumatoid arthritis treatment

The aim of the present study was to explore the use of high frequency color Doppler ultrasound to measure synovial thickness and blood flow to assess the therapeutic value of the recombinant human tumor necrosis factor (TNF) II receptor antibody fusion protein in rheumatoid arthritis (RA) treatment. A total of 36 clinically-diagnosed patients with RA were treated with methotrexate tablets or the recombinant TNF-receptor antibody fusion protein for 24 weeks. Joint synovial thickness and synovial blood flow integrity were monitored by high frequency color Doppler in the second metacarpophalangeal joint in one hand. The correlation of the erythrocyte sedimentation rate, C-reactive protein (CRP) and 28-joint disease activity score (DAS28) with the ultrasound parameters were analyzed. Metacarpophalangeal second joint 2 (MCP2) synovial thickness, wrist joint synovial thickness and MCP2 synovial blood flow, prior and subsequent to the treatment, have a high correlation with DAS28 (P<0.05), and the MCP2 synovial blood flow integral has a strong correlation with CRP. Evaluating the wrist joint synovial thickness and synovial integrity of the second metacarpophalangeal joint using high frequency ultrasound detection can effectively evaluate the disease status in patients with RA. This procedure is potentially valuable as a means of evaluating the curative effects of RA treatments.

Disease of the year: juvenile idiopathic arthritis-associated uveitis--classification and diagnostic approach

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease and the most common systemic association of uveitis in children. JIA is subdivided into seven clinically more homogeneous subtypes, using the International League of Associations for Rheumatology (ILAR) classification system: systemic arthritis, oligoarthritis, rheumatoid factor (RF)-negative polyarthritis, RF-positive polyarthritis, psoriatic arthritis, enthesitis-related arthritis, and undifferentiated arthritis. Uveitis is very rare in patients with systemic onset JIA and in patients with juvenile-onset rheumatoid arthritis. Patients with early-onset antinuclear antibody (ANA)-positive oligoarticular JIA have the highest risk of developing chronic iridocyclitis. Ocular involvement in enthesitis-related arthritis is characterized by recurrent acute symptomatic iridocyclitis. The diagnosis and differential diagnosis of JIA are based on history, physical examination, and laboratory investigations, including complete blood count, acute-phase reactants, ANA, RF, HLA-B27, and musculoskeletal imaging studies. Recent studies have revealed distinct gene expression profiles that may be useful in the diagnosis, classification, and follow-up of JIA patients.