Tenosynovitis of the flexor tendons of the hand detected by MRI: an early indicator of rheumatoid arthritis

Quantification of joint mobility limitation in adult type 1 diabetes

Aims

Diabetic cheiroarthropathies limit hand mobility due to fibrosis and could be markers of a global profibrotic trajectory. Heterogeneity in definitions and lack of a method to measure it complicate studying associations with organ involvement and treatment outcomes. We measured metacarpophalangeal (MCP) joint extension as a metric and describe magnetic resonance (MR) imaging determinants of MCP restriction.

Methods

Adults with type 1 diabetes were screened for hand manifestations using a symptom questionnaire, clinical examination, and function [Duruoz hand index (DHI) and grip strength]. Patients were segregated by mean MCP extension (<20°, 20°-40°, 40°-60°, and >60°) for MR imaging (MRI) scanning. Patients in the four groups were compared using ANOVA for clinical features and MRI tissue measurements (tenosynovial, skin, and fascia thickness). We performed multiple linear regression for determinants of MCP extension.

Results

Of the 237 patients (90 men), 79 (33.8%) with cheiroarthropathy had MCP extension limitation (39° versus 61°, p < 0.01). Groups with limited MCP extension had higher DHI (1.9 vs. 0.2) but few (7%) had pain. Height, systolic blood pressure, and nephropathy were associated with mean MCP extension. Hand MRI (n = 61) showed flexor tenosynovitis in four patients and median neuritis in one patient. Groups with MCP mobility restriction had the thickest palmar skin; tendon thickness or median nerve area did not differ. Only mean palmar skin thickness was associated with MCP extension angle on multiple linear regression.

Conclusion

Joint mobility limitation was quantified by restricted mean MCP extension and had structural correlates on MRI. These can serve as quantitative measures for future associative and interventional studies.

Interosseous tendon inflammation in the hands of patients with clinically suspect arthralgia: analysis of MRI data from a prospective cohort study

BACKGROUND

Inflammation around the tendons of interosseous muscles of the hand (interosseous tendon inflammation) was recently observed with MRI for the first time in patients with rheumatoid arthritis and in at-risk individuals with detectable anti-citrullinated protein antibodies, generating the hypothesis that interosseous tendon inflammation precedes clinical arthritis. To better understand the role of interosseous tendon inflammation during the development of rheumatoid arthritis, we studied the frequency of interosseous tendon inflammation in healthy individuals and in those with arthralgia that was suspected of progressing to rheumatoid arthritis (ie, clinically suspect arthralgia) and the association of interosseous tendon inflammation with other symptoms of inflamed joint tissues and with clinical arthritis development.

METHODS

Adult (age ≥18 years) patients who presented with clinically suspect arthralgia and symptom-free (control) individuals underwent contrast-enhanced hand MRI. MRIs were evaluated for interosseous tendon inflammation on the radial and ulnar sides of the second to fifth metacarpophalangeal joints, and for synovitis, tenosynovitis, and osteitis using the rheumatoid arthritis MRI scoring system. Patients with clinically suspect arthralgia were followed up for clinical arthritis development. The presence of local tenosynovium was examined using immunohistochemistry for anti-CD55 and anti-CD68 on tissue from the hands of three embalmed bodies donated for scientific research. The primary outcome for the cross-sectional part of the study was the presence of interosseous tendon inflammation on MRI. The primary outcome for the longitudinal part of the study was development of clinical arthritis.

FINDINGS

Between April 3, 2012, and May 20, 2020, 667 patients with clinically suspect arthralgia (mean age 44 years [SD 13], 504 [76%] were women and 163 [24%] were men) underwent contrast-enhanced hand MRI. Between Nov 1, 2013, and Nov 30, 2014, 193 symptom-free controls were recruited (mean age 50 years [SD 16], 136 [70%] were women and 57 [30%] were men). Two (1%) of 193 symptom-free controls had interosseous tendon inflammation. Immunohistochemistry of cadaveric hand tissues showed no tenosynovium surrounding interosseous tendons. At inclusion, 67 (10%) of 667 patients with clinically suspect arthralgia had interosseous tendon inflammation (p<0·0001 vs symptom-free controls). Interosseous tendon inflammation occurred more frequently if synovitis (odds ratio [OR] 2·2 [95% CI 1·2-4·2]), or tenosynovitis (OR 9·7 [5·5-17·0]), was present at metacarpophalangeal joints. A three-dimensional MRI reconstruction suggested confluency of interosseous tendon inflammation with metacarpophalangeal-flexor-tenosynovitis. 91 (16%) of 558 patients with clinically suspect arthralgia developed clinical arthritis during follow-up (median total follow-up 25·3 months [95% CI 25·1-25·5]). Patients with clinically suspect arthralgia with interosseous tendon inflammation had a higher risk of developing clinical arthritis (hazard ratio [HR] 4·5 [2·8-7·2]), which was attenuated but still significant after adjusting for concomitant synovitis, tenosynovitis, or osteitis (HR 1·7 [1·02-2·8]).

INTERPRETATION

Interosseous tendon inflammation is almost absent in symptom-free individuals but occurs in people with clinically suspect arthralgia, in whom it correlates with symptoms and is associated with the development of clinical arthritis. The absence of local tenosynovium suggests that interosseous tendon inflammation arises from expanding local subclinical inflammation in the pre-arthritis phase of rheumatoid arthritis.

FUNDING

European Research Council and the Dutch Arthritis Society.

