Magnetic resonance imaging of the musculoskeletal system in the diagnosis of rheumatic diseases in the pediatric population

Magnetic resonance imaging (MRI) of the musculoskeletal system is an examination increasingly performed for suspected juvenile idiopathic arthritis, chronic nonbacterial osteomyelitis and juvenile idiopathic inflammatory myopathies, as well as other rheumatic diseases of developmental age. T1-, T2- and PD-weighted with or without fat suppression or short tau inversion recovery/turbo inversion recovery magnitude (STIR/TIRM) sequences and post-contrast sequences are evaluated to diagnose pathological changes in the synovial membrane, subchondral bone marrow and surrounding soft tissues. Magnetic resonance imaging allows detection of synovitis, tenosynovitis, bursitis, and enthesitis as well as bone marrow edema and soft tissue edema. Several pediatric-specific MRI scoring systems have been developed and validated to standardize and facilitate the assessment of the extent of the inflammatory process and disease activity in MRI. Early detection of inflammatory changes allows the inclusion of comprehensive pharmacotherapy giving the possibility of permanent remission and objective measurement of the effectiveness of treatment.

Developing standards for MRI evaluation of joints in children with juvenile idiopathic arthritis utilizing the temporomandibular joint as a model

The treatment of a patient with juvenile idiopathic arthritis (JIA) is best monitored with standardized and validated tools to measure joint changes over time. Treatment approaches are best indicated if the clinicians are aware of the structural status of the joint at a given time, especially in anatomically deep joints for which clinical assessment is limited. Magnetic resonance imaging (MRI) is of utmost importance for assessment of deep joints and extra-articular soft tissue of the entire body for which ultrasound may be suboptimal. Because the distinction between pathologic and physiologic joint changes on MRI is key for proper diagnosis and treatment of patients with arthropathies, a comprehensive standardized approach is needed to effectively measure outcomes of growing joints of children with JIA. Such an approach is essential for both clinical assessment and to conduct clinical trials in patients with JIA treated in different centers around the world. To meet this need, several international imaging collaborative research groups have been developing MRI scales over the past years, including the MRI in JIA (JAMRI) special interest group within the Outcome Measures in Rheumatology (OMERACT) research network. This manuscript reviews the efforts of the OMERACT JAMRI working group to generate and validate pediatric MRI scoring systems for different joints in children with JIA that can have ubiquitous utilization anywhere in the world. In particular, it describes the different steps of development and validation of an MRI scale using the TMJ as a model.

MRI of the temporomandibular joint in children with juvenile idiopathic arthritis: protocol and findings

Contrast-enhanced magnetic resonance imaging (MRI) is the technique of choice for diagnosis and monitoring of temporomandibular joint (TMJ) disorders in patients with juvenile idiopathic arthritis (JIA), as it is able to visualize both soft tissue and osteochondral changes. Approximately 40% of children with JIA develop inflammatory and chronic osteochondral changes observable on imaging, which if left untreated can lead to significant facial growth impairment, including facial asymmetry and retrognathia. MRI of the TMJ plays a paramount role in diagnosis and treatment monitoring in JIA since early signs of TMJ involvement are difficult to detect clinically and with physical examination. Findings of TMJ arthritis may be classified into acute and chronic domains. Early or acute manifestations include joint effusion, bone marrow edema, synovial thickening, and increased joint enhancement. With disease progression, there are characteristic osteochondral changes, including deformity of the mandibular condyle with shortening of the mandibular ramus, bone erosions, and disk abnormalities. In this pictorial essay, we describe a consensus MRI protocol for the study of the TMJ and illustrate the degree of normal and pathological MRI findings using currently available MRI scoring systems of the TMJ developed for JIA.

