The early magnetic resonance imaging features of the knee in juvenile idiopathic arthritis

Measuring synovial thickness on knee MRI in pediatric patients with arthritis: is contrast necessary?

BACKGROUND

The use of contrast-enhanced imaging has long been standard for magnetic resonance imaging (MRI) assessments of synovitis in juvenile idiopathic arthritis (JIA). However, advancements in MRI technology have allowed for reliable identification of synovium without contrast.

OBJECTIVE

To assess the equivalence of unenhanced MRI with contrast-enhanced MRI in evaluating synovial thickness.

MATERIALS AND METHODS

This is an institutional review board approved, retrospective study performed in a tertiary children's hospital. Pediatric JIA patients under 21 years old were included who underwent knee MRI scans (1.5 T or 3 T) without and with contrast between January 2012 and January 2022. Two radiologists independently measured synovial thickness at 6 knee sites on contrast-enhanced and unenhanced sequences. Numerical measurements and ordinal scores based on juvenile idiopathic arthritis magnetic resonance imaging scoring (JAMRIS) system were recorded, and tests of equivalence were conducted, as well as between-reader and within-reader reliability by concordance correlation coefficient (CCC). All tests were considered significant at the 5% level.

RESULTS

A total of 38 studies from 35 patients (25 females, median age 14 years; interquartile range 7 to 15.7) were included. Equivalence was demonstrated at each of the 6 sites for both continuous measurements (P-values < 0.05) and ordinal scores (P-values < 0.05) based on the average over readers. Within-reader reliability was moderate to high (CCC 0.50-0.89), except for the cruciate ligaments site. Averaged over the 6 sites, reliability between readers was low for unenhanced (CCC 0.47, with 95% CI: [0.41, 0.53]) and moderate for contrast-enhanced (CCC 0.64, with 95% CI: [0.59, 0.69]) sequences.

CONCLUSION

Unenhanced knee MRI is equivalent to contrast-enhanced MRI in assessment of synovial thickness using conventional MRI sequences. Contrast material helped improve inter-reader reliability.

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.

Current status of MR imaging of juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic arthropathy in the pediatric population. Although the diagnosis is essentially clinical for many affected joints, MR imaging has become an important tool for the assessment of joints that are difficult to evaluate clinically, such as temporomandibular and sacroiliac joints, and for screening of inflammatory changes in the entire body by whole body MRI (WBMRI) assessment. The utilization of MR imaging is challenging in the pediatric population given the need for discrimination between pathological and physiological changes in the growing skeleton. Several multicentric multidisciplinary organizations have made major efforts over the past decades to standardize, quantify, and validate scoring systems to measure joint changes both cross-sectionally and longitudinally according to rigorous methodological standards. In this paper, we (1) discuss current trends for the diagnosis and management of JIA, (2) review challenges for detecting real pathological changes in growing joints, (3) summarize the current status of standardization of MRI protocols for data acquisition and the quantification of joint pathology in JIA by means of scoring systems, and (4) outline novel MR imaging techniques for the evaluation of anatomy and function of joints in JIA. Optimizing the role of MRI as a robust biomarker and outcome measure remains a priority of future research in this field.

Prolonged time between intravenous contrast administration and image acquisition results in increased synovial thickness at magnetic resonance imaging in patients with juvenile idiopathic arthritis

BACKGROUND

Post-contrast synovial thickness measurement is necessary for scoring disease activity in juvenile idiopathic arthritis (JIA). However, the timing of post-contrast sequences varies widely among institutions. This variation in timing could influence thickness measurements.

OBJECTIVE

To measure thickness of the synovial membrane on early and late post-contrast knee magnetic resonance (MR) images of patients with JIA.

MATERIALS AND METHODS

Dynamic contrast-enhanced T1-weighted knee MR images of 53 children with JIA with current or past knee arthritis were used to study synovial thickness at time point 1 (about 1 min) and time point 2 (about 5 min after contrast administration). Two experienced readers, who were blinded for the time point, independently measured synovial thickness at a predefined, marked location in the patellofemoral compartment on randomized images. Synovial thickness at the two time points was compared using the Wilcoxon signed rank test. Repeatibility of the synovial thickness measurements was studied using intraclass correlation coefficients and Bland-Altman plots.

