Imaging of juvenile idiopathic arthritis: a multimodality approach

The role of radiography in diagnosing, monitoring and prognosing juvenile idiopathic arthritis

The current role of conventional radiography in the diagnosis, monitoring and prognosis of juvenile idiopathic arthritis (JIA) is reviewed, as its role has changed with the increasing use of ultrasound and magnetic resonance imaging, as well as with the introduction of biological drugs. Conventional radiography does not play an important role in the diagnosis of JIA, as this is based on history, clinical examination and laboratory findings. The main role of conventional radiography is in the detection and monitoring of growth disorders and chronic structural and morphological changes of the affected joints and bones, in addition to helping with the differential diagnosis of conditions that mimic JIA. Radiographic changes of the joints depend on the age of the child, the type and duration of arthritis and the specific joints affected. There are no standard protocols for arthritis monitoring and most indications for imaging are based on individual case-by-case decisions. The development of degenerative joint changes is considered a poor predictive factor, but there are no clear studies that more precisely define the predictive value of radiographic changes. Conventional radiography remains an important imaging modality in narrowing the differential diagnosis and in evaluating growth disorders and the developing destructive joint changes.

Imaging findings of juvenile idiopathic arthritis and autoinflammatory diseases in children

Juvenile idiopathic arthritis (JIA) is a collective term for pediatric inflammatory arthritis of unknown etiology, which presents diverse clinical and imaging findings. The pathogenesis is complex; however, most cases stem from an autoimmune mechanism. Herein we provide a short review of imaging findings of JIA. Imaging assessment begins with plain radiography demonstrating joint swelling, periarticular osteopenia, and juxtaarticular bone erosion. Bone erosion occurs later in JIA. Instead, aberrant epimetaphyseal growth often gives the first clue to the diagnosis. US and MRI can demonstrate the details of the synovium, cartilage, and subchondral bone. JIA is subdivided into oligoarthritis, polyarthritis (rheumatoid factor-negative and positive), psoriatic arthritis, enthesitis-related arthritis, and systemic JIA. Awareness of the different clinical characteristics, pathogenic background, and prognosis of each subtype facilitates a more advanced, imaging-based diagnosis. Unlike the other types, systemic JIA is an autoinflammatory disease accompanied by inflammatory cytokinemia and systemic symptoms stemming from aberrant activation of the innate immunity. Other autoinflammatory diseases, both monogenic (e.g., NOMID/CINCA) and multifactorial (e.g., CRMO), are also discussed.

Ultrasound and MRI of the foot in children and adolescents newly diagnosed with juvenile idiopathic arthritis

Aim

To evaluate the spectrum of inflammatory features in foot joints which may be detected on routinely performed ultrasound (US) and magnetic resonance imaging (MRI) in children newly diagnosed with juvenile idiopathic arthritis (JIA).

Material and methods

Two groups of children hospitalized in a reference center for rheumatology, newly diagnosed with JIA and suspected of foot involvement in the course of JIA were included in this retrospective study. In the first group of 47 patients aged 1-18 years, the imaging was restricted to US. The second group of 22 patients aged 5-18 years underwent only non-contrast MRI of the foot.

Results

The most frequent pathologies seen on US included effusion and synovial thickening in the first metatarsophalangeal joint (MTP1), followed by the tibiotalar joint. Synovial hyperemia on color Doppler US images was present most frequently in the Chopart and midtarsal joints (64%; 7/11 cases), followed by the tibiotalar joint (45%; 5/11), and MTP2-5 joint synovitis (40%; 4/10). Grade 3 hyperemia was present only in four cases; grades 1 and 2 were detected in the majority of cases. On MRI, bone marrow edema was the most frequent pathology, found mostly in the calcaneus (45%; 10/22 cases), while alterations of the forefoot were rare. No cases of bursitis, enthesitis, cysts, erosions or ankylosis were diagnosed in either of the analyzed groups.

Conclusions

Routine US of the foot is recommended for early detection of its involvement in JIA in daily clinical practice. Although MRI can identify features of various JIA stages, it is particularly useful for the detection of bone marrow alterations.

C1-C2 subluxation in enthesitis-related arthritis: two case reports and literature review of ten cases

BACKGROUND

C1-C2 subluxation is a rare complication of enthesitis-related arthritis (ERA). If left untreated, it may lead to functional impairment or cervical spinal cord compression. This study aims to highlight key points regarding the management of C1-C2 subluxation in ERA.

CASE PRESENTATION

We present two cases of C1-C2 subluxation: an 8-year-old boy with ERA and 16-year-old boy with ERA with bilateral sacroiliitis. Ten cases of ERA in the literature were reviewed. The diagnosis of C1-C2 subluxation is mostly based on radiographs and cervical spine computed tomography. All patients were treated with non-steroidal anti-inflammatory drugs. Six ERA patients were treated surgically for cervical fusion. Most ERA patients with sacroiliitis had cervical collar protection. Neurologic abnormalities after treatment were not reported. Despite the use of cervical collar, cervical fusion and persisting ankylosis were found in two ERA patients with sacroiliitis without surgical treatment.

CONCLUSIONS

Cervical spine protection and ruling out spinal cord compression should be prioritized, in addition to controlling the underlying inflammation in ERA. Cervical halter traction may be applied after severe cervical inflammation is excluded. To reduce the risk of complications, early recognition and appropriate treatments of C1-C2 subluxation in ERA are essential.

Evaluation of paediatric hip pain

Hip pain in a child can pose a diagnostic conundrum. In most cases, the cause of a painful hip is often attributed to trauma, but a number of these cases will be atraumatic. The main entities to consider are inflammatory, infective and neoplastic causes. Pathologies such as avascular necrosis and slipped upper femoral epiphysis can also present in a similar manner. A detailed history and clinical examination are crucial in narrowing down the differential diagnosis. In addition, understanding the most appropriate imaging modalities and the characteristic radiological findings is key in ensuring timely treatment and management. This article reviews the various disease processes in children who present with hip pain and outlines the most appropriate assessment and imaging modalities that will aid diagnosis.