Advances in Musculoskeletal Imaging in Juvenile Idiopathic Arthritis

Over the past decade, imaging of inflammatory arthritis in juvenile arthropathies has significantly advanced due to technological improvements in the imaging modalities and elaboration of imaging recommendations and protocols through systematic international collaboration. This review presents the latest developments in ultrasound (US) and magnetic resonance imaging (MRI) of the peripheral and axial joints in juvenile idiopathic arthritis. In the field of US, the ultra-wideband and ultra-high-frequency transducers provide outstanding spatial resolution. The more sensitive Doppler options further improve the assessment and quantification of the vascularization of inflamed tissues, and shear wave elastography enables the diagnosis of tissue stiffness. Concerning MRI, substantial progress has been achieved due to technological improvements in combination with the development of semiquantitative scoring systems for the assessment of inflammation and the introduction of new definitions addressing the pediatric population. New solutions, such as superb microflow imaging, shear wave elastography, volume-interpolated breath-hold examination, and MRI-based synthetic computed tomography open new diagnostic possibilities and, at the same time, pose new challenges in terms of clinical applications and the interpretation of findings.

Electromyographic Activity of Masticatory Muscles in Subjects with Juvenile Idiopathic Arthritis: A Case—Control Study

The aim of this study was to evaluate the effect of juvenile idiopathic arthritis (JIA) on the activity of masticatory muscles using surface electromyography (sEMG). Forty-one JIA subjects (ten males, thirty-one females; average age 13 years ± 3) and thirty-two healthy control subjects (twenty-seven females, five males; average age 14 years ± 2) were recruited. sEMG of anterior temporalis (TA), masseter (MM), and sternocleidomastoid (SCM) muscles was performed by using the occlusal contact analyzer software called Teethan (BTS S.p.A., Garbagnate Milanese, Milan, Italy). Comparisons between groups were assessed with unpaired t-tests for non-normally distributed data and with Mann–Whitney U tests for normally distributed parameters. The JIA group showed a significant increased percentage overlapping coefficient of TA (POC TA) (p = 0.01) and impact index (IMP) (p = 0.003). No significant differences were observed for the POC MM, POC SCM, percentage overlapping coefficient between posterior and anterior teeth contact (BAR), the torsion index (TORS), and the asymmetry index (ASIM). Masticatory muscles seemed to be slightly affected by JIA. sEMG could be an effective aid in the early clinical detection of TMJ involvement in JIA. Further research is needed to confirm its validity.

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.

Discrete Choice Experiment on a Magnetic Resonance Imaging Scoring System for Temporomandibular Joints in Juvenile Idiopathic Arthritis

OBJECTIVE

To determine the relative importance weights of items and grades of a newly developed additive outcome measure called the juvenile idiopathic arthritis (JIA) magnetic resonance imaging (MRI) scoring system for temporomandibular joints (TMJ, JAMRIS-TMJ).

METHODS

An adaptive partial-profile discrete choice experiment (DCE) survey using the 1000Minds platform was independently completed by members of an expert group consisting of radiologists and non-radiologist clinicians to determine the group-averaged relative weights for JAMRIS-TMJ. Subsequently, an image-based vignette ranking exercise was done, during which experts individually rank-ordered 14 patient vignettes for disease severity while blinded to the weights and unrestricted to JAMRIS-TMJ assessment criteria. Validity of the weighted JAMRIS-TMJ was tested by comparing the consensus-graded, DCE-weighted JAMRIS-TMJ score of the vignettes with their unrestricted image-based ranks provided by the experts.

RESULTS

Nineteen experts completed the DCE survey and 21 completed the vignette ranking exercise. Synovial thickening and joint enhancement showed higher weights per raw score compared to bone marrow items and effusion in the inflammatory domain, while erosions and condylar flattening showed non-linear and higher weights compared to disk abnormalities in the damage domain. The weighted JAMRIS-TMJ score of the vignettes correlated highly with the ranks from the unrestricted comparison method, with median Spearman's rho of 0.92 (intra-quartile range: 0.87-0.95) for the inflammation and 0.93 (0.90-0.94) for the damage domain.

CONCLUSIONS

A DCE survey was used to quantify the importance weights of the items and grades of the JAMRIS-TMJ. The weighted score showed high convergent validity with an unrestricted, holistic vignette ranking method.

Isolated Facet Joint Arthritis in Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is a group of childhood inflammatory arthropathies which has variable clinical presentations and can affect multiple joints including the spine. Arthritis in facet joints is rare and very unusual to be the only presentation of JIA. We report a 16-year-old female who presented with back pain and stiffness, in which CT of the lumbar spine showed evidence of facet joint erosion and pelvis MRI showed facet joint arthritis consistent with juvenile idiopathic arthritis. 