RESULTS

Median synovial thickness of the 53 patients (median age: 13.5 years, 59% female) increased with prolonged post-contrast interval with a synovial thickness of 1.4 mm at time point 1 and a synovial thickness of 1.5 mm at time point 2 (P<0.001). Repeated synovial thickness measurements showed an intraclass correlation coefficient (ICC) of 0.75, P<0.05 for time point 1 and an ICC of 0.91, P<0.05 for time point 2.

CONCLUSION

Post-contrast synovial membrane thickness measurements are time-dependent. Therefore, standardization of post-contrast image acquisition timing is important to achieve consistent grading of synovial inflammation.

Anti-citrullinated peptide antibodies are the strongest predictor of clinically relevant radiographic progression in rheumatoid arthritis patients achieving remission or low disease activity: A post hoc analysis of a nationwide cohort in Japan

Objectives

To determine prognostic factors of clinically relevant radiographic progression (CRRP) in patients with rheumatoid arthritis (RA) achieving remission or low disease activity (LDA) in clinical practice.

Methods

Using data from a nationwide, multicenter, prospective study in Japan, we evaluated 198 biological disease-modifying antirheumatic drug (bDMARD)-naïve RA patients who were in remission or had LDA at study entry after being treated with conventional synthetic DMARDs (csDMARDs). CRRP was defined as the yearly progression of modified total Sharp score (mTSS) >3.0 U. We performed a multiple logistic regression analysis to explore the factors to predict CRRP at 1 year. We used receiver operating characteristic (ROC) curve to estimate the performance of relevant variables for predicting CRRP.

Results

The mean Disease Activity Score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR) was 2.32 ± 0.58 at study entry. During the 1-year observation, remission or LDA persisted in 72% of the patients. CRRP was observed in 7.6% of the patients. The multiple logistic regression analysis revealed that the independent variables to predict the development of CRRP were: anti-citrullinated peptide antibodies (ACPA) positivity at baseline (OR = 15.2, 95%CI 2.64–299), time-integrated DAS28-ESR during the 1 year post-baseline (7.85-unit increase, OR = 1.83, 95%CI 1.03–3.45), and the mTSS at baseline (13-unit increase, OR = 1.22, 95%CI 1.06–1.42).

Conclusions

ACPA positivity was the strongest independent predictor of CRRP in patients with RA in remission or LDA. Physicians should recognize ACPA as a poor-prognosis factor regarding the radiographic outcome of RA, even among patients showing a clinically favorable response to DMARDs.

Arthroscopy of the Temporomandibular Joint in Patients With Juvenile Idiopathic Arthritis

PURPOSE

The early diagnosis of temporomandibular joint (TMJ) involvement in patients with juvenile idiopathic arthritis (JIA) before joint destruction and growth disturbances could allow for interceptive treatment. The purpose of this article is to report early TMJ arthroscopic findings in patients with JIA.

PATIENTS AND METHODS

This was a case series of 3 patients with JIA treated at the Emory University Division of Oral and Maxillofacial Surgery from July 2011 through December 2012. Patients were included if they had a confirmed diagnosis of JIA, did not respond to anti-rheumatologic medication, and had TMJ pain or limited mouth opening. All patients underwent TMJ arthroscopy with an injection of triamcinolone hexacetonide. Demographics, medical history, magnetic resonance imaging findings, arthroscopic findings, and postoperative course were reported.

RESULTS

Three female patients (mean age, 12.5 yr; 5 joints) underwent arthroscopy. Arthroscopic findings consisted of mild to moderate synovitis and grade 2 to 4 chondromalacia with or without fibrosis. Postoperatively, all patients had improvement in pain and mouth opening.

CONCLUSIONS

There was a positive correlation between duration of JIA activity in the TMJ and severity of arthroscopic findings. Arthroscopic lysis and lavage combined with triamcinolone hexacetonide injection resulted in improvement in pain and range of motion.

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.

Cartilage Thickness of the Knee Joint in Juvenile Idiopathic Arthritis: Comparative Assessment by Ultrasonography and Magnetic Resonance Imaging

Objective.

The functional disability experienced in juvenile idiopathic arthritis (JIA) is primarily caused by joint effusion, synovial membrane hypertrophy, and periarticular soft tissue edema, leading to the degeneration of the osteocartilaginous structures because of the inflammatory process in the synovium. The ability to visualize the inflammatory changes and hence the ensuing osteocartilaginous degeneration is, therefore, of great importance in pediatric rheumatology. Ultrasonography (US) has been validated as a tool for measuring cartilage thickness in healthy children and, previously, we have found good agreement with the measures obtained by magnetic resonance imaging (MRI). Our aim is to validate and compare US with MRI measurements of distal femoral cartilage thickness in the knee joint at the medial condyle, lateral condyle, and intercondylar spots in children with JIA, and to locate the best spot for imaging comparisons.