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.

Foot and Ankle Conventional Radiography in Juvenile Idiopathic Arthritis: Does It Still Matter?

Objectives:

The aim of this study was to evaluate the residual value of Conventional Radiography in children with arthralgia clinically suspected of Juvenile Idiopathic Arthritis (JIA).

Materials and Methods:

Three hundred seventy-two patients aged 1–18 years suspected of JIA were retrospectively reviewed. All patients had foot and ankle plain films performed in standard two projections: ankle in antero-posterior and lateral, and foot in antero-posterior and oblique. The cohort was divided into two groups: patients with confirmed JIA and non-JIA control group of children with foot and ankle arthralgia without diagnosis of inflammatory connective tissue disease. Radiographic findings in both groups were compared.

Results:

In 40% of JIA and 70% of non-JIA patients radiographs were normal. All radiographic findings were significantly more common in JIA than in non-JIA group (p = 0.000). Soft tissue swelling was the most frequent abnormality found in JIA patients (31, 51%) and only in 2.41% of non-JIA patients (p = 0.000). Osteoporosis and joint space narrowing were also significantly more common in JIA group (p = 0.000). The majority of imaging findings in non-JIA group were non-inflammatory abnormalities.

Conclusion:

Conventional radiography is an important tool in differential diagnosis of arthralgia of unknown etiology, as soft tissue swelling, osteoporosis and joint space narrowing are significantly more common in JIA patients as compared with patients without the diagnosis of inflammatory connective tissue disease. However, in case of high clinical suspicion of JIA and normal radiography, we recommend subsequent ultrasound (US) and/or MRI to allow early treatment.

Improving protocols for whole-body magnetic resonance imaging: oncological and inflammatory applications

Whole-body MRI is increasingly used in the evaluation of a range of oncological and non-oncological diseases in infants, children and adolescents. Technical innovation in MRI scanners, coils and sequences have enabled whole-body MRI to be performed more rapidly, offering large field-of-view imaging suitable for multifocal and multisystem disease processes in a clinically useful timeframe. Together with a lack of ionizing radiation, this makes whole-body MRI especially attractive in the pediatric population. Indications include lesion detection in cancer predisposition syndrome surveillance and in the workup of children with known malignancies, and diagnosis and monitoring of a host of infectious and non-infectious inflammatory conditions. Choosing which patients are most likely to benefit from this technology is crucial, but so is adjusting protocols to the patient and disease to optimize lesion detection. The focus of this review is on protocols and the elements impacting image acquisition in pediatric whole-body MRI. We consider the practical aspects, from scanner and coil selection to patient positioning, single-center generic and indication-specific protocols with technical parameters, motion reduction strategies and post-processing. When optimized, collectively these lead to better standardization of whole-body MRI, and when married to systematic analysis and interpretation, they can improve diagnostic accuracy.

Monogenic disorders as mimics of juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis is the most common chronic rheumatic disease of childhood. The term JIA encompasses a heterogenous group of diseases. The variability in phenotype of patients affected by the disease means it is not uncommon for mimics of JIA to be misdiagnosed.

CASE PRESENTATION

We present four cases who were treated in single tertiary rheumatology centre for JIA who were subsequently diagnosed with a rare monogenic disease. All four patients shared the unifying features of presenting in early childhood and subsequently suffered with refractory disease, not amenable to usual standards of treatment. Multicentric Carpotarsal Osteolysis Syndrome and Camptodactyly-arthropathy-coxa vara-pericarditis syndrome are non-inflammatory conditions and patients typically present with arthropathy, normal inflammatory markers and atypical radiological features. Blau syndrome is an autosomal dominant condition and patients will typically have symmetrical joint involvement with a strong family history of arthritis, signifying the genetic aetiology.

CONCLUSIONS

We share our learning from these cases to add to the growing portfolio of JIA mimics and to highlight when to consider an alternative diagnosis. In cases of refractory disease and diagnostic uncertainty further imaging and genetic testing can play a crucial role in establishing the aetiology. In all of these cases the correct diagnosis was made due to careful, longitudinal clinical phenotyping and a close working relationship between rheumatology, radiology and clinical genetics; highlighting the importance of the multidisciplinary team in managing complex patients.

An Expert-Supervised Registration Method for Multiparameter Description of the Knee Joint Using Serial Imaging

As knee osteoarthritis is a disease of the entire joint, our pathophysiological understanding could be improved by the characterization of the relationships among the knee components. Diverse quantitative parameters can be characterized using magnetic resonance imaging (MRI) and computed tomography (CT). However, a lack of methods for the coordinated measurement of multiple parameters hinders global analyses. This study aimed to design an expert-supervised registration method to facilitate multiparameter description using complementary image sets obtained by serial imaging. The method is based on three-dimensional tissue models positioned in the image sets of interest using manually placed attraction points. Two datasets, with 10 knees CT-scanned twice and 10 knees imaged by CT and MRI were used to assess the method when registering the distal femur and proximal tibia. The median interoperator registration errors, quantified using the mean absolute distance and Dice index, were ≤0.45 mm and ≥0.96 unit, respectively. These values differed by less than 0.1 mm and 0.005 units compared to the errors obtained with gold standard methods. In conclusion, an expert-supervised registration method was introduced. Its capacity to register the distal femur and proximal tibia supports further developments for multiparameter description of healthy and osteoarthritic knee joints, among other applications.

Late-infantile GM1 gangliosidosis: A case report

RATIONALE

Monosialotetrahexosylganglioside (GM1) gangliosidosis is a rare lysosomal storage disorder caused by the deficiency of ß-galactosidase. Because clinical symptoms of GM1 gangliosidosis overlap with other neurodevelopmental disorders, the diagnosis of this disease is not easy, specifically in late infantile GM1 gangliosidosis. This report described a case of late-infantile GM1 gangliosidosis mistaken for juvenile idiopathic arthritis.