Juvenile idiopathic arthritis in the lumbosacral spine of a toddler: Periarticular osteopenia in a rare location

Juvenile idiopathic arthritis (JIA) is a group of childhood inflammatory arthropathies that affects multiple joints including the spine, particularly the cervical region. There is paucity of literature regarding JIA in the lumbosacral spine; the few published studies which discuss imaging findings in the lumbosacral spine only include cohorts of older children and adolescents. We present a 22-month-old boy with refusal to walk, in which plain radiographs and contrast-enhanced magnetic resonance imaging of the lumbosacral spine suggested a diagnosis of JIA.

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.

Comprehensive Assessment of Orofacial Health and Disease Related Parameters in Adolescents with Juvenile Idiopathic Arthritis-A Cross-Sectional Study

Background: The aim of this cross-sectional study was to investigate oral health and functional status of adolescents with juvenile idiopathic arthritis (JIA) and its possible link to disease specific parameters. Methods: Patients with JIA were recruited (November 2012–October 2014) and disease specific information was extracted from patients’ records. Oral examination included: dental findings (decayed-, missing- and filled-teeth-index (dmf-t/DMF-T)), gingival inflammation (papilla-bleeding-index (PBI)) and periodontal screening index (PSI). Functional examination followed Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Additionally, modified Helkimo’s Clinical Dysfunction Index and radiographic scoring were recorded. Results: 59 JIA patients were included. The mean dmf-t/DMF-T was 2.6. Only one patient showed no signs of gingival inflammation, while 57.6% had a maximum PSI of 2 or less. Positive functional findings were assessed clinically in more than half of the patients. Major diagnosis by RDC/TMD was osteoarthrosis. Patients with at least one positive anamnestic or clinical functional finding revealed significantly higher radiographic scores (CI = 0.440, p = 0.022). Patients with increased c-reactive-protein had a significantly higher PBI (Z = –2.118, p = 0.034) and increased radiographic scores (CI = 0.408, p = 0.043). Conclusions: Adolescents suffering from JIA show high levels of caries experience and gingival inflammation. Temporomandibular joint dysfunction is often seen in JIA patients. Consequently, special dental care programs would be recommendable.

TMJ Dysfunctions Systemic Implications and Postural Assessments: A Review of Recent Literature

Cases of correlations between posture and the temporomandibular joint have long been reported in the literature. In particular, occlusal anomalies, and therefore malocclusion, could have negative implications for the spine. The objective of this study was to review the literature and bring to light any correlations between temporomandibular joints (TMJ) and posturology. The literature search was conducted in the PubMed and Embase scientific search engines with the aim of obtaining the most possible results in the initial search, the number of results initially obtained was 263. Subsequently, the inclusion and exclusion criteria were reduced first to 83 and subsequently to manual analysis of the articles, those included remained only 11. The results show a correlation between anomalies of the TMJ and dysfunctions of the vertebral column. Not all the articles considered are in agreement with each other regarding epidemiological data, but surely this study can represent an important starting point for a much more careful evaluation of the dental patient and at the same time for the request for counseling by a dentist in case of postural abnormalities.

Value of dedicated small-field-of-view sacroiliac versus large-field-of-view pelvic magnetic resonance imaging for evaluating pediatric sacroiliitis

BACKGROUND

Optimized MRI parameters can be leveraged to improve signal intensity, accelerate imaging acquisition and increase resolution. Higher-resolution imaging with a small field of view (FOV) has been proposed as standard practice for investigating sacroiliac (SI) joints, but the improvement in disease detection and characterization over pelvic imaging with large FOV has not been established.

OBJECTIVE

The purpose of this study was to compare dedicated MR images of the SI joints with survey imaging (large-FOV pelvic MRI) for detecting sacroiliitis.

MATERIALS AND METHODS

Fifty-eight pediatric patients suspected of having sacroiliitis underwent dedicated sacroiliac joint and survey pelvic imaging at the same imaging session. We independently evaluated the small- and large-FOV image data sets for presence or absence of sacroiliitis, e.g., bone marrow edema, erosions and synovitis. We used nonparametric statistical tests to compare lesion scores for severity of inflammation. We created test characteristics for the survey pelvic images (low-resolution images of the sacroiliac joints) using dedicated sacroiliac images (small-FOV, high-resolution images) as the gold standard.