Methods.

One knee from each of 23 children with oligoarticular JIA were investigated by both MRI and US. Outcome measures of imaging procedures were distal femoral cartilage thickness.

Results.

We found a high level of agreement between MRI and US measurements of mean cartilage thickness, and Rho values between modalities were high (between 0.70 and 0.86, p < 0.05 for all). We found a thinner cartilage thickness at the medial condyle in comparison to the other investigated points. Evaluation of anatomical landmarks for optimal measurement of cartilage thickness was found to be the intercondylar spot, which was easier to locate in addition to a smaller variance around the mean for that anatomical measuring point.

Conclusion.

US measurements of distal femoral cartilage thickness are highly correlated to MRI measurements. The intercondylar notch of the distal femoral cartilage may be the best anatomical point for cartilage thickness measurements of the knee. US is a reliant and nonexpensive, non-invasive modality for visualization of childhood femoral cartilage.

Distribution pattern of MRI abnormalities within the knee and wrist of juvenile idiopathic arthritis patients: signature of disease activity

OBJECTIVE

The aim of this study in clinically active juvenile idiopathic arthritis (JIA) was to assess the frequency and distribution pattern of synovitis as hallmark of disease and additional soft-tissue and bony abnormalities on MRI in the knee and wrist as two target joints.

MATERIALS AND METHODS

MRI datasets of 153 clinically active JIA patients (110 with knee and 43 with wrist involvement) were evaluated independently by two readers for the presence of literature-based imaging features: "synovial hypertrophy," "bone marrow changes," "bone erosions," "tenosynovitis" (only in the wrist), and "cartilage lesions" (only in the knee) in accordance with validated definitions and scoring locations.

RESULTS

Synovial hypertrophy was most frequently observed--both in the knee and in the wrist (61.8-65.1% of cases). For the knee, the most frequently involved locations were the cruciate ligaments (46/183 locations [25.1%] affected with synovial hypertrophy) and medial patella (18/62 locations [29.0%] with bone marrow changes). Cartilage lesions and bone erosions were rare (5.5-7.3% of cases). For the wrist, most frequently involved were the radiocarpal joint (21/64 locations [32.8%] with synovial hypertrophy), lunate (7/46 locations [15.2%] with bone marrow changes), and capitate or triquetrum (6/28 locations [21.4%] with bone erosions). Tenosynovitis was a common wrist-specific feature (46.5% of cases). MRI showed no abnormalities in a subgroup of patients with clinically active knee (23.6%) and wrist (16.3%) involvement.

CONCLUSION

The distribution pattern of MRI abnormalities in the knee and wrist of active JIA patients provides a practical tool to detect a signature of JIA disease activity in target joints.

Selecting magnetic resonance imaging (MRI) outcome measures for juvenile idiopathic arthritis (JIA) clinical trials: first report of the MRI in JIA special interest group

Recent advances in magnetic resonance imaging (MRI) techniques have substantially improved the evaluation of joint pathologies in juvenile idiopathic arthritis (JIA). Because of the current availability of highly effective antirheumatic therapies and the unique and useful features of MRI, there is a growing need for an accurate and reproducible MRI assessment scoring system for JIA, such as the rheumatoid arthritis MRI Scoring (RAMRIS) for patients with rheumatoid arthritis (RA). To effectively evaluate the efficacy of treatment in clinical research trials, we need to develop and validate scoring methods to accurately measure joint outcomes, standardize imaging protocols for data acquisition and interpretation, and create imaging atlases to differentiate physiologic and pathologic joint findings in childhood and adolescence. Such a standardized, validated, JIA-MRI scoring method could be used as an outcome measure in clinical trials.

MRI of pediatric patients: Part 2, normal variants and abnormalities of the knee

OBJECTIVE

The purpose of this article is to discuss MRI of the pediatric knee and familiarize the reader with conditions encountered in the pediatric population. Clinical scenarios are included to convey important concepts and to orient the learner to normal variants and abnormalities of the pediatric knee. The conditions discussed include, but are not limited to, distal femoral metaphysial irregularity, isolated popliteus tendon avulsion, juvenile idiopathic arthritis, and discoid meniscus.