Synthetic Inflammation Imaging with PatchGAN Deep Learning Networks

Background: Gadolinium (Gd)-enhanced Magnetic Resonance Imaging (MRI) is crucial in several applications, including oncology, cardiac imaging, and musculoskeletal inflammatory imaging. One use case is rheumatoid arthritis (RA), a widespread autoimmune condition for which Gd MRI is crucial in imaging synovial joint inflammation, but Gd administration has well-documented safety concerns. As such, algorithms that could synthetically generate post-contrast peripheral joint MR images from non-contrast MR sequences would have immense clinical utility. Moreover, while such algorithms have been investigated for other anatomies, they are largely unexplored for musculoskeletal applications such as RA, and efforts to understand trained models and improve trust in their predictions have been limited in medical imaging. Methods: A dataset of 27 RA patients was used to train algorithms that synthetically generated post-Gd IDEAL wrist coronal T₁-weighted scans from pre-contrast scans. UNets and PatchGANs were trained, leveraging an anomaly-weighted L₁ loss and global generative adversarial network (GAN) loss for the PatchGAN. Occlusion and uncertainty maps were also generated to understand model performance. Results: UNet synthetic post-contrast images exhibited stronger normalized root mean square error (nRMSE) than PatchGAN in full volumes and the wrist, but PatchGAN outperformed UNet in synovial joints (UNet nRMSEs: volume = 6.29 ± 0.88, wrist = 4.36 ± 0.60, synovial = 26.18 ± 7.45; PatchGAN nRMSEs: volume = 6.72 ± 0.81, wrist = 6.07 ± 1.22, synovial = 23.14 ± 7.37; n = 7). Occlusion maps showed that synovial joints made substantial contributions to PatchGAN and UNet predictions, while uncertainty maps showed that PatchGAN predictions were more confident within those joints. Conclusions: Both pipelines showed promising performance in synthesizing post-contrast images, but PatchGAN performance was stronger and more confident within synovial joints, where an algorithm like this would have maximal clinical utility. Image synthesis approaches are therefore promising for RA and synthetic inflammatory imaging.

The value of ultrasound-defined tenosynovitis and synovitis in the prediction of persistent arthritis

OBJECTIVES

The value of US-defined tenosynovitis in predicting the persistence of inflammatory arthritis is not well described. In particular, the predictive utility of US-defined tenosynovitis of larger tendons is yet to be reported. We assessed the value of US-defined tenosynovitis alongside US-defined synovitis and clinical and serological variables in predicting persistent arthritis in an inception cohort of DMARD-naïve patients with early arthritis.

METHODS

One hundred and fifty DMARD-naïve patients with clinically apparent synovitis of one or more joints and a symptom duration of ≤3 months underwent baseline clinical, laboratory and US (of 19 bilateral joints and 16 bilateral tendon compartments) assessments. Outcomes were classified as persistent or resolving arthritis after 18 months' follow-up. The predictive value of US-defined tenosynovitis for persistent arthritis was compared with those of US-defined synovitis, and clinical and serological variables.

RESULTS

At 18 months, 99 patients (66%) had developed persistent arthritis and 51 patients (34%) had resolving disease. Multivariate logistic regression analysis showed that US-detected digit flexor tenosynovitis [odds ratio (OR): 6.6, 95% CI: 2.0 , 22.1, P = 0.002] provided independent predictive data for persistence over and above the presence of US-detected joint synovitis and RF antibodies. In the RF/ACPA-negative subcohort, US-defined digit flexor tenosynovitis remained a significant predictive variable (OR: 4.7, 95% CI: 1.4, 15.8, P = 0.012), even after adjusting for US-defined joint synovitis.

CONCLUSION

US-defined tenosynovitis provided independent predictive data for the development of persistent arthritis. The predictive role of US-defined digit flexor tenosynovitis should be further assessed; investigators should consider including this tendon site as a candidate variable when designing imaging-based predictive algorithms for persistent inflammatory arthritis development.

Intermetatarsal Bursitis, a Novel Feature of Juxtaarticular Inflammation in Early Rheumatoid Arthritis Related to Clinical Signs: Results of a Longitudinal Magnetic Resonance Imaging Study

OBJECTIVE

Intermetatarsal bursae in the forefeet possess a synovial lining similar to joints and tendon sheaths. Inflammation of these bursae (intermetatarsal bursitis [IMB]) was recently identified as specific for early rheumatoid arthritis (RA). The present study was undertaken to determine if IMB is indeed an RA feature by assessing the following: 1) the association with other local inflammatory measures (synovitis, tenosynovitis, and osteitis), 2) the association with clinical signs, and 3) whether it responds to disease-modifying antirheumatic drug (DMARD) therapy similarly to other local inflammatory measures.

METHODS

One hundred fifty-seven consecutive early RA patients underwent unilateral contrast-enhanced 1.5T forefoot magnetic resonance imaging (MRI) at diagnosis. MRIs were evaluated for IMB presence and for synovitis, tenosynovitis, and osteitis in line with the RA MRI Scoring (RAMRIS) system (summed as RAMRIS inflammation). MRIs at 4, 12, and 24 months were evaluated for IMB presence and size in patients who had IMB at baseline and received early DMARD therapy. Logistic regression and generalized estimating equations were used. Anti-citrullinated protein antibody (ACPA) stratification was performed.

RESULTS

Sixty-nine percent of RA patients had ≥1 IMB. In multivariable analysis on bursa level, presence of IMB was independently associated with local presence of synovitis and tenosynovitis, with odds ratios (OR) of 1.69 (95% confidence interval [95% CI] 1.12, 2.57) and 2.83 (95% CI 1.80, 4.44), respectively, but not osteitis. On the patient level, IMB presence was most strongly associated with tenosynovitis (OR 2.92 [95% CI 1.62, 5.24]). IMB presence was associated with local joint swelling (OR 2.7 [95% CI 1.3, 5.3]) and tenderness (OR 1.7 [95% CI 1.04, 2.9]) independent of RAMRIS inflammation. During treatment, IMB size decreased between 0 and 12 months. This decrease associated with decrease in RAMRIS inflammation, which was driven by synovitis decrease. Within ACPA-positive and ACPA-negative RA, similar results were obtained.

