Recommendations of the ESSR Arthritis Subcommittee for the Use of Magnetic Resonance Imaging in Musculoskeletal Rheumatic Diseases

Zero Echo Time and Similar Techniques for Structural Changes in the Sacroiliac Joints

Spondyloarthritis (SpA) encompasses inflammatory disorders affecting the axial skeleton, with sacroiliitis as a hallmark feature of axial SpA (axSpA). Imaging plays a vital role in early diagnosis and disease monitoring. Magnetic resonance imaging (MRI) is the preferred modality for detecting early inflammatory changes in axSpA, whereas structural lesions are better visualized using computed tomography (CT). However, synthetic computed tomography (sCT), a technique that generates CT-like images from MRI data, including deep learning methods, zero echo time, ultrashort echo time, and gradient-recalled echo sequences, has emerged as an innovative tool. It offers detailed anatomical resolution without ionizing radiation and combines the advantages of both, MRI and CT, by enabling the simultaneous evaluation of inflammatory and structural lesions. This review explores the potential role of MRI-based sCT in assessing structural changes in the sacroiliac joints, particularly in the context of axSpA, discussing conventional imaging and highlighting the potential of sCT to enhance early detection and monitoring of sacroiliitis.

Multimodal imaging of structural damage and inflammation in psoriatic arthritis: a comparison of DMARD-naive and DMARD-failure patients

OBJECTIVES

To compare inflammatory and structural differences in active PsA between DMARD-naive and DMARD-failure patients using diverse imaging approaches for future analyses. Additionally, to explore the influence of patient characteristics (clinical and demographic variables) on imaging findings.

METHODS

Of the 80 patients included from the first cohort of the ongoing multicentre TOFA-PREDICT trial, 40 were DMARD-naive and 40 were DMARD-failure (csDMARD failure; one prior bDMARD excluding etanercept was allowed), all meeting classification criteria for PsA with a minimum disease duration of eight weeks. Baseline conventional radiographs of hands and feet, MRIs of both ankles, and whole-body [18F]-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) were evaluated for inflammatory and structural imaging parameters, including Sharp-van der Heijde (SHS), Heel Enthesitis Magnetic Resonance Imaging Scoring System (HEMRIS) and Deauville synovitis scoring. Differences between groups and the influence of patient characteristics were examined with multiple linear regression.

RESULTS

At baseline, patient characteristics were similar between groups. Imaging parameters showed limited inflammation and structural damage. Inflammatory imaging parameters were not significantly different (P > 0.200). Among structural parameters, only HEMRIS Achilles tendon structural damage was significantly different (P = 0.024, R2 = 0.071) and SHS Joint Space Narrowing was not statistically significant (P = 0.050, R2 = 0.048) with higher values for both in DMARD failures. After correction of patient characteristics, these differences in imaging disappeared (both P > 0.600).

CONCLUSION

At baseline, PsA patient groups were comparable concerning structural and inflammatory imaging parameters, especially after correcting for patient characteristics. Thus, DMARD-naive and DMARD-failure patient groups may be combined in future PsA progression and treatment decision studies.

TRIAL REGISTRATION

www.clinicaltrialsregister.eu. EudraCT: 2017-003900-28.

Spondyloarthritis endgame: MRI versus BoneMRI in sacroiliitis

The Assessment in SpondyloArthritis International Society (ASAS) classification criteria characterize sacroiliitis by active inflammation and structural lesions. Detection of lesions such as bone marrow edema, joint surface erosions and ankylosis is important, because progressing treatment options benefit from early diagnosis and detailed treatment response monitoring. Recent technological advancements have made various imaging modalities available to assess these findings, i.e., various sorts of CT (low dose, dual energy, etc.), MRI and BoneMRI. BoneMRI is an advanced technique where CT-like images are reconstructed from a dedicated MRI sequence, opening opportunities to better characterize structural lesions than on a classic MRI study. The scope of this review is to provide an overview of the pros and cons of MRI and BoneMRI in sacroiliitis and demonstrate the inherent added value of BoneMRI towards state-of-the-art routine MRI sequences.

Standardized uptake value-based analysis of two-phase whole-body bone tomoscintigraphies recorded with a high-speed 360° CZT camera in patients with known or suspected inflammatory arthritis

PURPOSE

360° CZT-cameras provide whole-body bone SPECT/CT recordings at delayed (DEL) and blood-pool (BP) phases with short recording times but long visual analysis times. This study aims to determine whether a standardized uptake value (SUV)-based detection of inflammatory arthritis (IA) could facilitate this analysis.

METHODS

We included 72 patients with known or suspected IA who underwent two-phase whole-body bone SPECT/CT after 550-650 MBq [99mTc]Tc-HDP injection. Forty-eight patients also had ultrasound (US) for peripheral IA, and 42 had MRI for axial IA. The skeleton was segmented into 26 joint areas and analyzed by trained observers using a visual consensus methodology and SUVmax measurements.

RESULTS

A total of 1836 joint areas were analyzed, including 1126 peripheral ones (limb joints excluding hips and shoulders). SUVmax was predictive of visually abnormal SPECT joints with high areas under receiver-operating-characteristic (ROC) curves for non-peripheral (BP-SPECT: 0.941 ± 0.017, DEL-SPECT: 0.910 ± 0.014) and especially peripheral (BP-SPECT: 0.980 ± 0.005, DEL-SPECT: 0.939 ± 0.012) joints. An SUVmax threshold-based prediction of visual SPECT abnormalities had high negative predictive values (BP-SPECT: 99.2% (1479/1491), DEL-SPECT: 97.2% (1333/1372)) but low positive predictive values (BP-SPECT: 35.1% (121/345), DEL-SPECT: 51.2% (237/463)). MRI- and US-defined IA were best predicted by a visually abnormal BP-SPECT due to higher specificities than SUVmax thresholds (all p < 0.05).

CONCLUSION

On two-phase whole-body bone SPECT/CT, an SUVmax-based IA detection may not replace the conventional visual method. However, given the high negative predictive values provided by SUVmax thresholds, the time-consuming visual analysis of SPECT/CT slices could be confined to the small proportion of joints exceeding these thresholds.

Diagnosis of Sacroiliitis Through Semi-Supervised Segmentation and Radiomics Feature Analysis of MRI Images

BACKGROUND

Sacroiliitis is a hallmark of ankylosing spondylitis (AS), and early detection plays an important role in managing the condition effectively. MRI is commonly used for diagnosing sacroiliitis, traditional methods often depend on subjective interpretation or limited automation which can introduce variability in diagnoses. The integration of semi-supervised segmentation and radiomics features may reduce reliance on expert interpretation and the need for large annotated datasets, potentially enhancing diagnostic workflows.

PURPOSE

To develop a diagnostic model for sacroiliitis and bone marrow edema (BME) using semi-supervised segmentation and radiomics analysis of MRI images.

STUDY TYPE

Retrospective cohort study.

POPULATION

A total of 257 patients (161 males, 93 females; age 11-74 years), including 155 sacroiliitis and 175 BME patients. A total of 514 sacroiliac joint (SIJ) MRI images are analyzed, with 359 used for training and 155 for testing.

FIELD STRENGTH/SEQUENCE

3.0 T, spin echo T1-weighted imaging (T1WI) and short-tau inversion recovery (STIR).

ASSESSMENT

SIJ segmentation is automated using the semi-supervised segmentation-based Unimatch framework. Manual delineation of SIJ regions of interest (ROIs) on T1WI images by an experienced radiologist (W.M., 10-year experience) served as the reference standard for segmentation performance evaluation. Radiomics features from T1WI and STIR are used to train machine learning models, including support vector machine (SVM), logistic regression (LR), and light gradient boosting machine (LightGBM), for sacroiliitis and BME detection. Performance is assessed using area under the curve (AUC), sensitivity, specificity, and accuracy. The Dice coefficient is used to assess the performance of the semi-supervised segmentation model on SIJ segmentation.

STATISTICAL TESTS

Performance is evaluated using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULT

The Unimatch model achieves an average Dice coefficient of 0.859 for SIJ segmentation. AUCs for sacroiliitis detection are 0.84 (LR), 0.86 (SVM), and 0.78 (LightGBM), while for BME detection, AUCs are 0.73 (LR), 0.76 (SVM), and 0.70 (LightGBM).