CONCLUSION

The knee is the joint that is most commonly imaged by MRI in children. Injury patterns and signs of other pathologic processes seen in skeletally immature patients are different from those seen in adults. Interpreting pediatric knee MRI studies may be a challenge for those unfamiliar with the evolving patterns of normal development and of the signs of conditions that are more prevalent in children. Through case scenarios, this article describes and provides images that depict conditions commonly encountered in the pediatric knee. Most of the described normal findings and abnormalities are more prevalent in the pediatric population than in adults, and a few of the conditions are, in fact, unique to pediatric patients.

Epidemiology, pathogenesis, and imaging of arthritis in children

Juvenile idiopathic arthritis is a broad term used to describe a series of chronic arthritis occurring in children younger than 16 years of age. Even though the cause is not fully understood, several clues regarding the pathogenesis have been found. Diagnosis of the different types of juvenile idiopathic arthritis is made clinically, and imaging plays a role in answering specific questions pertaining to disease classification, staging, and outcome of treatment options.

Spectrum of synovial pathologies: a pictorial assay

The synovium, a specialized vascular tissue, lines the diarthrodial joints, bursae, and tendon sheaths of the body. It helps in nourishment of articular structures. The synovium is affected by a variety of disorders that can be either localized or systemic. Although normal synovium is barely perceptible on magnetic resonance imaging, it provides an excellent imaging modality for the evaluation of pathologic processes involving the synovium. The pathologic processes affecting the synovium include 1 of the following etiologies: inflammatory, infectious, degenerative, traumatic, or neoplastic and tumor-like conditions. In this article, we discuss the magnetic resonance imaging technique and the sequences used in the evaluation of synovial pathologies and review the characteristic imaging findings of specific conditions thus narrowing the differential diagnoses.

Increasing feasibility and patient comfort of MRI in children with juvenile idiopathic arthritis

BACKGROUND

MRI is the most sensitive imaging modality in juvenile idiopathic arthritis (JIA), but has practical limitations. Optimizing the scanning protocol is, therefore, necessary to increase feasibility and patient comfort.

OBJECTIVE

To determine the feasibility of bilateral non-contrast-enhanced open-bore MRI of knees and to assess the presence of literature-based MRI features in unsedated children with JIA.

MATERIALS AND METHODS

Children were classified into two clinical subgroups: active arthritis (group 1; n = 29) and inactive disease (group 2; n = 18). MRI features were evaluated using a literature-based score, comprising synovial hypertrophy, cartilage lesions, bone erosions, bone marrow changes, infrapatellar fat pad heterogeneity, effusion, tendinopathy and popliteal lymphadenopathy.

RESULTS

The MRI examination was successfully completed in all 47 children. No scan was excluded due to poor image quality. Synovial hypertrophy was more frequent in group 1 (36.2%), but was also seen in 19.4% of the knees in group 2. Infrapatellar fat pad heterogeneity was more prevalent in group 2 (86.1%; P = 0.008). Reproducibility of the score was good (Cohen kappa, 0.49-0.96).

CONCLUSION

Bilateral non-contrast-enhanced open-bore knee MRI is feasible in the assessment of disease activity in unsedated children with JIA. Signs differing among children with active and inactive disease include infrapatellar fat pad heterogeneity and synovial hypertrophy.

Detection of Active Disease in Juvenile Idiopathic Arthritis: Sensitivity and Specificity of the Physical Examination vs Ultrasound

Objective.

To determine sensitivity and specificity of the physical examination (PE) for identifying synovitis in the knee and ankle joints of children with juvenile idiopathic arthritis (JIA), and to identify cases in which ultrasound (US) screening augments the PE.

Methods.

Nineteen patients with JIA were referred for US. Both knees and ankles were examined using US with and without power Doppler. Active arthritis on PE was defined as (1) non-bony swelling or (2) limitation of motion with either pain on motion or tenderness to palpation. Active arthritis on US was defined as synovial hyperplasia, effusion, or increased vascularity on power Doppler scan.

Results.

There was agreement between US and PE in 75% of cases. PE was 64% sensitive and 86% specific for identifying active arthritis. PE was 100% specific if (1) the patient was positive for both PE criteria or (2) if arthritis was present on PE in the knees. When the PE was negative and the US was positive, 21.4% developed active disease on PE within 6 months. In cases where the PE was positive and US was negative, the joint involved was most often the ankle and frequently the subtalar joint.

Conclusion.