CONCLUSION

IMB particularly accompanies inflammation of the synovial lining of joints and tendon sheaths, showed a similar treatment response after DMARD initiation, and associates with typical clinical signs. These findings suggest that IMB represents a frequently present novel RA feature of juxtaarticular synovial inflammation.

Tendons and Tendon Sheaths of the Hand - An Update on MRI

BACKGROUND

 The tendons of the hand run in close proximity to each other and within retinacular tunnels adjacent to articular joints, while forming intersections in characteristic locations. The enclosing tendon sheaths are often sites of systemic or infectious inflammation.

METHOD

 This review article outlines the different entities of tendon and tendon sheath pathology and their manifestation in the hands. Diagnostic findings in tendon and tendon sheath disorders are illustrated using MRI imaging and discussed in context with the current literature.

RESULTS AND CONCLUSION

 Overuse may cause stenosis in the fibrous outer layer of the retinacula and the A1 annular ligaments as well as tendinosis. In contrast, proliferative tenosynovitis is a disease of the synovial inner layer of the tendon sheath with tendon infiltration and tendinitis. Pyogenic tenosynovitis favors the flexor compartments. Because of the narrow spaces in the hand, a high-resolution MRI technique must be used.

KEY POINTS

  · Diseases of the tendons and tendon sheaths may have a mechanical, degenerative, metabolic, systemic inflammatory, or infectious etiology.. · Fibrous tunnels and bony prominences in close proximity to crossing tendons predispose to mechanical tendon irritation at typical sites of the hand.. · Stenosing tenovaginitis occurs in the fibrous layer of the extensor retinaculum or the A1 annular pulleys. The most frequent manifestations are the "trigger finger" and de Quervain disease.. · Proliferative tenosynovitis affects the synovial layer of the tendon sheaths before infiltrating the tendons. The classic representative is rheumatoid arthritis..

CITATION FORMAT

· Schmitt R, Hesse N, Grunz JP. Tendons and Tendon Sheaths of the Hand - An Update on MRI. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1826-1007.

Ultrasound-detected tenosynovitis as a risk factor for flares in rheumatoid arthritis patients in clinical remission

BACKGROUND

Our objective was to investigate the value of ultrasound (US) detected synovitis and tenosynovitis as risk factors for short term flare in rheumatoid arthritis (RA) patients in clinical remission.

METHODS

Consecutive RA patients in clinical remission (DAS28 ERS < 2.6) for at least 3 months underwent Power Doppler ultrasound (PDUS) examination of 1st to 6th extensor compartments at the wrist, 2nd to 5th finger flexor, posterior tibial tendon, and peroneal tendons. To assess synovitis, carpal joints, 1st to 5th metacarpophalangeal (MCP) joints, and 2nd to 5th interphalangeal proximal (IPP) joints were bilaterally examined. Synovitis and tenosynovitis were defined according to OMERACT. Patients were followed for 1 year. Disease flare was defined as an increase in disease activity generating the need for a change in therapy by the attending rheumatologist.

RESULTS

Ninety patients were included. After 1 year of follow-up, 26 patients (29%) experienced a flare. At baseline 39%, 23% and 8% had US-detected synovitis, tenosynovitis or both, respectively. In the 1-year period after the baseline US examination, US-detected tenosynovitis (RR: 4.9; 95% CI: 2.2-10.8) was associated with an increased risk of exacerbation. This association was not shown with US-detected synovitis (RR: 1.3; 95% CI: 0.76-2.2). In the multivariate analysis, only subclinical tenosynovitis (OR: 9.8; 95% CI: 2.5-39.1; p = 0.001) and baseline DAS28 (OR: 5.7; 95% CI: 1.1-31.6; p = 0.047) were significantly associated with an increased risk of having a flare.

CONCLUSION

In our study, subclinical tenosynovitis was associated with disease flare in patients with RA in clinical remission.

KEY POINTS

• Synovitis and tenosynovitis are risk factors for short term flare in RA patients in clinical remission. • Subclinical tenosynovitis, but not synovitis, was associated with disease flare in patients with unstable remission. • Ultrasound-detected tenosynovitis could be useful to predict relapses in RA patients in clinical remission.

During development of rheumatoid arthritis, intermetatarsal bursitis may occur before clinical joint swelling: a large imaging study in patients with clinically suspect arthralgia

Objectives

Intermetatarsal bursitis (IMB) represents juxta-articular synovial inflammation of the intermetatarsal bursae. Recent MRI studies identified IMB as feature of early RA, but whether IMB already occurs in the pre-arthritic phase is unknown. We performed a large MRI study in clinically suspect arthralgia (CSA) to assess the occurrence and prognostic value of IMB.

Methods

A total of 577 consecutive CSA patients underwent contrast-enhanced MRI of the forefoot, metacarpophalangeal joints and wrist. MRIs were evaluated for subclinical synovitis/tenosynovitis/osteitis in line with the RA MRI scoring system (summed as RAMRIS inflammation) and for IMB. IMB was considered present if uncommon in the general population at the same location (i.e. size scored above the 95th percentile in age-matched symptom-free controls). The relation of IMB with other MRI-detected subclinical inflammation (synovitis/tenosynovitis/osteitis) was studied. Cox-regression assessed the association with clinical arthritis development during median 25 months follow-up. ACPA stratification was performed.