DATA CONCLUSION

This study demonstrates that semi-supervised segmentation combined with radiomics features and machine learning models provides a promising approach for diagnosis of sacroiliitis and BME.

PLAIN LANGUAGE SUMMARY

This study aimed to improve the diagnosis of sacroiliitis and bone marrow edema in patients with ankylosing spondylitis. The researchers used a method that automatically segments MRI images and analyzes features from those images. By applying machine learning, they created models to help detect sacroiliitis and bone marrow edema more accurately. The results show that this approach can effectively assist in identifying these conditions, with the best accuracy for sacroiliitis and bone marrow edema reaching 81.2% and 74.2%, respectively. This method could help doctors make better decisions, offering a promising tool for improving diagnosis in clinical settings.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Standardized reporting of spine and sacroiliac joints in axial spondyloarthritis MRI: from the ESSR-Arthritis Subcommittee

OBJECTIVES

Apply a modified Delphi-based approach and produce a practical, radiology-specific set of definitions for interpretation and standardization of the multiple MRI findings in axial spondyloarthritis (ax-SpA), specifically to aid the general radiologist with a musculoskeletal interest, working with gold standard basic MRI protocols.

MATERIALS AND METHODS

We report the results of a modified Delphi-based consensus of 35 experts from 13 countries in the Arthritis Subcommittee of the European Society of Musculoskeletal Radiology (ESSR). Seventeen definitions were created (i.e., nine for the spine and eight for the sacroiliac joint) and two Delphi rounds were conducted on an electronic database, collated and revised by the project leader with agreement. Group leads were appointed for each definition following the first round. Final definitions included only those that reached a consensus > 80%; if > 50% agreed on exclusion consensus, definitions were excluded. Final results have been shared during the Arthritis meeting at the Annual ESSR Congress.

RESULTS

Fourteen definitions, eight for the spine and six for the sacroiliac joint were agreed for standardized reporting. Andersson's, anterior corner sclerotic and costovertebral joint inflammatory lesions of the spine, with active and non-active erosions, and fat metaplasia of the sacroiliac joint reaching the highest consensus (≥ 95%). More than 50% of the experts agreed to exclude joint space inflammation in the sacroiliac joint and tissue backfill. Syndesmophytes reached 76% agreement.

CONCLUSIONS

Agreed definitions by expert radiologists using a modified Delphi process, should allow standardized actionable radiology reports and clarity in reporting terminology of ax-SpA.

CLINICAL RELEVANCE STATEMENT

The proposed definitions will support reporting from musculoskeletal and general radiologists working with gold-standard basic MRI, improve confidence in lesion assessment, and standardize terminology to provide actionable reports on MRI in patients with ax-SpA.

KEY POINTS

Experts applied a modified Delphi method to optimize the definitions of MRI findings of ax-SpA. After two Delphi rounds and one in-person meeting, fourteen definitions reached the agreement threshold. These consensus-based definitions will aid in actionable reporting specifically for the general radiologist with a musculoskeletal interest.

The 'Tree trunk and root' model: key imaging findings may anatomically differentiate axial psoriatic arthritis and DISH from axial spondyloarthropathy

Variable axial skeleton inflammation and axial skeleton tissue remodelling with aberrant ligamentous soft-tissue ossification occurs across the axial spondyloarthritis (ax-SpA) axial psoriatic arthritis (ax-PsA) and the diffuse idiopathic skeletal hyperostosis (DISH) spectrum. In this article, we show how imaging has resulted in an enthesis-centric model for different disease pathology compartmentalisation or a 'root and trunk' model for pathological process development. Whilst ankylosing spondylitis is predominantly characterised by early entheseal bony anchorage-related osteitis (root inflammation) and DISH is characterised by ligamentous soft-tissue ossification, ax-PsA is more heterogenous. Whilst ax-PsA may share an identical osteitis pattern to ax-SpA, a substantial proportion of ax-PsA cases have a soft tissue or tree trunk pathology that manifests as back pain with lack of osteitis but prominent ligamentous trunk ossification at later stages. We illustrate this using different imaging modalities to create a base for imaging research to elucidate this pattern of pathology.

Spine and Sacroiliac Joint Involvement in Newly Diagnosed Patients With Inflammatory Bowel Disease: Clinical and MRI Findings From a Population-Based Cohort

INTRODUCTION

In patients with inflammatory bowel disease (IBD), co-occurring spondyloarthritis (SpA) leads to poorer outcomes and impaired quality of life, highlighting the importance of early detection and effective treatment. This is the first study to assess the prevalence and distribution of axial symptoms and magnetic resonance imaging (MRI)-detected involvement of the spine and sacroiliac joints (SIJs) in early IBD.

METHODS

Newly diagnosed patients with IBD from a prospective, population-based cohort were consecutively recruited. Rheumatological interview, clinical, ultrasound, and MRI assessment for SIJ and spine inflammatory and structural lesions were made using validated scoring methods and consensus definitions of axial SpA (axSpA).

RESULTS

Of 110 patients (ulcerative colitis: 70, Crohn's disease: 40, mean age of 42 years, and 40% male), 48 (44.9%) reported back and/or buttock pain, and 10 (9.1%) had inflammatory back pain. Seventeen (16.7%) patients had MRI findings indicative of axSpA; only 10 of these patients had axial symptoms. Inflammatory MRI lesions were present in SIJs and the spine of 27 (26.5%) and 30 (30.3%) patients, respectively. The Assessment of SpondyloArthritis International Society classification criteria for axSpA were met in 11 (10%) cases. MRI findings typical of axSpA were associated with peripheral joint and entheseal inflammation detected by ultrasound ( P = 0.04). No differences in clinical or imaging findings were found between patients with ulcerative colitis and Crohn's disease.

DISCUSSION

One-in-6 newly diagnosed patients with IBD had MRI findings indicative of axSpA. As 40% of these patients were asymptomatic, this suggests that axSpA is underdiagnosed in early IBD. Multidisciplinary collaboration is essential to ensure early detection of axial inflammation and to enable optimal therapy preventing future structural damage and disability.

Ultrasound of the Foot and Ankle in Peripheral Spondyloarthritis

Seronegative spondyloarthritis (SpA) is an umbrella term that includes ankylosing spondylitis (AS), psoriatic arthritis, reactive arthritis, and arthritis related to inflammatory bowel disease. Apart from AS, these other conditions predominantly affect the appendicular skeleton. Both the foot and ankle are frequently involved peripheral joints. According to the latest Assessment of Spondyloarthritis International Society criteria, imaging is a key way to diagnose peripheral seronegative SpA. Common imaging features are enthesitis, synovitis, tenosynovitis, erosive and bone-proliferative changes in the affected joints, and effusion.Although magnetic resonance imaging is the gold standard technique, ultrasound (US) is a cost-effective imaging method that can readily detect the features just described. Additionally, it can semi-quantify inflammatory changes, helping in treatment and dose modifications. Imaging-guided procedures, such as biopsies and steroid injections, are routinely performed using US. Furthermore, US can easily be deployed at outpatient rheumatology clinics, making it an ideal point-of-care investigation.

Development of international consensus on a standardised image acquisition protocol for diagnostic evaluation of the sacroiliac joints by MRI: an ASAS-SPARTAN collaboration

BACKGROUND

A range of sacroiliac joint (SIJ) MRI protocols are used in clinical practice but not all were specifically designed for diagnostic ascertainment. This can be confusing and no standard diagnostic SIJ MRI protocol is currently accepted worldwide.

OBJECTIVE

To develop a standardised MRI image acquisition protocol (IAP) for diagnostic ascertainment of sacroiliitis.

METHODS

13 radiologist members of Assessment of SpondyloArthritis International Society (ASAS) and the SpondyloArthritis Research and Treatment Network (SPARTAN) plus two rheumatologists participated in a consensus exercise. A draft IAP was circulated with background information and online examples. Feedback on all issues was tabulated and recirculated. The remaining points of contention were resolved and the revised IAP was presented to the entire ASAS membership.