PATIENT CONCERNS

A 16-year-old girl was referred to our hospital due to persistent multiple joint deformities and mental retardation, which could not be explained by juvenile idiopathic arthritis.

DIAGNOSIS

We made a diagnosis of late infantile GM1 gangliosidosis through enzyme assays and genetic testing after a skeletal survey.

INTERVENTIONS

The patient underwent cervical domeplasty and laminectomy for cord compression and received rehabilitation treatment.

OUTCOMES

The patient is receiving multidisciplinary care at a tertiary center for variable skeletal disease and conditions associated with GM1 gangliosidosis.

LESSONS

Late infantile GM1 gangliosidosis should be considered in the differential diagnosis of progressive neurologic decline and skeletal dysostosis.

Recommendations for Management of Childhood Psoriasis

Childhood psoriasis is recognized as a potential multisystem disorder and hence it is imperative to optimize disease management to arrest progression, minimize psychological burden and evolution of metabolic syndrome. Clinical practice recommendations are necessary to assist practitioners in appropriate decision making based on available evidence. Owing to the lack of Indian recommendations on childhood psoriasis, the SIG Pediatric Dermatology under IADVL Academy undertook an evidence-based approach based on published literature on the topic, between January 2000 and July 2020 to frame the recommendations.

Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part I: Active lesions

Magnetic resonance imaging (MRI) is an increasingly important tool for identifying involvement of the sacroiliac joints (SIJ) in juvenile idiopathic arthritis (JIA). The key feature for diagnosing active sacroiliitis is bone marrow edema (BME), but other features of active arthritis such as joint space inflammation, inflammation in an erosion cavity, capsulitis and enthesitis can be seen as well. Structural changes may also be seen. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the disease course, choice of therapeutics and evaluating treatment response. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of SIJ inflammation. This atlas demonstrates fundamental MRI disease features of active inflammation in a format that can serve as a reference for assessing SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 2, Structural Lesions.

A possible case of juvenile idiopathic arthritis from Renaissance Lucca (Tuscany, central Italy)

OBJECTIVE

The skeletal remains of a young individual (Guinigi US 1278) are described and a differential diagnosis is performed to determine the potential etiology of bone alterations.

MATERIALS

Archaeological excavations conducted at the private funerary chapel of the upper class members of the Guinigi family (14th-17th centuries AD) of Lucca (Tuscany, central Italy) brought to light the fragmented human skeletal remains of a young individual (Guinigi US 1278) with pathological osseous modifications.

METHODS

Morphological and radiological analyses were followed by differential diagnosis.

RESULTS

Guinigi US 1278 was a non-adult aged 16-20 years, who exhibited florid skeletal alterations in the form of vertebral fusion and extensive subchondral bone changes of the small and large joints of the appendicular skeleton. The severity of the resorptive process in the peripheral joints, as well as vertebral fusion, indicates a long-standing inflammatory process.

CONCLUSIONS

The features and the distribution of the skeletal lesions of Guinigi US 1278 are highly consistent with a form of juvenile idiopathic arthritis (JIA), leading to irreversible phenomena such as subchondral erosive lesions and axial ankylosis, with impairment of the gait and neck movements.

SIGNIFICANCE

While abundant clinical literature on JIA is available, paleopathological studies are scarce. The possible case of JIA from Lucca provides a direct opportunity to examine the chronic course of rheumatic disease in young individuals in the absence of appropriate medical therapies in the antiquity.

SUGGESTIONS FOR FURTHER RESEARCH

Future molecular analyses might be able to identify specific alleles of the HLA region responsible for JIA subtypes.

MR Imaging of Rheumatic Diseases Affecting the Pediatric Population

This article reviews the application of magnetic resonance imaging (MRI) to pediatric rheumatic diseases. MRI can detect early manifestations of arthritis, evaluate the extent of disease, and monitor disease activity and response to treatment.Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disorder, representing a diverse group of related diseases that share a definition of joint inflammation of unknown origin with onset before 16 years of age and lasting > 6 weeks. JIA may lead to significant functional impairment and is increasingly imaged with MRI to assess for active inflammation as a target for therapy. This is particularly true for juvenile spondyloarthritis that includes multiple subgroups of JIA and primarily involves the spine and sacroiliac joints.Other less common pediatric rheumatic diseases considered here are chronic recurrent multifocal osteomyelitis and collagen vascular diseases including polymyositis, dermatomyositis, scleroderma, and juvenile systemic lupus erythematosus.

Conventional Radiography and Ultrasound Imaging of Rheumatic Diseases Affecting the Pediatric Population

Juvenile idiopathic arthritis is the most frequent rheumatic disease in the pediatric population, followed by systemic lupus erythematosus, juvenile scleroderma syndromes, juvenile dermatomyositis, chronic recurrent multifocal osteomyelitis, and juvenile vasculopathies. The imaging approach to inflammatory connective tissue diseases in childhood has not changed dramatically over the last decade, with radiographs still the leading method for bony pathology assessment, disease monitoring, and evaluation of growth disturbances. Ultrasonography is commonly used for early detection of alterations within the intra- and periarticular soft tissues, assessing their advancement and also disease monitoring. It offers several advantages in young patients including nonionizing radiation exposure, short examination time, and high resolution, allowing a detailed evaluation of the musculoskeletal system for the features of arthritis, tenosynovitis, enthesitis, bursitis, myositis, as well as pathologies of the skin, subdermis, vessels, and fasciae. In this pictorial essay we discuss radiographic and ultrasound inflammatory features of autoimmune pediatric inflammatory arthropathies: juvenile idiopathic arthritis, lupus erythematosus, juvenile scleroderma, juvenile dermatomyositis and polymyositis.