Results

At presentation with CSA, 23% had IMB. IMB was more frequent in ACPA-positive than ACPA-negative CSA (47% vs 19%, P < 0.001). Patients with IMB were more likely to also have subclinical synovitis [OR 3.4 (95% CI 1.8, 6.5)] and tenosynovitis [5.9(2.8, 12.6)]. IMB conferred higher risk of developing arthritis [HR 1.6(1.0–2.7) adjusted for other subclinical inflammation]. IMB-presence predicted arthritis development in ACPA-positive CSA [adjusted HR 2.2(1.0–4.7)], but not in ACPA-negative CSA-patients [0.8(0.4–1.7)].

Conclusion

Approximately a quarter of CSA patients have IMB, which is frequently accompanied by subclinical synovitis and tenosynovitis. IMB precedes development of clinical arthritis, particularly in ACPA-positive CSA. These results reinforce the notion that juxta-articular synovial inflammation is involved in the earliest phases of RA development.

Systematic review of imaging tests to predict the development of rheumatoid arthritis in people with unclassified arthritis

OBJECTIVE

To estimate and compare the diagnostic accuracy of magnetic resonance imaging (MRI) and ultrasound, for the prediction of rheumatoid arthritis (RA) in unclassified arthritis (UA).

METHODS

MEDLINE, Embase and BIOSIS were searched from 1987 to May 2019. Studies evaluating any imaging test in participants with UA were eligible. Reference standards were RA classification criteria or methotrexate initiation. Two authors independently extracted data and assessed validity using QUADAS-2. Sensitivities and specificities were calculated for each imaging characteristic and joint area. Summary estimates with 95% confidence intervals (CI) were estimated where possible.

RESULTS

Nineteen studies were included; 13 evaluated MRI (n=1,143; 454 with RA) and 6 evaluated ultrasound (n=531; 205 with RA). Studies were limited by unclear recruitment procedures, inclusion of patients with RA at baseline, differential verification, lack of blinding and consensus grading. Study heterogeneity largely precluded meta-analysis, however summary sensitivity and specificity for MRI synovitis in at least one joint were 93% (95% CI 88%, 96%) and 25% (95% CI 13%, 41%) (3 studies). Specificities may be higher for other MRI characteristics but data are limited. Ultrasound results were difficult to synthesise due to different diagnostic thresholds and reference standards.

CONCLUSION

The evidence for MRI or ultrasound as single tests for predicting RA in people with UA is heterogeneous and of variable methodological quality. Larger studies using consensus grading and consistently defined RA diagnosis are needed to identify whether combinations of imaging characteristics, either alone or in combination with other clinical findings, can better predict RA in this population.

MRI detected synovitis of the small joints predicts rheumatoid arthritis development in large joint undifferentiated inflammatory arthritis

Objectives

New onset undifferentiated large joint inflammatory arthritis can be diagnostically challenging. It is unknown how often these patients progress to RA, and how they can be identified at first presentation. We assessed clinical and serological features associated with RA development in patients with an undifferentiated mono- or oligo-articular large joint arthritis, and with keen interest in whether an MRI of the small joints of the hand and foot would aid diagnosis.

Methods

Leiden Early Arthritis Clinic includes 4018 patients; this prospective study follows 221 consecutively included patients with new onset undifferentiated large joint arthritis. Baseline clinical data and serology were obtained. Forty-five patients had MRIs (hand and foot). MRIs were scored according to the OMERACT RAMRIS. Univariable and multivariable logistic regression were assessed. Test characteristics, predictive values and net reclassification index (NRI) for RA were determined.

Results

Patients mostly presented with knee or ankle mono-arthritis. During the 12 months’ follow-up 17% developed RA. Autoantibody positivity (ACPA and/or RF) and MRI-detected synovitis in hands and feet were independently associated with RA development in multivariable analyses [odds ratio 10.29 (P = 0.014) and 7.88 (P = 0.017), respectively]. Positive predictive value of autoantibodies, MRI-detected synovitis and combination of both features was 63%, 55% and 100%, respectively. The addition of MRI-detected synovitis to autoantibody status improved diagnostic accuracy (NRI 18.1%).

Conclusion

In patients presenting with undifferentiated large joint arthritis, 17% will develop RA. Autoantibody positivity and subclinical synovitis are independent predictors. The data suggest MRI of small joints is beneficial for early identification of RA in large joint arthritis.

Predictors of joint damage progression and stringent remission in patients with established rheumatoid arthritis in clinical remission

OBJECTIVES

To study if clinical, radiographic and MRI markers can predict MRI and radiographic damage progression and achievement of stringent remission in patients with established RA in clinical remission followed by a targeted treatment strategy.

METHODS

RA patients (DAS28-CRP <3.2, no swollen joints) receiving conventional synthetic DMARDs were randomized to conventional or MRI-targeted treat-to-target strategies with predefined algorithmic treatment escalations. Potentially predictive baseline variables were tested in multivariate logistic regression analyses.

RESULTS

In the 171 patients included, baseline MRI osteitis independently predicted progression in MRI erosion [odds ratio (OR) 1.13 (95% CI 1.06, 1.22)], joint space narrowing [OR 1.15 (95% CI 1.07, 1.24)] and combined damage [OR 1.23 (95% CI 1.13, 1.37)], while tenosynovitis independently predicted MRI erosion progression [OR 1.13 (95% CI 1.03, 1.25)]. A predictor of radiographic erosion progression was age, while gender predicted progression in joint space narrowing. Following an MRI treat-to-target strategy predicted stringent remission across all remission definitions: Clinical Disease Activity Index remission OR 2.94 (95% CI 1.25, 7.52), Simplified Disease Activity Index remission OR 2.50 (95% CI 1.01, 6.66), ACR/EULAR Boolean remission OR 5.47 (95% CI 2.33, 14.13). Similarly, low tender joint count and low patient visual analogue scale pain and global independently predicted achievement of more stringent remission.