RESULTS

A minimum four-sequence IAP is recommended for diagnostic ascertainment of sacroiliitis and its differential diagnoses meeting the following requirements. Three semicoronal sequences, parallel to the dorsal cortex of the S2 vertebral body, should include sequences sensitive for detection of (1) changes in fat signal and structural damage with T1-weighting; (2) active inflammation, being T2-weighted with fat suppression; (3) bone erosion optimally depicting the bone-cartilage interface of the articular surface and (4) a semiaxial sequence sensitive for detection of inflammation. The IAP was approved at the 2022 ASAS annual meeting with 91% of the membership in favour.

CONCLUSION

A standardised IAP for SIJ MRI for diagnostic ascertainment of sacroiliitis is recommended and should be composed of at least four sequences that include imaging in two planes and optimally visualise inflammation, structural damage and the bone-cartilage interface.

Clinical information on imaging referrals for suspected or known axial spondyloarthritis: recommendations from the Assessment of Spondyloarthritis International Society (ASAS)

OBJECTIVES

This study aims to establish expert consensus recommendations for clinical information on imaging requests in suspected/known axial spondyloarthritis (axSpA), focusing on enhancing diagnostic clarity and patient care through guidelines.

MATERIALS AND METHODS

A specialised task force was formed, comprising 7 radiologists, 11 rheumatologists from the Assessment of Spondyloarthritis International Society (ASAS) and a patient representative. Using the Delphi method, two rounds of surveys were conducted among ASAS members. These surveys aimed to identify critical elements for imaging referrals and to refine these elements for practical application. The task force deliberated on the survey outcomes and proposed a set of recommendations, which were then presented to the ASAS community for a decisive vote.

RESULTS

The collaborative effort resulted in a set of six detailed recommendations for clinicians involved in requesting imaging for patients with suspected or known axSpA. These recommendations cover crucial areas, including clinical features indicative of axSpA, clinical features, mechanical factors, past imaging data, potential contraindications for specific imaging modalities or contrast media and detailed reasons for the examination, including differential diagnoses. Garnering support from 73% of voting ASAS members, these recommendations represent a consensus on optimising imaging request protocols in axSpA.

CONCLUSION

The ASAS recommendations offer comprehensive guidance for rheumatologists in requesting imaging for axSpA, aiming to standardise requesting practices. By improving the precision and relevance of imaging requests, these guidelines should enhance the clinical impact of radiology reports, facilitate accurate diagnosis and consequently improve the management of patients with axSpA.

Axial Imaging in Spondyloarthritis

Imaging plays a crucial role in diagnosing and forecasting treatment outcomes in axial spondyloarthritis. Conventional radiography may overlook patients in the initial stages of the disease, while MRI is sensitive in identifying inflammation early on. Computed tomography reliably detects structural abnormalities. Practicing rheumatologists must possess a fundamental understanding of interpreting both active inflammatory and structural lesions in axial spondyloarthritis.

Imaging in Inflammatory Bowel Disease

The incidence of inflammatory bowel disease (IBD) is rising globally. We need more tools and techniques in our armamentarium for early diagnosis, tight monitoring, and to assess disease complications of IBD. This article reviews the role of cross-sectional imaging, mainly computed tomography, MRI, and intestinal ultrasound (IUS) in IBD and its advantages, disadvantages, and limitations. While popular in other parts of the world, IUS is underutilized in the United States. It is safe, accurate, can be repeated multiple times and provides quick and actionable results in IBD care without the risk of radiation and contrast.

Bone assessment of the sacroiliac joint in ankylosing spondylitis: Comparison between computed tomography and zero echo time MRI

PURPOSE

To demonstrate the clinical applicability of zero echo time magnetic resonance imaging (ZTE MRI) in bone assessment of the sacroiliac joint in ankylosing spondylitis.

METHOD

Between January 2021 and November 2021, twenty-one ankylosing spondylitis patients underwent clinically indicated MRI including ZTE sequence, in addition, all patients underwent a CT scan covering the sacroiliac joints within 6 months of the MRI examination. The sensitivity, specificity, and accuracy of ZTE MRI were calculated using CT as the reference standard. Cohen's κappa tests were applied to assess the agreement of positive imaging findings (including erosions, osteosclerosis, bony cystic changes, and joint space changes) between MRI and CT as well as the inter-reader agreement for the grading of sacroiliitis in AS patients.

RESULTS

There was no statistical significance between ZTE MRI and CT in detecting of ankylosing spondylitis(p＞0.05). The consistency of the diagnosis of positive imaging findings between ZTE MRI and CT was moderate to excellent (ranging from 0.611 to 0.889), and the consistency of the scores of positive imaging was good to excellent (ranging from 0.857 to 0.979).

CONCLUSIONS

ZTE MRI provides "CT-like" contrast for bony changes of the sacroiliac joint in ankylosing spondylitis and could simplify and reduce costs for some AS patients when both MRI and CT are typically required.

Bone marrow edema in children: chronic nonbacterial osteomyelitis and its mimickers

Bone marrow is a highly cellular tissue undergoing significant developmental and physiologic changes with age. Indeed, with maturation from pediatric to the adult age there is a progressive, centrifugal conversion from red to yellow bone marrow. Histological characteristics of bone marrow are reflected in MR image signal. MR is therefore extremely sensitive in detecting pathological changes which are mostly characterized by increased free water causing high signal intensity on T2. Among the numerous diseases causing bone marrow edema in children chronic nonbacterial osteomyelitis (CNO) certainly has to be mentioned. This idiopathic inflammatory disorder is characterized by nonspecific migrating symptoms like skeletal pain with phases of exacerbations and relapses with alternating acute and chronic MR signs and it is often a diagnosis of exclusion. Hence, with bone marrow edema, various features at imaging should be considered to differentiate malignancies such as osseous lymphoma, osteosarcoma, and Ewing's sarcoma as well as benign lesions like osteomyelitis, post-traumatic, or post-treatment bone marrow edema. The aim of this review is to recall the main characteristics of CNO and provide an overview of its main mimickers highlighting similarities and differences.

The role of sacro-iliac joint magnetic resonance imaging in the diagnosis of axial spondyloarthritis: focus on differential diagnosis in women

OBJECTIVE

To review the role of sacro-iliac magnetic resonance imaging (MRI) in the diagnosis of axial spondyloarthritis (AxSpA), with a focus on gender differences.

METHODS

The experience of the authors and the results of an informal literature review are reported.

RESULTS

Inflammatory changes of the sacro-iliac joint are the hallmark of AxSpA. Early, non-radiographic sacroiliitis may be diagnosed with MRI through the assessment of bone marrow edema (BMO) as well as concomitant structural damage. The MRI protocol should include three necessary sequences, i.e., fat-saturated T2-weighted sequences on two orthogonal planes, T1-weighted semi-coronal sequence, and fat-suppressed T1-weighted semi-coronal sequence. Inflammatory changes comprise required signs (BMO and/or osteitis) and additional signs, including synovitis (better defined as joint space enhancement), enthesitis, and capsulitis. Structural changes consist of erosions, sclerosis, fat metaplasia, and ankylosis. Due to mechanical axial strain, inflammatory changes in the sacro-iliac joint can be found in healthy individuals, runners, and patients with nonspecific low back pain. The prevalence of BMO is higher in women during pregnancy and postpartum, even 12 months after childbirth, but the extent and distribution of MRI findings may help in the differential diagnosis. Other challenges in the MRI diagnosis of sacroiliitis are subchondral T2 hyperintensity during developmental age, periarticular sclerosis in healthy subjects, or osteitis condensans ilii, and several pathological conditions that may mimic AxSpA, some of which are more frequently found in women.

CONCLUSIONS

The described diagnostic challenges impose a multidisciplinary approach combining imaging findings with clinical and laboratory data.