The Pediatric Spine

The spine, a frequently investigated site in children, has a complex development in relation to both nervous and bone/cartilaginous structures and shows several particular features in children compared with adults. We report the main normal variants and pathologies of the pediatric spine, from the prenatal period to adolescence, focusing on a multimodality imaging approach.

Toward Developing a Semiquantitative Whole Body-MRI Scoring for Juvenile Idiopathic Arthritis: Critical Appraisal of the State of the Art, Challenges, and Opportunities

With powerful new therapies available for management of juvenile idiopathic arthritis (JIA), early diagnosis leading to appropriate treatment may prevent long-term structural joint damage. Although magnetic resonance imaging (MRI) is typically used to assess individual body parts, indications for whole body (WB) MRI are increasing. Its utility as a diagnostic and monitoring tool has already been widely investigated in adult rheumatology patients, but less so in pediatric rheumatologic patients. This paper is a comprehensive review of scoring systems and a proposal for the conceptual development of a WB-MRI scoring system for the evaluation of JIA. In this review we identify, summarize, and critically appraise the available literature on the use of WB-MRI in inflammatory arthritis, addressing relevant considerations on components of a classification system that can lead to the development of a future pediatric WB-MRI scoring system for use in children with JIA. We also discuss advantages and challenges of developing such a WB-MRI scoring system for assessment of JIA and outline next steps toward the conceptual development of this scoring system.

Imaging assessment of children presenting with suspected or known juvenile idiopathic arthritis: ESSR-ESPR points to consider

Juvenile idiopathic arthritis (JIA) is the most common paediatric rheumatic disease. It represents a group of heterogenous inflammatory disorders with unknown origin and is a diagnosis of exclusion in which imaging plays an important role. JIA is defined as arthritis of one or more joints that begins before the age of 16 years, persists for more than 6 weeks and is of unknown aetiology and pathophysiology. The clinical goal is early suppression of inflammation to prevent irreversible joint damage which has shifted the emphasis from detecting established joint damage to proactively detecting inflammatory change. This drives the need for imaging techniques that are more sensitive than conventional radiography in the evaluation of inflammatory processes as well as early osteochondral change. Physical examination has limited reliability, even if performed by an experienced clinician, emphasising the importance of imaging to aid in clinical decision-making. On behalf of the European Society of Musculoskeletal Radiology (ESSR) arthritis subcommittee and the European Society of Paediatric Radiology (ESPR) musculoskeletal imaging taskforce, based on literature review and/or expert opinion, we discuss paediatric-specific imaging characteristics of the most commonly involved, in literature best documented and clinically important joints in JIA, namely the temporomandibular joints (TMJs), spine, sacroiliac (SI) joints, wrists, hips and knees, followed by a clinically applicable point to consider for each joint. We will also touch upon controversies in the current literature that remain to be resolved with ongoing research. KEY POINTS: • Juvenile idiopathic arthritis (JIA) is the most common chronic paediatric rheumatic disease and, in JIA imaging, is increasingly important to aid in clinical decision-making. • Conventional radiographs have a lower sensitivity and specificity for detection of disease activity and early destructive change, as compared to MRI or ultrasound. Nonetheless, radiography remains important, particularly in narrowing the differential diagnosis and evaluating growth disturbances. • Mainly in peripheral joints, ultrasound can be helpful for assessment of inflammation and guiding joint injections. In JIA, MRI is the most validated technique. MRI should be considered as the modality of choice to assess the axial skeleton or where the clinical presentation overlaps with JIA.

Surgical outcomes of open hip reduction with synovectomy for developmental dysplasia of the hip patient with Juvenile idiopathic arthritis: A case report

INTRODUCTION

Developmental dysplasia of the hip (DDH) is a common hip disorder and its association with other musculoskeletal, genetic, and neurological diseases were well described in the literature. Juvenile idiopathic arthritis (JIA) is a rare rheumatological condition, and its presence in a Developmental dysplasia of the hip (DDH) child makes this a very challenging case.

PRESENTATION OF THE CASE

This case report is describing the presentation of 9 months old girl to orthopedic service referred from the pediatric rheumatology clinic after diagnosing her and starting the treatment for Juvenile idiopathic arthritis (JIA). Bilateral neglected Developmental dysplasia of the hip (DDH) - International Hip Dysplasia Institute (IHDI) type 4- was detected during her clinical and radiological assessment, necessitating surgical management after controlling her Juvenile idiopathic arthritis (JIA). The surgical procedure and its clinical and radiological outcomes more than four years after her surgical treatment are described in detail in this report as well.

DISCUSSION

The management of Developmental dysplasia of the hip (DDH) associated with Juvenile idiopathic arthritis (JIA) has no established guidelines in literature. Here, we share our experience in managing such rare cases. We believe that medical control of Juvenile idiopathic arthritis (JIA) before proceeding for open reduction of Developmental dysplasia of the hip (DDH) is the key to successful results.

CONCLUSION

The reported case is uniquely having both Developmental dysplasia of the hip (DDH) and Juvenile idiopathic arthritis (JIA) treated with open reduction, pelvic osteotomy, and femoral shortening resulting in outstanding clinical and radiological outcomes.

Autoinflammatory diseases in childhood, part 2: polygenic syndromes

Autoinflammatory diseases are a family of disorders characterized by aberrant stimulation of inflammatory pathways without involvement of antigen-directed autoimmunity. They can be further divided in monogenic and polygenic types. Those without an identified genetic mutation are known as polygenic and include systemic-onset juvenile idiopathic arthritis, idiopathic recurrent acute pericarditis, Behçet syndrome, chronic recurrent multifocal osteomyelitis and inflammatory bowel disease among others. Autoinflammatory diseases are characterized by recurrent flares or persistent systemic inflammation and fever, as well as lymphadenopathy and cutaneous, abdominal, thoracic and articular symptoms. Although these syndromes can mimic infections clinically, the inflammatory lesions in autoinflammatory disorders are aseptic. However, because of their infrequency, varied and nonspecific presentation, and the new genetic identification, diagnosis is usually delayed. In this article, which is Part 2 of a two-part series, the authors review the main polygenic autoinflammatory diseases that can be seen in childhood, with special emphasis wherever applicable on imaging features that may help establish the correct diagnosis. However, the major role of imaging is to delineate organ involvement and disease extent.