PE is neither highly sensitive nor specific for identifying active synovitis when compared to US, and screening with US can identify subclinical disease. In joints with both non-bony swelling and limitation of motion with pain on motion or tenderness, and in the knee joint, little additional information is gained by US. This has implications for classification and treatment of JIA.

Misdiagnosis of knee venous malformation as juvenile idiopathic arthritis

BACKGROUND

Initial clinical presentation of knee venous malformation can mimic that of juvenile idiopathic arthritis, posing a diagnostic dilemma. In this communication, we discuss the diagnostic challenges encountered in children with venous malformation of the knee who were misdiagnosed as having juvenile idiopathic arthritis. We highlight the clinical and imaging differences between these 2 disorders with the goal of preventing these diagnostic pitfalls in the future.

METHODS

We conducted a comprehensive search of our databases at Children's Hospital Boston over the last 11 years (1999 to 2009) for patients with venous malformation of the knee who were initially given the diagnosis of juvenile idiopathic arthritis. A retrospective review of the medical records, photographs, and imaging studies was performed.

RESULTS

Of the 56 patients found to have venous malformations of the knee, 6 patients (0 to 13 y, 4 females) were initially misdiagnosed as juvenile idiopathic arthritis and managed as such. Five of the 6 patients received nonsteroidal anti-inflammatory drugs. Of these 5, corticosteroids were also administered in 2 patients, and 1 also received methotrexate. One patient was treated conservatively.

CONCLUSIONS

Venous malformation of the knee can present as a clinical mimicker of juvenile idiopathic arthritis. Familiarity with the clinical presentation and imaging findings of these 2 disorders should minimize misdiagnosis of knee venous malformation as juvenile idiopathic arthritis and thus avoid inappropriate or delayed therapy.

LEVELS OF EVIDENCE

Types of Studies: Diagnostic Studies-Investigating a Diagnostic Test, Level III.

Differences in MRI findings between subgroups of recent-onset childhood arthritis

BACKGROUND

MRI is sensitive for joint inflammation, but its ability to separate subgroups of arthritis in children has been questioned. Infectious arthritis (IA), postinfectious arthritis (PA), transient arthritis (TA) and juvenile idiopathic arthritis (JIA) are subgroups that may need early, different treatment.

OBJECTIVE

To determine whether MRI findings differ in IA, PA/TA and JIA in recent-onset childhood arthritis.

MATERIALS AND METHODS

Fifty-nine children from a prospective study of incidence of arthritis (n = 216) were, based on clinical and biochemical criteria, examined by MRI. Joint fluid, synovium, bone marrow, soft tissue and cartilage were scored retrospectively and analysed by Pearson chi-square test and logistic regression analysis.

RESULTS

Fifty-nine children had MRI of one station. IA was suggested by bone marrow oedema (OR 7.46, P = 0.011) and absence of T1-weighted and T2-weighted low signal intensity synovial tissue (OR 0.06, P = 0.015). Furthermore, soft-tissue oedema and reduced contrast enhancement in the epiphyses were more frequent in children with IA. JIA correlated positively with low signal intensity synovial tissue (OR 13.30, P < 0.001) and negatively with soft-tissue oedema (OR 0.20, P = 0.018). No significant positive determinants were found for PA/TA, but bone marrow oedema, soft-tissue oedema, irregular thickened synovium and low signal intensity synovial tissue was less frequent than in IA/JIA.

CONCLUSION

In children with high clinical suspicion of recent onset arthritis, there was a significant difference in the distribution of specific MRI features among the diagnostic groups.

Juvenile idiopathic arthritis of peripheral joints: quality of reporting of diagnostic accuracy of conventional MRI

RATIONALE AND OBJECTIVES

The aim of this study was to systematically review the quality of papers on the clinimetric properties of magnetic resonance imaging for the diagnosis of juvenile idiopathic arthritis in peripheral joints.

MATERIALS AND METHODS

A review of Medline, EMBASE, the Database of Abstracts of Reviews of Effects, and the Cochrane Library was performed by using a systematic search strategy. Two independent reviewers evaluated selected articles by using Standards for Reporting of Diagnostic Accuracy (STARD) and Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tools. Items were reported independently for STARD and QUADAS.