CONCLUSION

Baseline MRI osteitis and tenosynovitis were independent predictors of 2 year MRI damage progression in RA patients in clinical remission, while independent predictors of radiographic damage progression were age and gender. Following an MRI treat-to-target strategy, low scores of patient-reported outcomes and low tender joint count predicted achievement of stringent remission.

TRIAL REGISTRATION

ClinicalTrials.gov (https://clinicaltrials.gov), NCT01656278.

Differentiating rheumatoid and psoriatic arthritis: a systematic analysis of high-resolution magnetic resonance imaging features-preliminary findings

BACKGROUND

Because of overlapping phenotypical presentations, the diagnostic differentiation of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) remains challenging. Thus, this study aimed to examine the diagnostic value of distinct imaging features obtained by high-resolution 3-T MRI for the diagnostic differentiation.

MATERIALS AND METHODS

Seventeen patients with PsA and 28 patients with RA were imaged at high resolution using 3-T MRI scanners and a dedicated 16-channel hand coil. All images were analyzed according to the outcome measures in rheumatology clinical trials' (OMERACT) RAMRIS (Rheumatoid Arthritis Magnetic Resonance Imaging Score) and PsAMRIS (Psoriatic Arthritis Magnetic Resonance Imaging Score) for the presence and intensity of synovitis, flexor tenosynovitis, bone edema, bone erosion, periarticular inflammation, bone proliferation, and joint space narrowing. Next, odds ratios (OR) were calculated to determine the strength of the associations between these imaging features, demographic characteristics, and the outcome RA vs. PsA.

RESULTS

PsA could be differentiated from RA by extracapsular inflammatory changes (PsAMRIS sub-score "periarticular inflammation"), with low odds for the presence of RA (OR of 0.06, p < 0.01) at all metacarpophalangeal (MCP) joints. A prediction model informed by the items that were strongest associated with the presence of RA or PsA demonstrated excellent differentiating capability with an area under the curve of 98.1%.

CONCLUSION

High-resolution imaging is beneficial for the identification of relevant imaging features that may assist the clinical differentiation of inflammatory conditions of the hand. At the MCP level, extracapsular inflammatory changes were strongly associated with PsA and may consequently allow the imaging differentiation of PsA and RA.

Contemporary imaging of rheumatoid arthritis: Clinical role of ultrasound and MRI

Magnetic resonance imaging (MRI) and musculoskeletal ultrasound (MSUS) are sensitive imaging modalities used by clinicians to assist in decision-making in the management of rheumatoid arthritis (RA). This review will examine the utility of MRI and MSUS in diagnosing RA, predicting RA flares, tapering therapy, assessing remission, and examining difficult periarticular features. We will also outline the strengths and weaknesses of utilizing MRI and MSUS as outcome measures in the management of RA.

Differentiating Rheumatoid and Psoriatic Arthritis of the Hand: Multimodality Imaging Characteristics

Accurate diagnosis and therapeutic intervention at an early stage is paramount for the management of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), which are the two major types of inflammatory arthritis that involve the hand joints. As more disease-specific medications are developed, medication selection according to the correct diagnosis becomes more important. A delay in diagnosis and inappropriate medication selection may result in poor functional prognosis. However, clinical differentiation between RA and PsA can be challenging and may become largely dependent on imaging interpretation results. Although there is substantial overlap in the imaging findings of RA and PsA, there are differences in the affected primary target sites, reflected by the various patterns of joint involvement, and different microanatomic localization of abnormalities within a single joint in each disease. Therefore, appropriate use of various imaging modalities and accurate image interpretation add significant value to the diagnosis and treatment process. The synovio-entheseal complex is an important concept for understanding the imaging features of PsA. The authors review the different features of RA and PsA of the hands seen with various imaging modalities, including radiography, US, MRI, and dual-energy CT, with updates on the contemporary role of imaging in diagnosis and treatment. The radiologist should have sufficient knowledge to interpret imaging findings and understand the strengths and weaknesses of each modality to recommend the appropriate imaging method and differentiate both diseases accurately. ^©RSNA, 2020.

Ultrasound assessment of carpal tunnel in rheumatoid arthritis and idiopathic carpal tunnel syndrome

Objectives

To comparatively assess the sonographic spectrum of carpal tunnel syndrome (CTS) in patients with rheumatoid arthritis (RA) and in patients with idiopathic CTS.

Methods

Fifty-seven RA patients and 25 idiopathic CTS patients were consecutively enrolled. The diagnosis of CTS in RA patients was made according to clinical history and examination. The following sonographic findings were assessed at carpal tunnel level: median nerve cross-sectional area (CSA) at the carpal tunnel proximal inlet, finger flexor tendons tenosynovitis, radio-carpal synovitis and intraneural power Doppler (PD) signal.

Results

CTS was diagnosed in 15/57 RA patients (26.3%). Twenty-three RA wrists with CTS, 84 RA wrists without CTS and 34 idiopathic CTS wrists were evaluated. The average CSA of the median nerve was higher in idiopathic CTS than in RA wrists with CTS (17.7 mm² vs 10.6 mm², p < 0.01). A higher rate of inflammation of synovial structures (flexor tendons sheath and/or radio-carpal joint) was found in RA wrists with CTS compared with those without CTS (p = 0.04) and idiopathic CTS (p = 0.02). Intraneural PD signal was more common in CTS (in both RA and idiopathic CTS) wrists compared with wrists without CTS (p < 0.01).

Conclusion

The sonographic spectrum of CTS in RA patients is characterized by an inflammatory pattern, defined by the presence of finger flexor tendons tenosynovitis and/or radio-carpal joint synovitis. Conversely, a marked median nerve swelling is the dominant feature in idiopathic CTS. Intraneural PD signal is a frequent finding in both conditions.