Tumefactive synovial thickening mimicking synovial chondromatosis in the setting of oligoarticular juvenile idiopathic arthritis in a toddler

Juvenile idiopathic arthritis (JIA) is the most common cause of arthritis in children. It is characterized by inflammatory cell infiltration of synovial membranes leading to synovitis and synovial membrane thickening. Synovial chondromatosis is rare sequela of synovitis in which foci of cartilage develop within the synovial membrane of a joint capsule. We report a case of a 35-month old boy who developed tumefactive synovial hypertrophy and hyperplasia that mimicked synovial chondromatosis on MRI. The reactive synovium was arthroscopically excised and the patient's arthritis improved. Tumefactive synovial hypertrophy and hyperplasia mimicking synovial chondromatosis on MRI in the setting of JIA, has not been reported in this young of a patient in the literature to date. A discussion on imaging in oligoarticular JIA and synovial chondromatosis is presented herein.

Spinal Manifestations of Systemic Disease

The spine is frequently involved in systemic diseases, including those with neuropathic, infectious, inflammatory, rheumatologic, metabolic, and neoplastic etiologies. This article provides an overview of systemic disorders that may affect the spine, which can be subdivided into disorders predominantly involving the musculoskeletal system (including bones, joints, disks, muscles, and tendons) versus those predominantly involving the nervous system. By identifying the predominant pattern of spine involvement, a succinct, appropriate differential diagnosis can be generated. The importance of reviewing the medical record, as well as prior medical imaging (including nonspine imaging), which may confer greater specificity to the differential diagnosis, is stressed.

Inter- and intra-observer reliability of contrast-enhanced magnetic resonance imaging parameters in children with suspected juvenile idiopathic arthritis of the hip

BACKGROUND

Previous work at our institution demonstrated discrepancies between radiologists in interpretation of contrast-enhanced magnetic resonance imaging (MRI) in suspected hip arthritis.

OBJECTIVE

To assess inter- and intra-observer reliability of selected MRI parameters (effusion, marrow oedema and synovial thickness and enhancement) used in the diagnosis of juvenile idiopathic arthritis.

MATERIALS AND METHODS

A retrospective cohort study was conducted of patients with confirmed or suspected juvenile idiopathic arthritis who underwent hip contrast-enhanced MRI between January 2011 and September 2014. Three pediatric musculoskeletal radiologists independently assessed all scans for effusion, marrow oedema, measurement of synovial thickness, synovial enhancement and subjective assessment of synovium. Categorical variables were analysed using the Cohen κ, and measurement using Bland-Altman plots.

RESULTS

Eighty patients were included. Interobserver reliability was moderate for effusion (κ=0.5-0.7), marrow oedema (κ=0.6), subjective synovial assessment (κ=0.4-0.5) and synovial enhancement (κ=0.1-0.5). Intra-observer reliability was highest for marrow oedema (κ=0.6-0.8) and lowest for effusion (κ=0.4-0.7). Intra-observer reliability for synovial enhancement (κ= -0.7-0.8) and subjective synovial assessment (κ=0.4-1.0) ranged from poor to excellent. For synovial thickness, intra- and interobserver Bland-Altman plots were well clustered around the mean suggesting good agreement.

CONCLUSION

There were large differences across variables and only moderate agreement between observers. The most reliable parameters were presence of joint effusion and bone marrow oedema and subjective assessment of synovium.

Imaging of the limping child

Limping is a challenging symptom in the pediatric patient as the diagnosis can range from traumatic, malformative, infectious/inflammatory and neoplastic diseases. In this paper, we propose a schematic imaging algorithm to the limping child in three different age groups (Toddler: 1-3years, child: 4-10 years; adolescent: 11-16 years) based on presence of signs of infection, any specific localization of pain, and history of trauma. In this setting, the most common imaging pitfalls are also summarised. Finally, a literature review of the main differential causes of limping in the pediatric patient is reported.

Reliability of ultrasonography to detect inflammatory lesions and structural damage in juvenile idiopathic arthritis

BACKGROUND

Musculoskeletal Ultrasonography (MSUS) is an important tool for the clinical assessment in Juvenile Idiopathic Arthritis (JIA). The objective of this study was to evaluate the reliability of MSUS to detect elementary lesions: synovitis, tenosynovitis, cartilage damage and bone erosions in the wrist and metacarpal (MCP) joints of patients with JIA.

METHODS

Thirty children in various subgroups of JIA according to ILAR criteria, were included in this cross-sectional study. Clinical data including painful, swollen and limited joints were recorded. Five rheumatologist ultrasonographers, blinded to the clinical evaluation, evaluated the presence of elementary lesions in the wrist and MCP 2 and 3 joints bilaterally. The synovitis was graded in B-Mode and Power Doppler (PD). In addition to descriptive statistics intra- and inter-observer reliability was calculated using Cohen's kappa according to Landis and Koch.