ESR Essentials: Imaging of sacroiliitis-practice recommendations by ESSR

Sacroiliitis is commonly seen in patients with axial spondyloarthritis, in whom timely diagnosis and treatment are crucial to prevent irreversible structural damage. Imaging has a prominent place in the diagnostic process and several new imaging techniques have been examined for this purpose. We present a summary of updated evidence-based practice recommendations for imaging of sacroiliitis. MRI remains the imaging modality of choice for patients with suspected sacroiliitis, using at least four sequences: coronal oblique T1-weighted and fluid-sensitive sequences, a perpendicular axial oblique sequence, and a sequence for optimal evaluation of the bone-cartilage interface. Both active inflammatory and structural lesions should be described in the report, indicating location and extent. Radiography and CT, especially low-dose CT, are reasonable alternatives when MRI is unavailable, as patients are often young. This is particularly true to evaluate structural lesions, at which CT excels. Dual-energy CT with virtual non-calcium images can be used to depict bone marrow edema. Knowledge of normal imaging features in children (e.g., flaring, blurring, or irregular appearance of the articular surface) is essential for interpreting sacroiliac joint MRI in children because these normal processes can simulate disease. CLINICAL RELEVANCE STATEMENT: Sacroiliitis is a potentially debilitating disease if not diagnosed and treated promptly, before structural damage to the sacroiliac joints occurs. Imaging has a prominent place in the diagnostic process. We present a summary of practice recommendations for imaging of sacroiliitis, including several new imaging techniques. KEY POINTS: • MRI is the modality of choice for suspected inflammatory sacroiliitis, including a joint-line-specific sequence for optimal evaluation of the bone-cartilage interface to improve detection of erosions. • Radiography and CT (especially low-dose CT) are reasonable alternatives when MRI is unavailable. • Knowledge of normal imaging features in children is mandatory for interpretation of MRI of pediatric sacroiliac joints.

How to Approach the Imaging Differential Diagnosis of Rheumatic Diseases by Anatomic Location

The purpose of this review is to present an approach to differential diagnosis based on the particular features of involvement of the most common rheumatological conditions focused on anatomic location (by joint). The most common radiological signs and how they are demonstrated in different modalities, as well as the typical patterns of involvement are analyzed, with the aim to facilitate the differential diagnosis. Early and adequate adjustment of treatment has an effect on outcome, and on this basis, early diagnosis and characterization are paramount to appropiately manage patients.

Whole-Body Magnetic Resonance Imaging in Rheumatology

This review focuses on the most frequent whole-body MRI applications in patients with rheumatological pathologies, for which this tool can be helpful to both radiologists and clinicians. It reports technical aspects of the acquisition of both 1.5 and 3.0 T scanners. The article lists the main findings that help radiologists during the evaluation of a specific pathology, both in the diagnostic phase and during follow-up.

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.

Advanced Imaging of Gout and Other Inflammatory Diseases Around the Knee

The knee is one of the most commonly affected joints in the course of inflammatory arthropathies, such as crystal-induced and autoimmune inflammatory arthritis. The latter group includes systemic connective tissue diseases and spondyloarthropathies. The different pathogenesis of these entities results in their varied radiologic images. Some lead quickly to joint destruction, others only after many years, and in the remaining, destruction will not be a distinguishing radiologic feature.Radiography, ultrasonography, and magnetic resonance imaging have traditionally been the primary modalities in the diagnosis of noninflammatory and inflammatory arthropathies. In the case of crystallopathies, dual-energy computed tomography has been introduced. Hybrid techniques also offer new diagnostic opportunities. In this article, we discuss the pathologic findings and imaging correlations for crystallopathies and inflammatory diseases of the knee, with an emphasis on recent advances in their imaging diagnosis.

Whole-body MRI for the investigation of joint involvement in inflammatory arthritis

OBJECTIVES

This study aimed to develop a novel whole-body MRI protocol capable of assessing inflammatory arthritis at an early stage in multiple joints in one examination.

MATERIALS AND METHODS

Forty-six patients with inflammatory joint symptoms and 9 healthy volunteers underwent whole-body MR imaging on a 3.0 T MRI scanner in this prospective study. Image quality and pathology in each joint, bursae, entheses and tendons were scored by two of three radiologists and compared to clinical joint scores. Participants were divided into three groups based on diagnosis at 1-year follow-up (healthy volunteers, rheumatoid arthritis and all other types of arthritis). Radiology scores were compared between the three groups using a Kruskal-Wallis test. The clinical utility of radiology scoring was compared to clinical scoring using ROC analysis.

RESULTS

A protocol capable of whole-body MR imaging of the joints with an image acquisition time under 20 min was developed with excellent image quality. Synovitis scores were significantly higher in patients who were diagnosed with rheumatoid arthritis at 12 months (p < 0.05). Radiology scoring of bursitis showed statistically significant differences between each of the three groups-healthy control, rheumatoid arthritis and non-rheumatoid arthritis (p < 0.05). There was no statistically significant difference in ROC analysis between MRI and clinical scores.

CONCLUSION

This study has developed a whole-body MRI joint imaging protocol that is clinically feasible and shows good differentiation of joint pathology between healthy controls, patients with rheumatoid arthritis and patients with other forms of arthritis.

Knowledge, Attitudes, and Practices of Moroccan Community Rheumatologists' Regarding the Management of Non-radiographic Axial Spondyloarthritis: A National Cross-Sectional Study

Introduction Non-radiographic axial spondyloarthritis (nr-axSpA) is within the spectrum of axial spondyloarthritis (axSpA). The emergence of the nr-axSpA concept, defined by the absence of significant erosive damage to the sacroiliac joints, has prompted numerous initiatives aimed at enhancing the early detection and management of this condition. The aim of the study was to assess the knowledge, attitudes, and practices related to the diagnosis and management of nr-axSpA by rheumatologists in Morocco. Methods We conducted a cross-sectional online survey among the rheumatologist community in Morocco. Rheumatologists received via e-mail a structured Google Forms (Google Inc., Mountainview, CA) questionnaire divided into four sections: sociodemographic data of rheumatologists, knowledge, attitudes, and practices related to the diagnosis and treatment management of nr-axSpA. Results A total of 110 rheumatologists (mean age of 44±13 years, 77.3% females, median professional experience of 12 years (4, 75; 26.25 years)) participated in the survey (response rate of 25%). Most responders reported a diagnosis delay issue in spondyloarthritis (SpA) (93.6%); 70.9% of rheumatologists incorrectly regarded the 2009 Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axSpA as diagnostic criteria. Rheumatologists' awareness of recommended magnetic resonance imaging (MRI) sequences for detecting sacroiliac joint inflammation and structural changes in SpA varied significantly, from 69.1% to 14.5%. Their knowledge of additional subchondral edema cases in these joints, beyond SpA, ranged from 48.2% to 87.3%. Almost all rheumatologists believed that the use of sacroiliac MRI would contribute to the early diagnosis of axSpA (97.3%) but could also lead to false positive diagnoses, according to 47.3% of rheumatologists; 73.6% believed that incorrectly using the 2009 ASAS classification criteria as diagnostic criteria in nr-axSpA could also result in false-positive diagnoses. In their practice, 2009 ASAS classification criteria were used as diagnostic criteria in axSpA by 39.1% of rheumatologists. Of the total participants, 91.8% indicated that they approach nr-axSpA similarly to radiographic axial spondyloarthritis, with disparities in recommendations of biological therapies. Conclusion Our survey provides insight into the current status of nr-axSpA management among Moroccan rheumatologists. It also addresses concerns regarding the risk of false positive diagnoses when using the 2009 ASAS classification criteria for axSpA as diagnostic criteria by rheumatologists and the potential risk of misdiagnosis associated with excessive reliance on MRI, despite its utility for early diagnosis.

The OMERACT whole-body MRI scoring system for inflammation in peripheral joints and entheses (WIPE) in spondyloarthritis - reference image atlas for the knee region

OBJECTIVE

To develop a reference image atlas for the Outcome Measures in Rheumatology whole-body MRI scoring system for inflammation in peripheral joints and entheses (OMERACT MRI-WIPE) of the knee region.

METHODS

Image examples of each pathology, location and grade, were collected and discussed at web-based, interactive meetings within the OMERACT MRI in Arthritis Working Group. Subsequently, reference images were selected by consensus.

RESULTS

Reference images for each grade, pathology and location are depicted, along with definitions, reader rules and recommended MRI-sequences.