Key Points • Carpal tunnel syndrome (CTS) associated with rheumatoid arthritis (RA) and idiopathic CTS have distinct ultrasound patterns. • The most characteristic sonographic features of CTS in RA patients are those indicative of synovial tissue inflammation at carpal tunnel level. Conversely, marked median nerve swelling is the dominant finding in idiopathic CTS. • Intraneural power Doppler signal is a frequent finding in both conditions. • In patients with CTS, differently from electrophysiology, US can provide clues prompting a rheumatology referral in case of prominent inflammatory findings at carpal tunnel level.

Ultrasonography in Early Rheumatoid Arthritis of Hand and Wrist Joints: Comparison with Magnetic Resonance Imaging

BACKGROUND

The aim of the study was to evaluate the use of ultrasonography (USG) including power Doppler in detecting hand and wrist joint changes in early rheumatoid arthritis (RA) and to compare USG findings with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Thirty-four patients diagnosed as RA by 2010 ACR/EULAR criteria; with the onset of symptoms within last one year, were included in the study after institute ethical clearance and informed consent to undergo USG and contrast-enhanced MRI of the dominant affected hand. Second to fifth metacarpophalangeal (MCP) joints, second to fifth proximal interphalangeal (PIP) joints and wrist joints (total nine joints) were evaluated for synovitis, erosions along with tenosynovitis. USG and MRI features were compared; agreement on the two imaging modalities as well as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of ultrasonography compared to MRI (gold standard) was calculated.

RESULTS

One hundred thirty-six MCP, 136 PIP and 34 wrist joints (total 306 joints) and 136 flexor tendons were evaluated. The sensitivity, specificity, PPV, NPV and diagnostic accuracy of USG for diagnosing synovitis was 78.6%, 91.1%, 86.1%, 85.8%, 86.3%; for erosions 67.2%, 97.5%, 84.8%, 90.5%, 91.5%; for tenosynovitis 86.5%, 100%, 100%, 92.3% and 94.8% respectively. The overall agreement between USG and MRI for detection of synovitis was achieved in 83% joints and for erosions in 89.5% joints.

CONCLUSION

In early RA, USG was nearly as effective in diagnosing features of joint and tendon sheath involvement, with relatively better performance of USG for tenosynovitis. The performance of USG in diagnosing erosions was limited likely due to difficult access of three-dimensional joint structure.

Rheumatoid Arthritis and Tenosynovitis at the Metatarsophalangeal Joints: An Anatomic and MRI Study of the Forefoot Tendon Sheaths

Background Although tenosynovitis in the hands is associated with rheumatoid arthritis (RA), it is unknown whether tenosynovitis of the forefoot is associated with RA. Purpose To determine the anatomy of tendon sheaths of the forefoot and the relationship between MRI-detected tenosynovitis at metatarsophalangeal (MTP) joints and RA. Materials and Methods Fourteen forefeet of donated bodies were examined at flexor tendons and extensor tendons for the presence and course of tendon sheaths. In the prospective study between June 2013 and March 2016, newly presenting patients with RA, patients with other early arthritides, and healthy control participants all underwent MRI of unilateral MTP joints 1-5. MRI studies were scored by two independent readers for tenosynovitis, synovitis, and bone marrow edema. The association between the presence of these features and RA was examined by using logistic regression. Results Macroscopically, all extensor and flexor tendons crossing MTP joints demonstrated sheaths surrounding tendons. Microscopically, a synovial sheath was present. MRI evaluation was performed in 634 participants: 157 newly presenting patients with RA (109 women; mean age, 59 years ± 11 [standard deviation]), 284 patients with other early arthritides (158 women; mean age, 56 years ± 17), and 193 healthy control participants (136 women; mean age, 50 years ± 16). MRI-detected tenosynovitis was associated with RA, both when compared with patients with other arthritides (odds ratio [OR], 2.5; 95% confidence interval [CI]: 1.7, 3.9; P < .001) and healthy control participants (OR, 46; 95% CI: 14, 151; P < .001). The association was OR of 2.4 (95% CI: 1.5, 3.8; P < .001) for flexor tendons and OR of 3.1 (95% CI: 1.9, 5.2; P < .001) for extensor tendons. The sensitivity of tenosynovitis in RA was 65 of 157 (41%; 95% CI: 35%, 50%). The specificity for RA was 63 of 284 (78%; 95% CI: 72%, 82%) compared with other arthritides, and three of 193 (98%; 95% CI: 96%, 99%) compared with healthy control participants. Conclusion Tendons at metatarsophalangeal joints are surrounded by tenosynovium. MRI-detected tenosynovitis at metatarsophalangeal joints was specific for rheumatoid arthritis when compared with findings in patients with other arthritides and findings in healthy control participants. © RSNA, 2020 Online supplemental material is available for this article.

Use of Magnetic Resonance Imaging to Identify Immune Checkpoint Inhibitor-Induced Inflammatory Arthritis

IMPORTANCE

Immune checkpoint inhibitors (ICIs) have transformed the treatment paradigm for an ever-increasing number of cancers. However, their use has also led to the emergence of immune-related adverse events, such as ICI-induced inflammatory arthritis. A reproducible, reliable, and accessible modality is needed to assess and distinguish early ICI-induced inflammatory arthritis and help in management. Magnetic resonance imaging (MRI) of joints may be helpful for early diagnosis, guiding therapeutic decision-making, and identifying patients at high risk for erosive disease.