RESULTS

Dedicated sacroiliac small-FOV MRI detected more sacroiliitis compared to survey pelvic imaging with large FOV (χ²=6.125, P=0.013). Readers detected significantly more features of inflammation on small- compared to large-FOV images, e.g., erosions (P=0.039), synovitis (P=0.009), sclerosis (P=0.017) and osteitis (P=0.001). Test characteristics for pelvic large-FOV imaging were sensitivity=0.76, specificity=1.00, positive predictive value = 1.00 and negative predictive value = 0.75.

CONCLUSION

This study provides test characteristics for survey pelvic MRI with lower-resolution large-field-of-view images as a screening tool for detecting sacroiliitis. Pelvic screening studies with large FOV have lower sensitivity, and dedicated sacroiliac MRI with small FOV is superior in detecting sacroiliitis when compared to pelvic screening MRI.

Temporomandibular joint damage in juvenile idiopathic arthritis: Diagnostic validity of diagnostic criteria for temporomandibular disorders

BACKGROUND

Diagnostic criteria reported in the expanded taxonomy for temporomandibular disorders include a standardised clinical examination and diagnosis (DC/TMD 3.B) of temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA); however, their validity is unknown.

OBJECTIVES

To assess the validity of DC/TMD 3.B for the identification of TMJ damage in JIA-patients, using magnetic resonance imaging (MRI) as gold standard, and to investigate the relation between clinical findings and TMJ damage.

METHODS

Fifty consecutive JIA patients (9-16 years) were recruited. DC/TMD 3.B were compared with TMJs MRI (100 TMJs) performed maximum at 1 month from the visit. The severity of TMJ damage was scored in four grades. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), logistic regression models with odds ratio of DC/TMD 3.B and clinical findings respect to MRI were calculated.

RESULTS

The DC/TMD 3.B were inadequate in the identification of TMJ damage (sensitivity = 0.15, specificity = 0.92, PPV = 0.85, NPV = 0.28, P = 0.350). Chin deviation and TMJ crepitus were associated with worse TMJ damage (P = 0.006; P = 0.034). Reduced mouth opening (OR = 3.91, P = 0.039) and chin deviation (OR = 13.7, P = 0.014) were associated with the presence of TMJ damage. Combining "pain" (history of pain, TMJ pain, pain during movements) and "function" (TMJ crepitus, reduced mouth opening, chin deviation) clinical findings, the sensitivity and the specificity were 0.88 and 0.54.

CONCLUSION

DC/TMD 3.B present a low sensitivity to diagnose TMJ damage. Chin deviation, reduced mouth opening and TMJ crepitus are associated with TMJ damage. We suggest combining "pain" and "function" findings for the evaluation of TMJ damage in JIA patients.

Developing a reference MRI database for temporomandibular joints in healthy children and adolescents

BACKGROUND

Recognition of normal temporomandibular joints (TMJs) is essential to assess arthropathic changes. Few, if any, prior studies have evaluated the morphological appearance of growing TMJs by magnetic resonance (MR) examinations in the pediatric population.

OBJECTIVE

This study aimed to determine normative osseous appearance of growing TMJs according to age and gender, both qualitatively and quantitatively, concerning structural and bone marrow changes.

MATERIALS AND METHODS

From 1,036 MR scans screened, one joint was included from each of 157 patients (76% female; 2-18 years) presenting with at least one normal-appearing TMJ was included. Quantitatively, mandibular condyle was characterized by measuring the following: (i) head-neck angle, (ii) anteversion angle, (iii) condylar dimensions (mediolateral, craniocaudal and anteroposterior [AP]) and (iv) condylar volume. Furthermore, qualitative categorization of condylar shape, into one of three types, and condylar bone marrow type was performed.