RESULTS

US detected more synovitis than the clinical examination (62% vs 28%, 30% vs 23% and 22% vs 17% in the wrist, second and third MCP joints respectively). The intra-observer concordance for synovitis in all joints was excellent in B-Mode (k 0.84 .63-1.0 p = 0.001), except for MCP 2, where it was good (0.61, IC 95% .34-89, p = 0.001). For both modalities (PD, B-Mode) tenosynovitis, cartilage damage and bone erosions it was also excellent. Regarding synovitis grading the concordance was excellent for all grades (0.83-1.0, IC 95% 0.51.1.0, p = 0.001), except for grade 1 where it was good (0.61, IC 95% 0.43-.83, p = 0.001). Reliability inter-observer for grayscale synovitis (0.67-0.95, IC 95% 0.67-1.0, p = 0.001), tenosynovitis grayscale (0.89, IC 95% 0.78-0.99, p.001), damage cartilage (0.89, IC 95% 0.78-0.99, p = 0.001), PD (0.66, IC 95% 0.39-1.0, p = 0.001). The concordance for grading synovitis was excellent, but for grayscale grade 1 and 2 (.66, IC 95% .53-.74, p = 0.007) and PD grade 1 and 2 (0.63, IC 95% .58-.91, p = 004) was good.

CONCLUSIONS

The intra- and inter-observer reliability of MSUS for inflammatory and structural lesions is good to excellent for the wrist and MCP in patients with JIA.

Imaging of the hip in juvenile idiopathic arthritis

Hip involvement is common and estimated to occur in approximately 35-63% of children with juvenile idiopathic arthritis (JIA). It is more prevalent in the aggressive systemic subtypes, with irreversible changes occurring as early as within 5 years of diagnosis. Whilst clinical parameters and joint examination can be useful for assessing disease severity, subclinical disease is known to exist and delayed treatment may herald a lifetime of disability and pain. Early recognition of JIA changes is therefore crucial in determining treatment options. Validated scoring systems in the radiologic assessment of the hip for clinical drug trials may inform treatment outcomes, although robust tools for analysis are still lacking. This review article details the modalities utilised for imaging the hip in children with JIA with particular efforts focused upon reliability and validity in their assessment of joint disease. We conclude with a short literature review on the potential future techniques being developed for hip joint imaging in JIA.

Current status of wrist imaging in juvenile idiopathic arthritis

Wrist involvement occurs in about one-quarter of patients diagnosed with juvenile idiopathic arthritis (JIA), increasing to 40% 5 years after diagnosis. The imaging appearances, both for active inflammation and permanent change, differ from those seen in adult rheumatoid arthritis; therefore, a child-specific approach is crucial for correct assessment. In this review article, we provide an update on the current status for imaging wrist JIA, with a focus on evidence-based practice.

Magnetic resonance imaging of sacroiliitis in children: frequency of findings and interobserver reliability

BACKGROUND

Clinicians increasingly rely on imaging in juvenile idiopathic arthritis (JIA) to identify sacroiliitis and guide treatment. However, there is limited evidence about magnetic resonance imaging (MRI) for sacroiliitis in children, and interobserver reliability is variable.

OBJECTIVE

Identify the frequency of MRI findings in children with suspected sacroiliitis, calculate inter-reporter reliability and assess the value of diffusion-weighted imaging and contrast-enhanced sequences.

MATERIALS AND METHODS

We retrospectively reviewed 3 years of sacroiliac joint MRI records for suspected sacroiliitis in patients <21 years at a United Kingdom tertiary referral paediatric hospital. Five radiologists (panel of three radiologists and two independent radiologists) reviewed all MRI examinations using a pictorial checklist to identify oedema, effusions, diffusion-weighted signal abnormality, enhancement, erosions and sclerosis. The frequency of panel findings was reported. Interobserver agreement was calculated using the Cohen kappa coefficient.

RESULTS

An MRI diagnosis of sacroiliitis was made in 12 of 99 examinations (12%). The findings in all scans included oedema (9%), erosions (8%), diffusion-weighted signal abnormality (6%), abnormal enhancement (6%) and effusion (4%). All scans with abnormal contrast enhancement had other MRI features of sacroiliitis. Interobserver agreement was slight to moderate.

CONCLUSION

Oedema and erosions were the most common findings. Inter-reporter reliability was variable with at best moderate agreement for the presence of sacroiliitis and erosions. The use of contrast enhancement for diagnosing sacroiliitis in children with JIA may be questionable.

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.

Clinical applications of advanced magnetic resonance imaging techniques for arthritis evaluation

Magnetic resonance imaging (MRI) has allowed a comprehensive evaluation of articular disease, increasing the detection of early cartilage involvement, bone erosions, and edema in soft tissue and bone marrow compared to other imaging techniques. In the era of functional imaging, new advanced MRI sequences are being successfully applied for articular evaluation in cases of inflammatory, infectious, and degenerative arthropathies. Diffusion weighted imaging, new fat suppression techniques such as DIXON, dynamic contrast enhanced-MRI, and specific T2 mapping cartilage sequences allow a better understanding of the physiopathological processes that underlie these different arthropathies. They provide valuable quantitative information that aids in their differentiation and can be used as potential biomarkers of articular disease course and treatment response.

Ultrasound imaging of synovial inflammation in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common rheumatic entity of childhood. The hallmark feature of all subtypes is joint inflammation. Imaging is used to evaluate the extent and severity of inflammation, degree of joint damage and response to treatment, which in turn impacts patient management. Ultrasound has become a useful adjunct to clinical examination because it shows promise in evaluating clinical and subclinical inflammation (synovitis, enthesitis) as well as cartilage and bone erosive changes. However more collaborative research is needed to help define the normal appearance of the growing skeleton, clarify the significance of subclinical findings and develop useful definitions, imaging protocols and scoring systems of disease.

Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis: a promising imaging biomarker as an alternative to gadolinium-based contrast agents

Objectives

To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA).

Methods

Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman’s rank was used to analyse the correlation between DCE and DWI.

Results

Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 × 10^-3mm²/s in MRI-active and 1.25 × 10^-3mm²/s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 × 10^-3mm²/s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05).

Conclusions

Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI.