CONCLUSION

The atlas guides scoring whole-body MRIs for inflammation in joints and entheses of the knee region according to MRI-WIPE methodology in clinical trials and cohorts.

A clinical perspective on imaging in juvenile idiopathic arthritis

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

Hip and pelvis region MRI reference image atlas for scoring inflammation in peripheral joints and entheses according to the OMERACT-MRI WIPE scoring system in patients with spondyloarthritis

OBJECTIVE

To develop a reference image atlas for scoring the hip/pelvis region according to the OMERACT whole-body MRI scoring system for inflammation in peripheral joints and entheses (MRI-WIPE).

METHODS

We collected image examples of each pathology, location and grade, discussed them at web-based, interactive meetings and, finally, selected reference images by consensus.

RESULTS

Reference images for each grade and location of osteitis, synovitis and soft tissue inflammation are provided, as are definitions, reader rules and recommended MRI-sequences.

CONCLUSION

A reference image atlas was created to guide scoring whole-body MRIs for arthritis and enthesitis in the hip/pelvis region in spondyloarthritis/psoriatic arthritis clinical trials and cohorts.

MRI of Temporomandibular Joint Disorders: A Comparative Study of 0.55 T and 1.5 T MRI

OBJECTIVES

Temporomandibular disorders (TMDs) are common and may cause persistent functional limitations and pain. Magnetic resonance imaging (MRI) at 1.5 and 3 T is commonly applied for the evaluation of the temporomandibular joint (TMJ). No evidence is available regarding the feasibility of modern low-field MRI for the assessment of TMDs. The objective of this prospective study was to evaluate the image quality (IQ) of 0.55 T MRI in direct comparison with 1.5 T MRI.

MATERIALS AND METHODS

Seventeen patients (34 TMJs) with suspected intraarticular TMDs were enrolled, and both 0.55 and 1.5 T MRI were performed on the same day. Two senior readers independently evaluated the IQ focusing on the conspicuity of disc morphology (DM), disc position (DP), and osseous joint morphology (OJM) for each joint. We analyzed the IQ and degree of artifacts using a 4-point Likert scale (LS) at both field strengths. A fully sufficient IQ was defined as an LS score of ≥3. Nonparametric Wilcoxon test for related samples was used for statistical comparison.

RESULTS

The median IQ for the DM and OJM at 0.55 T was inferior to that at 1.5 T (DM: 3 [interquartile range {IQR}, 3-4] vs 4 [IQR, 4-4]; OJM: 3 [IQR, 3-4] vs 4 [IQR 4-4]; each P < 0.001). For DP, the IQ was comparable (4 [IQR 3-4] vs 4 [IQR 4-4]; P > 0.05). A sufficient diagnostic IQ was maintained for the DM, DP, and OJM in 92% of the cases at 0.55 T and 100% at 1.5 T. Minor image artifacts (LS score of ≥3) were more prevalent at 0.55 T (29%) than at 1.5 T (12%).

CONCLUSIONS

Magnetic resonance imaging of the TMJ at 0.55 T yields a lower IQ than does MRI at 1.5 T but maintains sufficient diagnostic confidence in the majority of patients. Further improvements are needed for reliable clinical application.

The Role of Early Treatment in the Management of Axial Spondyloarthritis: Challenges and Opportunities

Axial spondyloarthritis (axSpA) is a chronic, inflammatory rheumatic disease that primarily affects the axial skeleton, often inflicting severe pain, diminished mobility, and a compromised quality of life. The advent of Assessment of SpondyloArthritis international Society (ASAS) classification criteria for spondyloarthritis (SpA) have enabled the classification of patients with axSpA in the non-radiographic stage but poorly perform if mistakenly used for diagnostic purposes. Despite notable progress in early diagnosis facilitated by referral strategies and extensive magnetic resonance imaging (MRI) utilization, diagnostic delays persist as a concerning issue. This underscores the urgency to narrow the diagnostic gap and highlights the critical role of early diagnosis in mitigating the long-term structural damage associated with this condition. Research into the impact of non-steroidal anti-inflammatory drugs (NSAIDs) and biologic disease-modifying antirheumatic drugs (bDMARDs) on inflammatory symptoms and radiographic progression has been extensive. A compelling body of evidence suggests that early intervention leads to superior disease outcomes. However, most of these studies have centered on patients with established diseases rather than those in the early stages. Consequently, findings from studies on early pharmacological intervention remain inconclusive, and the potential for modifying the disease trajectory is still debatable. Without precise data from clinical trials, insights from basic science regarding the pathogenic mechanisms might point toward potential targets that warrant early intervention in the disease process. This review underscores the urgency of early diagnosis and intervention in axSpA, highlighting ongoing research gaps and the need for further exploration to improve patient outcomes.

Advances in the Evaluation of Peripheral Enthesitis by Magnetic Resonance Imaging in Patients With Psoriatic Arthritis

Enthesitis is a key disease manifestation in patients with psoriatic arthritis (PsA) that considerably contributes to pain, lower physical function, and reduced quality of life. Clinical assessment of enthesitis lacks sensitivity and specificity, and therefore better methods are urgently needed. Magnetic resonance imaging (MRI) allows detailed assessment of the components of enthesitis, and consensus-based validated MRI scoring systems exist. These include the Outcome Measures in Rheumatology (OMERACT) Heel Enthesitis MRI Scoring System (HEMRIS) method, which assesses the entheses of the heel region in a detailed manner, and the OMERACT MRI Whole-Body Score for Inflammation in Peripheral Joints and Entheses (MRI-WIPE) method, which provides an overall assessment of the inflammatory burden in the peripheral entheses and joints in the entire body using whole-body MRI. At an MRI workshop at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 meeting in Brooklyn, the MRI appearances of peripheral enthesitis were described, as were the scoring methods. The utility of MRI for improved assessment of enthesitis was demonstrated with examples of patient cases. Clinical trials in PsA that evaluate enthesitis by MRI as a key endpoint should include the presence of MRI enthesitis as an inclusion criterion, and apply validated MRI outcomes to assess the effect of therapeutics on enthesitis are recommended.

Added value of high-resolution ultrasound and MRI in the evaluation of rheumatologic diseases

Rheumatologic diseases are a widespread group of disorders affecting the joints, bones, and connective tissue, and leading to significant disability. Imaging is an indispensable component in diagnosing, assessing, monitoring, and managing these disorders, providing information about the structural and functional alterations occurring within the affected joints and tissues. This review article aims to compare the utility, specific clinical applications, advantages, and limitations of high-resolution ultrasound and magnetic resonance imaging in the context of rheumatologic diseases. It also provides insights into the imaging features of various types of inflammatory arthritis with clinical relevance and a focus on high-resolution ultrasound and magnetic resonance imaging. By understanding the comparative aspects of high-resolution ultrasound and magnetic resonance imaging, it is easier for the treating physicians to make informed decisions when selecting the optimal imaging modality for specific diagnostic purposes, effective treatment planning, and improve patient outcomes. The patterns of soft tissue and joint involvement; bony erosion and synovitis help in differentiating between various type of arthritis. Involvement of various small joints of the hands also gives an insight into the type of arthritis. We also briefly discuss the potential applications of emerging techniques, such as ultrasound elastography, contrast-enhanced ultrasound, and dual-energy CT, in the field of rheumatology.

Magnetic resonance imaging in spondyloarthritis: Friend or Foe?

Magnetic resonance imaging (MRI) has emerged as a valuable tool for early detection and of axial spondyloarthritis (axSpA). A standardized imaging acquisition protocol, aligned with the current state-of-the-art, is crucial to obtain MRI scans that meet the diagnostic quality requirements. It is important to note that certain lesions, particularly bone marrow edema (BME), can be induced by mechanical stress or be a manifestation of another non-inflammatory disorder and may mimic the characteristic findings of axSpA on MRI. Therefore, a thorough assessment of MRI lesions, considering their localization and presence of highly specific features such as erosions and backfill, becomes imperative. Additionally, the application of additional imaging modalities, when necessary, can contribute to the differentiation of axSpA from other conditions that may exhibit similar MRI findings. This review provides recommendations on how to perform MRI in daily clinical practice and how to interpret finding from the differential diagnostic point of view.