RESULTS

The head-neck angle significantly correlated with age (bivariable regression β =0.60, P<0.001), indicating an increase of 1.6 degrees per year. Except for AP diameter of condyles, all other mandibular dimensions and condylar volume increased with age (β =0.20-0.59, P≤0.001-0.004). Significant age difference was observed among the different condylar shapes (P<0.001), indicating a change from rounded head without anterior tilt to rectangular head with anterior tilt. Lastly, mandibular condylar size, measured by volume and by AP and mediolateral dimensions, appeared larger in males.

CONCLUSION

The morphology of the mandibular condyles changes with age. During development, the shape of the condyles changes from round to rectangular in contour with the development of the anterior condylar tilt, as measured by the head-neck angle.

Toward Establishing a Standardized Magnetic Resonance Imaging Scoring System for Temporomandibular Joints in Juvenile Idiopathic Arthritis

OBJECTIVE

The temporomandibular joints (TMJs) are frequently affected in children with juvenile idiopathic arthritis (JIA). Early detection is challenging, as major variation is present in scoring TMJ pathology on magnetic resonance imaging (MRI). Consensus-driven development and validation of an MRI scoring system for TMJs has important clinical utility in timely improvement of diagnosis and serving as an outcome measure. We report on a multi-institutional collaboration toward developing a TMJ MRI scoring system for JIA.

METHODS

Seven readers independently assessed MRI scans from 21 patients (42 TMJs, from patients ages 6-16 years) using 3 existing MRI scoring systems from American, German, and Swiss institutions. Reliability scores, scoring system definitions, and items were discussed among 10 JIA experts through 2 rounds of Delphi surveys, nominal group voting, and subsequent consensus meetings to create a novel TMJ MRI scoring system.

RESULTS

Average-measure absolute agreement intraclass correlation coefficients (avICCs) for the total scores of all 3 scoring systems were highly reliable at 0.96 each. Osteochondral items showed higher reliability than inflammatory items. An additive system was deemed preferable for assessing minor joint changes over time. Eight items were considered sufficiently reliable and/or important for integration into the consensus scoring system: bone marrow edema and enhancement (avICC 0.57-0.61, smallest detectable difference [SDD] ± 45-63% prior to redefining), condylar flattening (avICC 0.95-0.96, SDD ± 23-28%), effusions (avICC 0.85-0.88, SDD ± 25-26%), erosions (avICC 0.94, SDD ± 20%), synovial enhancement and thickening (previously combined, avICC 0.90-0.91, SDD ± 33%), and disk abnormalities (avICC 0.90, SDD ± 19%).

CONCLUSION

A novel TMJ MRI scoring system was developed by consensus. Further iterative refinements and reliability testing are warranted in upcoming studies.

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.

Qualitative and semi-quantitative assessment of temporomandibular joint MRI protocols for juvenile idiopathic arthritis at 1.5 and 3.0T

OBJECTIVE

Temporomandibular joints (TMJs) frequently develop silent inflammatory and osteochondral changes in children with juvenile idiopathic arthritis. Data-driven recommendations for TMJ imaging protocol are needed to reduce measurement error and scanning time. This study compares the impact of different protocols, imaging coils, and magnet strength on the reliability of image assessment and the subjective quality of images.

MATERIALS AND METHODS

Three groups of bilateral TMJ MR studies were retrospectively collected from two institutions, including 24 1.5T and 19 3.0T studies using dedicated TMJ surface coils, and 23 1.5T studies with head coil. Post-contrast sequences were re-compiled from the full protocol to create minimum protocol studies for the three groups. Two radiologists and two non-radiologists first scored the three minimum protocol images according to pre-specified definitions, then scored the full protocol images. Minimum-to-full protocol agreement, inter-reader agreement, and subjective item visibility scores were assessed.

RESULTS

With dedicated TMJ dual surface coils, minimum-vs-full protocol agreement was moderate to good (0.5-0.8 intraclass correlation coefficients or kappa) for most items, and was not influenced by the magnet strength. Inter-reader reliability was more significantly influenced by the imaging coil and reader's training background than by protocol length or magnet strength differences. Sagittal and coronal planes weighted on PD, T2 Fat Suppressed and T1 Fat Suppressed -postcontrast adequately visualized all the different features, whereas the axial plane was more limited to visualizing synovium.