Key Points

• MRI can quantify: dynamic contrast-enhanced and diffusion-weighted MRI can quantify synovitis

• Both DWI and DCE can differentiate active from inactive JIA

• The DWI-derived apparent diffusion coefficient (ADC) is higher in active JIA

• DWI is non-invasive and thus safer and more patient-friendly

• DWI is a potentially powerful and non-invasive imaging biomarker for JIA

Clinical and MRI outcome of cervical spine lesions in children with juvenile idiopathic arthritis treated with anti-TNFα drugs early in disease course

BACKGROUNDS

The purpose of the study was to evaluate the clinical and magnetic resonance imaging (MRI) outcome of cervical spine arthritis in children with juvenile idiopathic arthritis (JIA), who received anti-TNFα early in the course of cervical spine arthritis.

METHODS

Medical charts and imaging of JIA patients with cervical spine involvement were reviewed in this retrospective study. Data, including age at disease onset, JIA type, disease activity, treatment and clinical outcome were collected. Initial and followup MRI examinations of cervical spine were performed according to the hospital protocol to evaluate the presence of inflammation and potential chronic/late changes.

RESULTS

Fifteen JIA patients with MRI proved cervical spine inflammation (11 girls, 4 boys, median age 6.3y) were included in the study: 9 had polyarthritis, 3 extended oligoarthritis, 2 persistent oligoarthritis and 1 juvenile psoriatic arthritis. All children were initially treated with high-dose steroids and methotrexate. In addition, 11 patients were treated with anti-TNFα drug within 3 months, and 3 patients within 7 months of cervical spine involvement confirmed by MRI. Mean observation time was 2.9y, mean duration of anti-TNFα treatment was 2.2y. Last MRI showed no active inflammation in 12/15 children, allowing to stop biological treatment in 3 patients, and in 3/15 significant reduction of inflammation. Mild chronic changes were found on MRI in 3 children.

CONCLUSIONS

Early treatment with anti-TNFα drugs resulted in significantly reduced inflammation or complete remission of cervical spine arthritis proved by MRI, and prevented the development of serious chronic/late changes. Repeated MRI examinations are suggested in the follow-up of JIA patients with cervical spine arthritis.

Joint Fluid, Bone Marrow Edemalike Changes, and Ganglion Cysts in the Pediatric Wrist: Features That May Mimic Pathologic Abnormalities-Follow-Up of a Healthy Cohort

OBJECTIVE

The presence of findings at wrist MRI that may mimic disease is a diagnostic problem. The purpose of this study is to examine the occurrence of bone marrow changes resembling edema, joint fluid, and ganglion cysts over time, in a cohort of healthy children.

MATERIALS AND METHODS

Seventy-four of 89 healthy children included in a study of normal MRI findings of the wrists were reexamined after a period of 4 years, using the same 1.5-T MRI technique-namely, a coronal T1-weighted and a T2-weighted fat-saturated sequence. A history of handedness, diseases, and sports activity was noted.

RESULTS

Bone marrow edema or edemalike changes were seen in 29 of 74 (39.2%) wrists in 2013 as compared with 35 of 72 (48.6%) wrists in 2009 (p = 0.153), all in different locations. Changes were found in central parts of the bone, on both sides of a joint, or near bony depressions. Fifty percent of all subjects had at least one fluid pocket greater than or equal to 2 mm. The location was unchanged in 47% of the joints. In 24% of the individuals, at least one ganglion cyst was seen. Six ganglion cysts present on the first scan were not seen on the follow-up scan, and 11 new ganglion cysts had appeared.

CONCLUSION

Awareness of normal MRI appearances of the growing skeleton is crucial when interpreting MRI of children, and such findings must not be interpreted as pathologic abnormalities.

Association of the apparent diffusion coefficient with maturity in adolescent sacroiliac joints

PURPOSE

To determine the extent to which apparent diffusion coefficient (ADC) values vary with skeletal maturity in adolescent joints.

MATERIALS AND METHODS

A retrospective study was performed with Institutional Review Board (IRB) approval. We used a picture archiving and communication system (PACS) search to identify and recruit all adolescents who had undergone 1.5T magnetic resonance imaging (MRI) of the sacroiliac joints (SIJs) between January 2010 and June 2015, and had no evidence of sacroiliitis and normal inflammatory markers. In all, 55 individuals were assessed. For each patient, coronal and sagittal images of the sacrum were visually analyzed to determine sacral maturity. Patients were divided into three groups depending on the degree of fusion of the sacral segmental apophyses: "Fused," "Partial," and "Unfused." For each group, SIJ ADC was measured using a linear region-of-interest technique.

RESULTS

Mean ADC values were 690 × 10(-6) mm(2) /s in the fused group, 720 × 10(-6) mm(2) /s in the partial group, and 842 × 10(-6) mm(2) /s in the unfused group. ADC values were significantly higher in the unfused group than in the fused group (P = 0.046). ADC values were also higher in unfused subjects than partially fused subjects (P = 0.074).

CONCLUSION

Joint ADC values are higher in skeletally immature (unfused) patients than in skeletally more mature (fused) patients. ADC values measured in the unfused group overlap with those previously reported in sacroiliitis. These results suggest that ADC measurements in adolescent joints must be interpreted in light of joint maturity. Joint immaturity may lead to misdiagnosis of sacroiliitis, since immature juxta-articular bone may appear similar to inflammation. J. Magn. Reson. Imaging 2016. J. Magn. Reson. Imaging 2016;44:556-564.

Cross-sectional imaging of adult crystal and inflammatory arthropathies

This article highlights the key aspects and current perspectives of the role of cross-sectional imaging in adult crystal and inflammatory arthropathies in adults, briefly discussing CT, and particularly focusing on MRI and US imaging as it supplements the conventional radiography. The role of conventional and advanced MR imaging techniques and imaging findings in this domain is discussed and illustrated with case examples. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article contains images and data, which were collected from patients as a part of a retrospective IRB from the institutional teaching files and informed consent was waived.