OBJECTIVE

To assess the role of MRI of joints in patients with ICI-induced inflammatory arthritis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective case series included patients enrolled at the National Institutes of Health Clinical Center in Bethesda, Maryland. Patients were evaluated by the rheumatology consultation service between December 27, 2016, and May 28, 2019. A retrospective health record review was performed to determine demographic characteristics, clinical characteristics of inflammatory arthritis and malignant tumors, and imaging findings. Inclusion criteria were patients who were enrolled on various institutional review board-approved protocols of ICIs, developed joint-related symptoms, and had MRI data for at least 1 joint. Data were analyzed from June 1, 2019, to September 1, 2019.

EXPOSURES

Undergoing MRI of at least 1 joint.

MAIN OUTCOMES AND MEASURES

All MRIs were reviewed for synovitis, tenosynovitis, bone marrow edema, and soft tissue conditions.

RESULTS

A total of 8 patients (mean [SD] age, 58.8 [5.2] years; 6 women and 2 men) between the ages of 50 and 65 years who were undergoing ICI therapy for a variety of malignant tumors were included in this study. Only 1 patient was receiving combined ICI therapy. The results of 13 separate MRI examinations were reviewed. The most commonly performed MRIs were of the hands and wrists (9 MRIs), followed by knee examinations (3 MRIs). Tenosynovitis and synovitis were frequently seen in the hands and wrists. Bone marrow edema and erosions were also found in 3 patients, suggesting early damage. In larger joints (ie, knees and ankles), joint effusions and synovial thickening were characteristic. Most patients (5 patients) were treated with corticosteroids and had good responses. In patients with high-risk features on MRI imaging (eg, bone marrow edema, erosions), disease-modifying antirheumatic drug therapy was also discussed as a treatment option.

CONCLUSIONS AND RELEVANCE

These findings suggest that advanced imaging may help to distinguish ICI-induced inflammatory arthritis from other causes of joint pain, aid in identifying patients at increased risk of joint damage, and provide utility in monitoring inflammatory arthritis treatment response in patients receiving ICI therapy.

Thenar lumps: a review of differentials

Most soft-tissue lumps in the hand are benign, with ganglions being the commonest, but in the thenar region, solid soft-tissue masses are more common than a ganglion. In this review, we focus on soft-tissue lesions (neoplastic and non-neoplastic) presenting as a palpable lump in this region. A specific diagnosis can often be reached using ultrasonography and/or magnetic resonance imaging. Most of these lesions are managed in local hospitals or primary care, whereas some are referred to specialist centres. This review article will help both general and musculoskeletal radiologists to diagnose and characterise these lesions, provide a guide for further imaging, and provide an insight into imaging features that may need specific investigations such as core biopsy, tertiary referral, and further review at multidisciplinary meetings.

The Correlation Between Tenosynovitis Pattern on Two-Phase Bone Scintigraphy and Clinical Manifestation in Patients with Suspected Rheumatoid Arthritis

Purpose

To investigate the correlation between the tenosynovitis pattern on two-phase bone scintigraphy (2P-BS) and clinical manifestation in patients with suspected rheumatoid arthritis (RA).

Method

2P-BS including technetium-99m-methylene diphosphonate blood pool and bone phase imaging in 402 consecutive patients with clinically suspected RA were retrospectively reviewed. According to 2010 RA Classification Criteria, patients were grouped as RA and non-RA. Visual assessment of all fingers, toes, wrists, and ankles on 2P-BS was performed. Clinical suspected tenosynovitis was evaluated on physical examination. Rheumatoid factor, anti-cyclic citrullinated protein antibody, C-reactive protein, and estimated sedimentation rate were obtained. Radiographic findings were also used to define early and established arthritis.

Results

Tenosynovitis pattern was detected in 12.7% (51/402 patients) on 2P-BS. A total of 94.1% (48/51) were diagnosed as RA vs. 5.9% (3/51) as non-RA. Of the 48 RA patients with positive 2P-BS finding, 85.4% (41/48) had early arthritis and 14.6% (7/48) had established arthritis. On physical examination, tenosynovitis was suspected in 21.9% (88/402). A total of 56.8% (50/88) belonged to the RA group and 43.2% (38/88) to the non-RA group. The tenosynovitis pattern of 2P-BS and physical examination showed statistical difference and moderate agreement. The positive tenosynovitis pattern on 2P-BS represented up to 26.408 of odds ratio which was highest among the RA-associated factors.

Conclusion

Tenosynovitis pattern on 2P-BS was more commonly detected in the RA group and was more frequently associated with early arthritis pattern. Therefore, 2P-BS could give additional information for the detection of subclinical tenosynovitis in early or preclinical RA patients.

MR and ultrasound of the hands and wrists in rheumatoid arthritis. Part II. Added clinical value

Advanced imaging has become just as vital for diagnosing, staging, and monitoring disease in rheumatoid arthritis (RA) patients as it is for cancer patients. Part 1 of this review discussed synovitis, tenosynovitis, erosions, and osteitis-key imaging findings that occur in patients with RA. Part 2 will now show how these features, in combination with clinical and serologic data, can assist clinical decision-making at various stages of a patient's disease course. Specifically, assessing current disease activity and prognosticating future aggressiveness inform treatment decisions at initial presentation, during medical treatment, and at clinical remission. In addition to summarizing the current literature on advanced imaging in RA, clinical examples from different stages throughout the disease course will illustrate practical approaches for applying these research results. Last, this review will describe potential future roles of imaging in RA patients.