MR-Imaging in Osteoarthritis: Current Standard of Practice and Future Outlook

Osteoarthritis (OA) is a common degenerative joint disease that affects millions of people worldwide. Magnetic resonance imaging (MRI) has emerged as a powerful tool for the evaluation and monitoring of OA due to its ability to visualize soft tissues and bone with high resolution. This review aims to provide an overview of the current state of MRI in OA, with a special focus on the knee, including protocol recommendations for clinical and research settings. Furthermore, new developments in the field of musculoskeletal MRI are highlighted in this review. These include compositional MRI techniques, such as T2 mapping and T1rho imaging, which can provide additional important information about the biochemical composition of cartilage and other joint tissues. In addition, this review discusses semiquantitative joint assessment based on MRI findings, which is a widely used method for evaluating OA severity and progression in the knee. We analyze the most common scoring methods and discuss potential benefits. Techniques to reduce acquisition times and the potential impact of deep learning in MR imaging for OA are also discussed, as these technological advances may impact clinical routine in the future.

Comparison between 2D FSE T2-weighted Dixon MRI and contrast-enhanced 2D FSE and 3D FSPGR T1-weighted Dixon MRI to quantify inflammation in hands of patients with early rheumatoid arthritis

PURPOSE

The purpose of this study was to compare two-dimensional (2D) T2-weighted, contrast-enhanced 2D T1-weighted and contrast-enhanced three-dimensional (3D) T1-weighted Dixon MRI sequences to assess disease activity using the RAMRIS scoring system in hands of patients with early rheumatoid arthritis.

MATERIALS AND METHODS

Twenty-five patients (19 women, 6 men; mean age 51.4 years ± 12.7 years [SD], age range: 28-70 years) with rheumatoid arthritis prospectively underwent MRI examination of both hands at 1.5 T using 2D fast spin-echo (FSE) T2-weighted, contrast-enhanced 2D FSE T1-weighted and contrast-enhanced 3D fast spoiled gradient echo (FSPGR) T1-weighted Dixon sequences. Three radiologists independently assessed disease activity according to RAMRIS using Dixon water-only and fat-only images. Intraclass correlation coefficients (ICC) were calculated to assess inter-technique and interobserver agreements.

RESULTS

Agreement to assess total RAMRIS score was very good between the MRI protocols (mean ICC ranging from 0.81 to 0.93) and between readers (mean ICC ranging from 0.91 to 0.94). Mean total RAMRIS scores of the three readers were significantly greater with contrast-enhanced 3D FSPGR T1-weighted (42.73 ± 29.39) than with contrast-enhanced 2D FSE T1-weighted (35.81 ± 25.48) and 2D FSE T2-weighted (32.20 ± 25.06) Dixon sequences.

CONCLUSION

2D FSE T2-weighted, contrast-enhanced 2D FSE T1-weighted Dixon and contrast-enhanced 3D FSPGR T1-weighted Dixon protocols are reproducible alternatives for the RAMRIS scoring in hands of patients with early rheumatoid arthritis. Coupling contrast-enhanced 3D FSPGR T1-weighted and 2D FSE T2-weighted sequences might be the most efficient option to completely assess the rheumatoid arthritis -related synovial and bone changes with the Dixon method.

Towards a simplified fluid-sensitive MRI protocol in small joints of the hand in early arthritis patients: reliability between modified Dixon and regular Gadolinium enhanced TSE fat saturated MRI-sequences

OBJECTIVE

MRI of small joints plays an important role in the early detection and early treatment of rheumatoid arthritis. Despite its sensitivity to demonstrate inflammation, clinical use is hampered by accessibility, long scan time, intravenous contrast, and consequent high costs. To improve the feasibility of MRI implementation in clinical practice, we introduce a modified Dixon sequence, which does not require contrast and reduces total acquisition time to 6 min. Because the reliability in relation to conventional MRI sequences is unknown, we determined this.

METHODS

In 29 consecutive early arthritis patients, coronal and axial T2-weighted modified Dixon acquisitions on 3.0 T MRI scanner were acquired from metacarpophalangeal 2-5 to the wrist, followed by the standard contrast-enhanced protocol on 1.5 T extremity MRI. Two readers scored osteitis, synovitis and tenosynovitis (summed as total MRI-inflammation), and erosions (all summed as total Rheumatoid Arthritis MRI Score (RAMRIS)). Intraclass correlation coefficients (ICCs) between readers, and comparing the two sequences, were studied. Spearman correlations were determined.

RESULTS

Performance between readers was good/excellent. Comparing modified Dixon and conventional sequences revealed good/excellent reliability: ICC for total MRI-inflammation score was 0.84 (95% CI:0.70-0.92), for erosions 0.90 (95% CI:0.79-0.96), and for the total RAMRIS score 0.88 (95% CI:0.77-0.94). The scores of total MRI-inflammation, total erosions, and total RAMRIS were highly correlated (ρ = 0.80, ρ = 0.81, ρ = 0.82, respectively).

CONCLUSION

The modified Dixon protocol is reliable compared to the conventional MRI protocol, suggesting it is accurate to detect MRI inflammation. The good correlation may be the first step towards a patient-friendly, short and affordable MRI protocol, which can facilitate the implementation of MRI for early detection of inflammation in rheumatology practice.

An Atypical Presentation of Seronegative Rheumatoid Arthritis

The American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 1987 classification for rheumatoid arthritis (RA) focuses on four main clinical findings without emphasizing biomarker serology. On the other hand, the updated ACR/EULAR 2010 classification relies more on acute-phase reactants and biomarker serology. While a positive rheumatoid factor (RF) and positive anti-citrullinated protein antibody (ACPA) are specific for RA, at least 15%-25% of patients are seronegative. Given that the ACR/EULAR 2010 classification is more likely to miss these seronegative patients, clinical judgment is important while assessing patients to avoid delays in diagnosis and onset of treatment.

Axial Skeleton Bone Marrow Changes in Inflammatory Rheumatologic Disorders

Magnetic resonance imaging (MRI) of the axial skeleton, spine, and sacroiliac (SI) joints is critical for the early detection and follow-up of inflammatory rheumatologic disorders such as axial spondyloarthritis, rheumatoid arthritis, and SAPHO/CRMO (synovitis, acne, pustulosis, hyperostosis, and osteitis/chronic recurrent multifocal osteomyelitis). To offer a valuable report to the referring physician, disease-specific knowledge is essential. Certain MRI parameters can help the radiologist provide an early diagnosis and lead to effective treatment. Awareness of these hallmarks may help avoid misdiagnosis and unnecessary biopsies. A bone marrow edema-like signal plays an important role in reports but is not disease specific. Age, sex, and history should be considered in interpreting MRI to prevent overdiagnosis of rheumatologic disease. Differential diagnoses-degenerative disk disease, infection, and crystal arthropathy-are addressed here. Whole-body MRI may be helpful in diagnosing SAPHO/CRMO.

Challenges in non-radiographic axial spondyloarthritis

Non-radiographic axial spondyloarthritis (nr-axSpA) is part of the spectrum or continuum of axSpA and is characterized by the absence of definite structural damage in the sacroiliac joints. The introduction of the concept of axSpA with two - non-radiographic and radiographic - stages stimulated activities related to the improvement of early diagnosis and treatment of this disease, but also opened a number of controversial topics in the field. In this article, we are discussing several challenges related to the concept of nr-axSpA, the diagnosis, and the treatment in the historical context and in the light of the recent data.

Implementation of the OMERACT Psoriatic Arthritis Magnetic Resonance Imaging Scoring System in a randomized phase IIb study of abatacept in psoriatic arthritis

OBJECTIVES

To investigate if the OMERACT PsA MRI Scoring System (PsAMRIS), including a novel total inflammation score, shows sensitivity to change with an agent (abatacept) known to impact clinical outcomes in PsA.