RESULTS

Eighteen studies (validity, n = 18; reliability, n = 3; responsiveness, n = 3) were included. Their overall quality of reporting of methods was fair. Methodological problems with the STARD system included a lack of reporting of exclusion criteria (n = 14), partial or no information on operators' expertise (n = 14) or blinding (n = 18), and deficient information on study time frames (n = 12), treatments (n = 10), or indeterminate results (n = 18). The distribution of QUADAS scores was heterogeneous, with overall scores ranging between 3.5 (poor) and 16.5 (excellent) (maximum score, 17.5).

CONCLUSIONS

The quality of reporting of methods in studies on the magnetic resonance imaging assessment of juvenile idiopathic arthritis is heterogeneous and fair overall. Further methodological refinement of research design should be sought in future studies to provide stronger evidence for the value of novel techniques in clinical settings.

MRI in juvenile idiopathic arthritis and juvenile dermatomyositis

The use of MRI in the assessment of the musculoskeletal system in children has important differences from its use in adults. Growth in children has significant impact on the epiphysis and growth plate, which are important structures in the growing child, and there are radiological features that differ from those in adults: disease may alter structures during a period of growth; the pathologies themselves are a distinct group of diseases at variance with adult arthritis and myositis, with a different spectrum of differential diagnoses; and many technical issues are different when imaging a child. These are important considerations in choosing the appropriate imaging. MRI is a powerful and valuable imaging technique in pediatric musculoskeletal pathologies, with considerable potential for future developments to enhance its role in diagnosis, management, and therapeutic intervention for these children.

MR imaging of synovial disorders of the knee: an update

Synovial disorders often affect the knee joint and are a common cause of morbidity. Before MR imaging, radiologists were limited in their ability to provide information about the presence or absence of synovial disease. With the advent of MR imaging, useful information can now be provided to referring clinicians, often at a time when the initiation of therapy may mitigate significantly the long-term sequelae of synovial disorders. MR imaging, owing to its superior soft-tissue contrast, is the imaging modality of choice for demonstrating and quantifying pathologic changes of the synovium. MR imaging provides invaluable information to the clinician regarding the need to either initiate or modify therapy in those patients suffering from diseases of, or affecting, the synovium.

MR Imaging of Synovial Disorders of the Knee: An Update

Synovial disorders often affect the knee joint and are a common cause of morbidity. Before MR imaging, radiologists were limited in their ability to provide information about the presence or absence of synovial disease. With the advent of MR imaging, useful information can now be provided to referring clinicians, often at a time when the initiation of therapy may mitigate significantly the long-term sequelae of synovial disorders. MR imaging, owing to its superior soft-tissue contrast, is the imaging modality of choice for demonstrating and quantifying pathologic changes of the synovium. MR imaging provides invaluable information to the clinician regarding the need to either initiate or modify therapy in those patients suffering from diseases of, or affecting, the synovium.

Imaging of juvenile idiopathic arthritis

Over the past decade there have been considerable changes in the classification and imaging of juvenile idiopathic arthritis (JIA). Radiology now has a considerable role in the management of JIA, the differential diagnosis, monitoring disease progression and detecting complications. The different imaging modalities available, their role and limitations are discussed in this article and the various disease features that the radiologist should be aware of are described. An approach to the imaging of the child with joint disease and in the monitoring of disease complications are also discussed.

Juvenile rheumatoid arthritis manifesting in only limping due to flexion contraction of the knee

Juvenile rheumatoid arthritis (JRA) is a relatively uncommon condition. The damage to the cartilaginous tissue is often irreversible and responsible for much of the morbidity. Timely diagnosis and appropriate aggressive treatment of patients improve quality of life and outcome. A reported case of JRA is presented in which limping associated with flexion contraction of the knee developed without any systemic symptoms. Magnetic resonance imaging and arthroscopic examination were helpful with early diagnosis. Aspirin was effective. There have been no recurrence to date.

Advances in paediatric rheumatology: beyond NSAIDs and joint replacement

Over the previous three decades there have been a number of dramatic changes in our understanding of both the pathogenesis and epidemiology of the rheumatic diseases of childhood. Improvements in the classification of paediatric-onset arthritides and international collaboration in terms of multicentre research have led to the development of new therapeutic agents and better methods of outcome assessment for these chronic and often disabling conditions. Fortunately for children with paediatric rheumatic diseases treatment regimes are now available that provide excellent disease control for many and remission induction for some. Challenges include clearer definition of the genetics and pathogenesis of the diseases, delineation of reliable biological markers for diagnosis and monitoring of disease activity. The future should also herald early identification of those with a poorer prognosis, together with the design of more powerful, safer and cheaper remission-inducing agents, given to the right patients at the right time.