CONCLUSION

Inter-reader reliability and qualitative measure of image quality improved more consistently with the coil offering the higher resolution, rather than increased magnet strength.

Which MR sequences should we use for the reliable detection and localization of bone marrow edema in spondyloarthritis?

Objectives

To assess the diagnostic confidence in detecting and localizing areas of bone marrow edema in the sacroiliac joint of patients with suspected spondyloarthritis using a single-plane method and comparing it with multiplanar unenhanced and enhanced methods.

Materials and methods

Patients with clinical suspicion of spondyloarthritis undergoing an MRI of the sacroiliac joint were included in this retrospective study. To assess sacroiliitis, three methods were applied: single-plane (i.e., para-coronal STIR alone), multiplanar unenhanced (i.e., para-coronal STIR and para-axial PD-fs), and multiplanar enhanced method (i.e., para-coronal and para-axial post-contrast T1-fs). Two 4-point scales were used to evaluate, respectively, the diagnostic confidence in detection and localization of bone marrow edema. The distribution of certain and uncertain rating according to signal intensity and size of the lesions was also calculated.

Results

Seventy-four patients met the inclusion criteria. Both multiplanar methods increased the diagnostic confidence in detection (p < 0.001) and localization (p < 0.001) of sacroiliitis; no significant difference occurred between the multiplanar unenhanced and enhanced methods (p = 0.405 and p = 1.00, respectively, for detection and localization). A statistically significant difference between the distributions of certain and uncertain rating for detection based on the size and signal intensity of each lesion emerged (p = 0.006 and p < 0.001, respectively), whereas no statistically significant difference occurred for the confidence of localization (p = 0.452 and p = 0.694, respectively).

Conclusions

The multiplanar methods increased the diagnostic confidence in detection and localization of sacroiliitis. The absence of a significant difference between the proposed unenhanced and enhanced methods suggests that contrast medium is not mandatory for the detection of sacroiliitis.

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.

Contemporary management of TMJ involvement in JIA patients and its orofacial consequences

Juvenile idiopathic arthritis is the most common chronic rheumatic condition during childhood. Temporomandibular joint arthritis is frequently asymptomatic. When it takes place during childhood, it may affect condylar growth; therefore, these children are at risk of unfavorable long-term outcomes from the associated joint damage. The etiology is not completely understood, but it is considered as multifactorial with both genetic and environmental factors involved.

The standardized examination and imaging protocols serve important purpose to diagnose temporomandibular joint (TMJ) arthritis not only to establish an early interventional strategy but also to assess craniofacial growth and the progression of signs and symptoms in those patients. Although the treatment of juvenile idiopathic arthritis (JIA) has changed dramatically over the last decades due to new therapeutic options, TMJ arthritis still can develop during the course of the disease. In clinical experience, TMJs appear to respond less well to the standard of care used to treat other joints. More individualized approach to the patient’s treatment serves as the main goal of personalized medicine. It could be achieved by adopting new methods of medical imaging such as conebeam computer tomography as well as developing reliable biomarkers which may assist with predicting disease type, course, or severity and predicting response to medication.

This article provides an overview of current information on orofacial complications in JIA and its management. Based on information provided in this review, more precise diagnosis, proper tools for recognizing people at risk, and more efficient treatment approaches could be implemented. This may lead to more personalized treatment management strategies of TMJ complications of JIA patients.

Clinical predictors of temporomandibular joint arthritis in juvenile idiopathic arthritis: A systematic literature review

AIM

To assess the level of evidence for subjective and objective parameters in clinical orofacial examination and determine if predictors for temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) patients exist in the current literature.

METHOD

A comprehensive systematic electronic search strategy was performed in all major medical databases in June 2015. Studies were selected independently by two reviewers in accordance with a prespecified protocol and a risk of bias assessment for all included studies. Subjective examination outcome measures assessed were pain, decreased TMJ function, and TMJ sounds. The objective outcome measures assessed were maximal incisor opening, mandibular asymmetric opening, condylar translation, protrusion, myofascial pain on palpation, facial asymmetry, and micro- or retrognathism.