METHODS

We performed a post hoc analysis of a randomized phase IIb study of abatacept in patients with PsA and inadequate DMARD response. Participants received one of three abatacept dosing regimens [ABA3, ABA10 or ABA30/10 mg/kg (30 mg/kg switched to 10 mg/kg after two doses)] or placebo until day 169, then ABA10 through day 365. MRIs at baseline and days 85, 169 and 365 were centrally evaluated by two readers blinded to chronological order and treatment arm. Synovitis, osteitis, tenosynovitis, periarticular inflammation, bone erosions, joint space narrowing and bone proliferation were assessed using the PsAMRIS. A novel total inflammation score was tested.

RESULTS

MRIs for 123 patients were included. On day 169, ABA10 and ABA30/10 significantly reduced MRI synovitis and tenosynovitis, respectively, vs placebo [differences -0.966 (P = 0.039) and -1.652 (P = 0.014), respectively]. Synovitis in the placebo group increased non-significantly from baseline to day 169, total inflammation and tenosynovitis decreased non-significantly and all measures improved significantly after a switch to ABA10 [-1.019, -0.940, -2.275 (P < 0.05), respectively, day 365 vs day 169]. Structural outcomes changed minimally across groups.

CONCLUSION

Adults with PsA receiving ABA10 and ABA30/10 demonstrated significant resolution of inflammatory components of disease, confirmed by MRI, with synovitis and tenosynovitis improvements consistent with previously reported clinical responses for these doses. Results indicate that a reduction in OMERACT PsAMRIS inflammation scores may provide proof of tissue-level efficacy in PsA clinical trials.

REGISTRATION

ClinicalTrials.gov (https://clinicaltrials.gov), NCT00534313.

Diagnostic evaluation of the sacroiliac joints for axial spondyloarthritis: should MRI replace radiography?

The possibility of detection of structural damage on magnetic resonance imaging (MRI) of sacroiliac joints raises the question of whether MRI can substitute radiographs for diagnostic evaluation and to a further extent for classification of axial spondyloarthritis (axSpA). In this viewpoint, we will argue that it is time to replace conventional radiographs with MRI for the assessment of structural changes in sacroiliac joints. This message is based on current data on the following questions: (1) How reliable are conventional radiographs in the diagnosis of axSpA overall and radiographic axSpA in particular? (2) How does T1-weighted MRI compare to radiographs in the detection of sacroiliitis? (3) Are there now other (better) MRI sequences than T1-weighted, which might be more suitable for the detection of structural lesions? (4) Which MRI sequences should be performed for the diagnostic evaluation of the sacroiliac joints? (5) Do we have data to define sacroiliitis based on structural changes detected by MRI?

TOFA-PREDICT study protocol: a stratification trial to determine key immunological factors predicting tofacitinib efficacy and drug-free remission in psoriatic arthritis (PsA)

INTRODUCTION

Psoriatic arthritis (PsA) is a chronic, inflammatory, musculoskeletal disease that affects up to 30% of patients with psoriasis. Current challenges in clinical care and research include personalised treatment, understanding the divergence of therapy response and unravelling the multifactorial pathophysiology of this complex disease. Moreover, there is an urgent clinical need to predict, assess and understand the cellular and molecular pathways underlying the response to disease-modifying antirheumatic drugs (DMARDs). The TOFA-PREDICT clinical trial addresses this need. Our primary objective is to determine key immunological factors predicting tofacitinib efficacy and drug-free remission in PsA.

METHODS AND ANALYSIS

In this investigator-initiated, phase III, multicentre, open-label, four-arm randomised controlled trial, we plan to integrate clinical, molecular and imaging parameters of 160 patients with PsA. DMARD-naïve patients are randomised to methotrexate or tofacitinib. Additionally, patients who are non-responsive to conventional synthetic (cs)DMARDs continue their current csDMARD and are randomised to etanercept or tofacitinib. This results in four arms each with 40 patients. Patients are followed for 1 year. Treatment response is defined as minimal disease activity at week 16. Clinical data, biosamples and images are collected at baseline, 4 weeks and 16 weeks; at treatment failure (treatment switch) and 52 weeks. For the first 80 patients, we will use a systems medicine approach to assess multiomics biomarkers and develop a prediction model for treatment response. Subsequently, data from the second 80 patients will be used for validation.

ETHICS AND DISSEMINATION

The study was approved by the Medical Research Ethics Committee in Utrecht, Netherlands, is registered in the European Clinical Trials Database and is carried out in accordance with the Declaration of Helsinki. The study's progress is monitored by Julius Clinical, a science-driven contract research organisation.

TRIAL REGISTRATION NUMBER

EudraCT: 2017-003900-28.

Comparison of High-Resolution Ultrasonography With Magnetic Resonance Imaging in Rheumatoid Arthritis

Objective:

The aim of this study was to examine whether high-resolution ultrasonography (HRUS) can provide information, on signs of inflammation and destruction, due to rheumatoid arthritis (RA). The focus was on the wrist joint, during early and late disease and compared the findings to those with magnetic resonance imaging (MRI).

Materials and Methods:

The study was based on 31 RA patients, with joint involvements, who were selected from those attending the outpatient rheumatology clinic. The patients completed both HRUS and MRI examinations, and their results were compared.

Results:

The HRUS and MRI images had near-perfect agreement, for detecting joint anomalies, in those RA patients. While comparing the overall performance of the HRUS and MRI studies, it was observed that HRUS was equal or nearly equal, demonstrating 90.83%, 100.0% and 94.93%, diagnostic sensitivity, specificity, and accuracy, respectively, for diagnosing RA pathologies.

Conclusion:

The early diagnosis of RA with HRUS and MRI examinations is very important, in the early treatment of RA. The HRUS examinations demonstrated a sensitive and reliable diagnostic method for assessing inflammatory activity and destructive changes in the joints of these RA patients, with HRUS findings comparable to those of MRI.

To Contrast or Not to Contrast? On the Role of Contrast Enhancement in Hand MRI Studies of Patients with Rheumatoid Arthritis

Currently, clinical indications for the application of gadolinium-based contrast agents (GBCA) in magnetic resonance imaging (MRI) are increasingly being questioned. Consequently, this study aimed to evaluate the additional diagnostic value of contrast enhancement in MRI of the hand in patients with rheumatoid arthritis (RA). Thirty-one patients with RA (mean age, 50 ± 14 years (range, 18–72 years)) underwent morphologic MRI scans on a clinical 3 T scanner. MRI studies were analyzed based on (1) the Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) and (2) the GBCA-free RAMRIS version, termed RAMRIS Sine-Gadolinium-For-Experts (RAMRIS-SAFE), in which synovitis and tenosynovitis were assessed using the short-tau inversion-recovery sequence instead of the post-contrast T1-weighted sequence. The synovitis subscores in terms of Spearman’s ρ, as based on RAMRIS and RAMRIS-SAFE, were almost perfect (ρ = 0.937; p < 0.001), while the tenosynovitis subscores were less strongly correlated (ρ = 0.380 p = 0.035). Correlation between the total RAMRIS and RAMRIS-SAFE was also almost perfect (ρ = 0.976; p < 0.001). Inter-rater reliability in terms of Cohen’s κ was high (0.963 ≤ κ ≤ 0.925). In conclusion, RAMRIS-SAFE as the GBCA-free version of the well-established RAMRIS is a patient-friendly and resource-efficient alternative for assessing disease-related joint changes in RA. As patients with RA are subject to repetitive GBCA applications, non-contrast imaging protocols should be considered.

Ankle Magnetic Resonance Imaging in Juvenile Idiopathic Arthritis Versus Non-Juvenile Idiopathic Arthritis Patients with Arthralgia

This retrospective case–control study aimed to evaluate whether Magnetic Resonance Imaging (MRI) enables differentiation of ankle arthritis in Juvenile Idiopathic Afrthritis JIA from ankle arthralgia of unknown aetiology in patients clinically suspected of JIA. Forty-four children, at ages 5–16, who underwent MRI of the ankle from January 2016 to March 2021 for clinically suspected active ankle arthritis in the course of JIA were included. MRI findings in both groups—patients with the final diagnosis of JIA and without final diagnosis of JIA—were compared and scored. The sum of the scores of 22 ankle lesions in an individual patient (active, destructive and developmental), so-called the MRI summarized score, was calculated and tested in terms of the most optimal diagnosis of JIA. Interobserver agreement was calculated. Inflammatory features were seen on MRI in 38 out of all the included patients (86%). The most common lesions in both groups were effusion in the tibio-talar joint (68% in JIA and 64% in the arthralgia group) and effusion in subtalar joint (64% in JIA vs. 59% in the arthralgia group). In general, more lesions were identified in the JIA group than in non-JIA. However, only tenosynovitis was significantly more common in the JIA vs. non-JIA group (p = 0.031). The MRI summarized score did not allow for discrimination between ankle arthritis in JIA from non-JIA patients; the best levels of sensitivity (32%), specificity (91%), positive predictive value PPV (78%) and negative predictive value NPV (57%) were achieved only at the cut-off point of 10.