Juvenile arthritis: current concepts in terminology, etiopathogenesis, diagnosis, and management

The latest change in terminology from juvenile rheumatoid arthritis (JRA) to juvenile idiopathic arthritis (JIA), established by the International League of Associations for Rheumatology (ILAR), has resulted in some confusion for OMFS and other treating clinicians. JIA comprises a group of systemic inflammatory diseases that result in the destruction of hard and soft tissues in a single or multiple joints. In a significant number of patients, one or both temporomandibular joints (TMJ) are also involved. TMJ disease may be accompanied by pain, swelling, and limitation of motion, as well as mandibular retrognathism, open bite, and asymmetry. The purpose of this article is to provide a review, for the oral and maxillofacial surgeon, of the terminology, etiopathogenesis, diagnosis, and management of children with JIA.

Juvenile idiopathic arthritis and the temporomandibular joint: A comprehensive review

Juvenile idiopathic arthritis is the most common inflammatory rheumatic disease of childhood and represents a series of chronic inflammatory arthritides of unknown cause. Involvement of the temporomandibular joint has been reported in up to 87% of children with juvenile idiopathic arthritis when based on magnetic tomography imaging; it can be asymptomatic and may lead to severe long term complications. In this review a summary of the contemporary literature of imaging of the temporomandibular joint in children with juvenile idiopathic arthritis will be provided, including ultrasound which is a valuable method for guided joint injections, but does not necessarily allow detection of acute inflammation, cone beam computed tomography, which has emerged as a feasible and accurate low-dose alternative as compared to conventional computed tomography to detect destructive change, and magnetic resonance imaging which is considered the method of choice for assessing acute, inflammatory change, although the lack of normative standards remains a challenge in children.

Basic radiological assessment of synovial diseases: a pictorial essay

The synovium is a specialized tissue lining the synovial joints, bursae, and tendon sheaths of the body. It is affected by various localized or systemic disorders. Synovial diseases can be classified as inflammatory, infectious, degenerative, traumatic, hemorrhagic, and neoplastic. Damage in other intraarticular structures, particularly cartilages, generally occurs as a part of pathologic processes involving the synovium, leading to irreversible joint destruction. Imaging has an essential role in the early detection of synovial diseases prior to irreversible joint damage. Obtaining and understanding characteristic imaging findings of synovial diseases enables a proper diagnosis for early treatment. This article focuses on the recent literature that is related with the role of imaging in synovial disease.

The child with joint pain in primary care

Joint pains are a common reason for children to present to primary care. The differential diagnosis is large including some diseases that do not primarily affect the musculoskeletal system. Although the cause for many patients will be benign and self-resolving, in rare cases the diagnosis is associated with long-term morbidity and mortality if not detected early and appropriately treated. These include primary and secondary malignancies, septic arthritis, osteomyelitis, inflammatory arthritis, slipped upper femoral epiphysis (SUFE) and non-accidental injury. We highlight the importance of a thorough history and directed yet comprehensive examination. A diagnostic algorithm is provided to direct primary care physicians' clinical assessment and investigation with the evidence base where available. In many cases, tests are not required, but if there is suspicion of malignancy, infection or inflammatory conditions, laboratory tests including full blood count, blood film, erythrocyte sedimentation rate, C-reactive protein and lactate dehydrogenase help to support or exclude the diagnosis. Autoimmune tests, such as antinuclear antibodies and rheumatoid factor, have no diagnostic role in juvenile idiopathic arthritis; therefore, we advise against any form of 'rheumatological/autoimmune disease screen' in primary care. Imaging does have a place in the diagnosis of joint pains in children, with plain radiographs being most appropriate for suspected fractures and SUFE, whilst ultrasound is better for the detection of inflammatory or infective effusions. The appropriate referral of children to paediatric rheumatologists, oncologists, orthopaedic surgeons and the emergency department are discussed.

Feasibility of diffusion-weighted magnetic resonance imaging in patients with juvenile idiopathic arthritis on 1.0-T open-bore MRI

OBJECTIVE

To evaluate the feasibility of non-invasive diffusion-weighted imaging (DWI) of the knee of children with juvenile idiopathic arthritis (JIA) and, further, to analyze the apparent diffusion coefficient (ADC) levels to distinguish synovium from effusion.

MATERIALS AND METHODS

Standard magnetic resonance imaging of the knee including post-contrast imaging was obtained in eight patients (mean age, 12 years 8 months, five females) using an open-bore magnetic resonance imaging system (1.0 T). In addition, axially acquired echo-planar DWI datasets (b-values 0, 50, and 600) were prospectively obtained and the diffusion images were post-processed into ADC50-600 maps. Two independent observers selected a region of interest (ROI) for both synovium and effusion using aligned post-contrast images as landmarks. Mann-Whitney U test was performed to compare ADC synovium and ADC effusion.

RESULTS

DWI was successfully obtained in all patients. When data of both observers was combined, ADC synovium was lower than ADC effusion in the ROI in seven out of eight patients (median, 1.92 × 10(-3) mm(2)/s vs. 2.40 × 10(-3) mm(2)/s, p = 0.006, respectively). Similar results were obtained when the two observers were analyzed separately (observer 1: p = 0.006, observer 2: p = 0.04).

CONCLUSIONS

In this pilot study, on a patient-friendly 1.0-T open-bore MRI, we demonstrated that DWI may potentially be a feasible non-invasive imaging technique in children with JIA. We could differentiate synovium from effusion in seven out of eight patients based on the ADC of synovium and effusion. However, to select synovium and effusion on DWI, post-contrast images were still a necessity.

Musculoskeletal ultrasound in childhood

Ultrasonography is one of the first line imaging modalities for the evaluation of musculoskeletal disorders in children. This article provides an overview of the most important pathologic entities in which ultrasonography significantly contributes to the diagnostic workup.