RESULTS

The electronic database search identified 345 unique citations. After application of our strict, predefined inclusion and exclusion criteria, 21 articles were included and data extracted. The study heterogeneity did not allow for meta-analyses. No singular outcome measure can be suggested as a predictor of TMJ involvement in JIA, as sensitivity and/or specificity is too low compared to contrast-enhanced magnetic resonance imaging.

CONCLUSION

The current low level of evidence and study heterogeneity do not allow us to conclude on singular clinical outcome measures. To increase study comparability, we call for a standardized terminology and evidence-based guidelines for clinical orofacial examination parameters in JIA patients.

Management of severe sleep apnea secondary to juvenile arthritis with temporomandibular joint replacement and mandibular advancement

Variations affecting the growth centers can severely affect the normal formation and subsequent function of vital musculoskeletal structures. We report a case of bilateral condylar atrophy with a history of juvenile arthritis (JA) resulting in progressive obstructive sleep apnea (OSA) in adulthood. In addition to this, the case report emphasizes the role of temporomandibular joint replacement and advancement of the mandible to correct progressive OSA secondary to idiopathic JA. Computed tomography revealed micrognathia, condylar hypoplasia, and decreased pharyngeal airway space. The resultant increase in the retrolingual-pharyngeal airway space following the surgery, helped to completely resolve the presenting symptoms. It is hoped that the described technique could be used in similar cases with a predictable outcome.

Effect of methotrexate on the mandibular development of arthritic rabbits

INTRODUCTION

Juvenile idiopathic arthritis affecting the temporomandibular joint (TMJ) can cause severe disturbances of the mandibular development. Methotrexate (MTX) is often administered as a common used remission-inducing agent to treat this disease. The aim of this study was to investigate the effect of low dose MTX on the mandibular growth in arthritic rabbits.

SUBJECTS AND METHODS

Eighteen 10-week-old female New Zealand white rabbits were randomly assigned to three groups with six animals in each group. After being sensitized to ovalbumin (OA), the first and the second group received intra-articular injections with OA. The first group remained untreated, the second was treated by weekly injections of MTX. Cephalograms were taken from each animal at 10, 13, 16, 19, and 22 weeks of age and six mandibular distances measured.

RESULTS

All distances showed an increase between 10 and 20 per cent, whereas growth was more accentuated in the sagittal dimension. Significant differences in the overall growth could be observed between the arthritic and the control animals and less accentuated between the arthritic and the MTX animals. In contrast, existing differences between the groups were not significant during the intervals, but time had the greatest influence on mandibular growth.

CONCLUSIONS

MTX seems to have a positive impact on growth in rabbits suffering from experimental arthritis of the TMJ.

Effect of methotrexate upon antigen-induced arthritis of the rabbit temporomandibular joint

BACKGROUND

Juvenile idiopathic arthritis (JIA) of the temporomandibular joint (TMJ) can cause severe growth disturbances of the craniomandibular system. Antigen-induced arthritis (AIA) of the rabbit TMJ is simulating the inflammatory process of the TMJ in JIA. The aim of this study was to investigate the effect of a systemic administration of methotrexate (MTX) on AIA in rabbits by means of three different histological staining methods.

METHODS

After sensitization, a bilateral arthritis of the TMJ was induced by an intra-articular administration of ovalbumin in 12 New Zealand white rabbits aged 10 weeks. From the 13th week of age, six of the 12 rabbits received weekly intramuscular injections of MTX, and the other six animals remained without therapy. Another six animals served as controls, receiving no treatment or intra-articular injections at all. After euthanasia at the age of 22 weeks, all TMJs were retrieved en bloc. Sagittal sections were cut and stained with haematoxylin-eosin (H-E), Safranin-O for the evaluation of the Mankin score and tartrate-resistant acid phosphatase (TRAP).

RESULTS

In the arthritis group, a chronic inflammation with degeneration of the articular cartilage was visible. In the MTX group, the signs of cartilage degeneration were significantly reduced compared with the arthritis group. In contrast, the joints in the control group were inconspicuous. A correlation between the Mankin score and TRAP-positive cells could be found.

CONCLUSIONS

Systemic administration of MTX seems to have a positive effect upon the inflammatory process in the rabbit TMJ but fails to eliminate the sign of arthritis completely.