MRI in axial spondyloarthritis: understanding an 'ASAS-positive MRI' and the ASAS classification criteria

In 2009, the Assessment of SpondyloArthritis international Society (ASAS) published a definition of 'active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis'. This new definition of an 'ASAS-positive MRI' was integral to new classification criteria for axial spondyloarthritis that were published in the same year. The ASAS MRI definition had the considerable advantage of simplicity and the definition gained popularity as guidance for interpreting MRI of the sacroiliac joints in clinical practice. However, classification criteria are not designed for use in clinical practice with the consequence that overreliance on the presence of bone marrow edema, which is the principal determinant of an 'ASAS-positive MRI', may result in a tendency to overcall inflammatory sacroiliitis in the clinical setting. This article aims to inform the reader about the rationale behind the ASAS definition of a positive MRI and ASAS classification criteria, their proper use in research and why they should not be used in clinical practice. The article also contains guidance for an updated imaging protocol and interpretation of images including typical imaging findings, differential diagnosis, and common pitfalls.

Imaging of cervical spine involvement in inflammatory arthropathies: a review

The cervical spine can be affected by many types of inflammatory arthropathies, and the most common autoimmune diseases with cervical spine involvement are rheumatoid arthritis (RA), spondyloarthritis (SpA), and juvenile idiopathic arthritis (JIA). The clinical symptoms of cervical spine pathologies are often nonspecific or absent; therefore, imaging plays a crucial diagnostic role. RA is the most prevalent autoimmune disease; it often leads to cervical spine instability and subsequent myelopathy. In SpA, due to new bone formation, the characteristic lesions include syndesmophytes, parasyndesmophytes, and bone ankylosis, but instabilities are rare. In JIA, early apophyseal bone ankylosis is characteristic, in addition to impaired spinal growth. The aim of this review article is to discuss the imaging pathologies found in patients with RA, SpA, and JIA in the early and advanced stages. This knowledge would be helpful in the proper diagnosis and treatment of these diseases.

MRI Findings in Hip in Juvenile Idiopathic Arthritis

The aim of this study was to evaluate if magnetic resonance imaging allows hip arthritis in JIA to be differentiated from hip arthralgia of unknown etiology in juveniles clinically suspected for hip arthritis. This was a retrospective observational study which included 97 children with clinically suspected hip arthritis. Each hip was assessed and scored in MRI for signs of active and destructive inflammatory lesions and developmental lesions. MRI findings between JIA-confirmed patients and without final diagnosis of JIA were compared and the MRI summarized score was calculated, as the sum of scorings of all 24 hip lesions in an individual patient (i.a., effusion, synovitis, bone marrow edema, enthesitis). MRI showed at least one lesion in the majority of patients (95 patients; 98%). Effusion was the most common feature, followed by bone marrow oedema and synovitis. All lesions were more common in patients with a final diagnosis of JIA, especially synovitis and enthesitis (p = 0.037 and p = 0.047). The MRI summarized score was significantly higher in the JIA group than the non-JIA group: 3 (2–5) vs. 2 (2–2), respectively, p = 0.002. Using a cut-off score of 6, the MRI summarized score showed 25% sensitivity and 100% specificity indicating a good ability in discriminating hip arthritis during JIA from non-JIA patients. MRI allows hip arthritis in JIA to be differentiated from hip arthralgia of unknown etiology with good specificity, thus, may be helpful in confirming the diagnosis of JIA.

Imaging in Axial Spondyloarthritis: What is Relevant for Diagnosis in Daily Practice?

PURPOSE OF REVIEW

To explore how imaging may assist diagnosing axial spondyloarthritis in rheumatology practice.

RECENT FINDINGS

A diagnosis of axial spondyloarthritis is based on pattern recognition by synthesizing clinical, laboratory, and imaging findings. In health care settings providing low threshold access to advanced imaging, sacroiliac joint MRI is the preferred imaging modality in clinically suspected axial spondyloarthritis. In daily routine, the optimum protocol to assess suspected inflammatory back pain combines sacroiliac joint and spine MRI fitting a 30-min slot. Contextual assessment of concomitant structural and active MRI lesions is key to enhance diagnostic utility. In women with postpartum back pain suggestive of axial spondyloarthritis, recent reports advocate waiting 6-12 months after delivery before acquiring sacroiliac joint MRI. Major unmet needs are consistent MRI protocols, standardized training modules on how to evaluate axial MRI, and timely dissemination of imaging advances into mainstream practice both in rheumatology and in radiology. In rheumatology practice, MRI has become indispensable to help diagnose early axial spondyloarthritis. However, major gaps in training and knowledge transfer to daily care need to be closed.

Topography of Bone Erosions at the Metatarsophalangeal Joints in Rheumatoid Arthritis: Bilateral Mapping by Computed Tomography

OBJECTIVES

To describe the bilateral anatomical location of bone erosions (BE) at the metatarsophalangeal joints in patients with rheumatoid arthritis using computed tomography.

MATERIALS AND METHODS

Eighteen consecutive patients with established rheumatoid arthritis prospectively underwent computed tomography of both forefeet. Each joint surface of the metatarsal heads (MTH) and the proximal phalangeal bases were divided into four quadrants: superior, plantar, tibial, and fibular. The number of BE was cumulatively counted per patient, side, joint, per joint surface, and quadrant. Descriptive statistics, paired and unpaired samples t-tests, Pearson's correlation coefficients, ANOVA 2, and variance component analysis were performed.

RESULTS

There were 288 BE at the MTH and 66 at the proximal phalanges. The number of BE in one forefoot was a poor predictor of the absolute number of BE on the contralateral foot "r=0.54" and was unrelated to symptoms. The superior quadrants were less frequently affected than other quadrants for both the MTH "p<0.0001" and proximal phalanges "p<0.001." The tibial quadrant showed a higher number of BE compared to all other quadrants for MTH "p<0.03," proximal phalanges "p<0.01, and for the metatarsophalangeal joint as a whole "p<0.0001." Plantar and fibular quadrants were equally affected "p<0.05."

CONCLUSION

BE were found more frequently on the tibial side of the MTH in patients with rheumatoid arthritis.

Musculoskeletal Imaging for Dermatologists: Techniques in the Diagnosis and Management of Psoriatic Arthritis

Psoriatic arthritis is an inflammatory condition affecting up to 30% of patients with psoriasis. Patients may experience irreversible joint damage if not treated early, and diagnostic delays of even 6 months are associated with radiographic progression and impaired function. Therefore, early detection and intervention are of critical importance in patients with psoriatic arthritis. Given that psoriasis often precedes symptoms of psoriatic arthritis, dermatologists are uniquely positioned to identify patients with psoriatic arthritis early in their disease course, before permanent damage has occurred. Several screening tools have been developed to help dermatologists identify patients who may have psoriatic arthritis, but these tools may not capture patients with subclinical disease or quantify the type and severity of the underlying tissue insult, which is often the presenting sign of psoriatic arthritis. In these cases, a combination of clinical assessment and musculoskeletal imaging (e.g., ultrasound) is required. This review summarizes three common musculoskeletal imaging techniques used in the diagnosis and management of patients with psoriatic arthritis: conventional radiography, ultrasound, and magnetic resonance imaging. Further understanding of musculoskeletal imaging will assist dermatologists in making treatment decisions and allow them to have a more active role in the detection of psoriatic arthritis.