MRI and ultrasound of the hands and wrists in rheumatoid arthritis. I. Imaging findings

The management of patients with rheumatoid arthritis (RA) has rapidly evolved with the development of newer disease-modifying drugs and the recognition that long-term damage can be mitigated by an earlier and more-informed use of these medications. Historically, radiographs were the mainstay of imaging in RA patients, but radiographic joint narrowing and erosions are late and insensitive findings in the disease. MRI (with intravenous contrast agent) and ultrasound (with power Doppler interrogation) of the hands and wrists are able to demonstrate erosions earlier and with greater sensitivity than radiographs. More importantly, these imaging studies also depict synovitis and active soft-tissue inflammation, which represents a precursor to structural damage. Additionally, MRI can show inflammation within the bones (osteitis), which is proving to be the most important prognosticator of an aggressive disease course. Part I of this review discusses the imaging techniques, pitfalls, definitions, and comparative studies of MRI and ultrasound for identifying and quantifying erosions, synovitis, and osteitis. Part II will demonstrate how these imaging findings influence the clinical management of RA patients throughout their disease course, from presentation through clinical remission.

The correlation between interleukin-34 and bone erosion under ultrasound in rheumatoid arthritis

Background: Rheumatoid arthritis (RA) is a chronic inflammatory arthropathy characterized by excessive synovial hyperplasia and progressive joint destruction. Pro-inflammatory cytokines play major roles in the regulation of synovial inflammation. The contribution of interleukin-34 (IL-34) in RA pathogenesis has been strongly suggested in clinical studies.Aim: To investigate the correlation between plasma IL-34 and disease parameters in RA patients including disease activity score (DAS28), receptor activator of NF-[Formula: see text]B ligand (RANKL) concentration, synovitis and bone erosions under ultrasound.Methods: 60 RA patients and 20 healthy controls were from Huashan Hospital, patient's medical history, physical examination, laboratory examination and ultrasound data were collected and recorded, respectively. Blood samples of all participants were collected and the levels of IL-34 and RANKL were tested. The levels of IL-34 and RANKL in RA patients were compared with those of healthy controls. Furthermore, the correlation between IL-34, RANKL and disease parameters in RA patients was analyzed.Results: Both plasma levels of IL-34 and RANKL in RA patients were significantly higher than the healthy controls (p < .05). IL-34 was significantly related to disease activity scores (r = 0.43, p = .001); RANKL (r = 0.46, p = .0003) and bone erosions by ultrasound (r = 0.38, p = .002).Conclusions: The plasma IL-34 concentration in RA was significantly higher than the healthy controls and was significantly correlated with RANKL, as well as disease activity score and bone erosions by ultrasound. The IL-34 may be a new biological marker for disease activity and predictor for bone erosions in RA. Targeting IL-34 holds promise in the management of RA and, potentially, other osteoclasts driven diseases (erosive osteoarthritis and psoriatic arthritis for example).

Sonographic findings from inflammatory arthritis due to antisynthetase syndrome

Inflammatory arthritis is a common feature of antisynthetase syndrome. Ultrasonography is able to characterize important features of bone and tendon pathology but has not been evaluated in this setting. We review the sonographic findings in a series of patients with antisynthetase syndrome and inflammatory arthritis. A retrospective chart review was performed of patients with antisynthetase syndrome-associated inflammatory arthritis who had undergone ultrasound imaging for joint pathology. Seventeen sonographic assessments of eight patients were included. Synovial hypertrophy was seen in all eight patients, with active Doppler signal present in six patients (13 of 17 ultrasound locations). Tendon involvement was common, with tenosynovitis in seven patients (11 of 17 ultrasound locations). Erosions were present in five patients. Musculoskeletal ultrasound showed significant joint pathology including proliferative synovitis and tenosynovitis. This may be severe and associated with erosive disease. Further systematic studies are needed to better understand the articular involvement of antisynthetase syndrome. Key points • Marked inflammatory change-with proliferative synovitis, tenosynovitis, and erosions-can be seen in selected patients with antisynthetase syndrome (ASyS). • Inflammatory arthritis from ASyS can be severe and erosive in the absence of RF and ACPA and can be refractory to immunosuppressive therapy used to manage the myositis and interstitial lung disease. • Systematic sonographic evaluation of patients with ASyS is needed to further evaluate pathology and treatment response of inflammatory arthritis.

What is the additional value of MRI of the foot to the hand in undifferentiated arthritis to predict rheumatoid arthritis development?

Background

MRI-detected subclinical joint inflammation in the hand joints of patients with undifferentiated arthritis (UA) predicts progression to rheumatoid arthritis (RA). It is unknown if adding MRI of the foot increases predictive accuracy compared to the hand alone.

Methods

1.5-T contrast-enhanced MRI of the unilateral foot (MTP-1-5) and hand (MCP-2-5 and wrist) was performed in 123 patients presenting with UA (not fulfilling the 2010 RA criteria) and scored for bone marrow edema (BME), synovitis and tenosynovitis. Symptom-free controls (n = 193) served as a reference for defining an abnormal MRI. Patients were followed for RA development ≤ 1 year, defined as fulfilling the classification criteria or initiation of disease-modifying antirheumatic drugs because of the expert opinion of RA. The added predictive value of foot MRI to hand MRI was evaluated.

Results

Fifty-two percent developed RA. Foot tenosynovitis was predictive (OR 2.55, 95% CI 1.01–6.43), independent of BME and synovitis (OR 3.29, 95% CI 1.03–10.53), but not independent of CRP and number of swollen joints (OR 2.14, 95% CI 0.77–5.95). Hand tenosynovitis was also predictive independent of BME and synovitis (OR 3.99, 95% CI 1.64–9.69) and independent of CRP and swollen joints (OR 2.36, 95% CI 1.04–5.38). Adding foot tenosynovitis to hand tenosynovitis changed the sensitivity from 72 to 73%, specificity from 59 to 54% and AUC from 0.66 to 0.64; the net reclassification index was − 3.5.

Conclusion

MRI-detected tenosynovitis of the foot predicts progression to RA. However, adding MRI of the foot does not improve the predictive accuracy compared to MRI of the hand alone. In view of cost reduction, the performance of foot MRI for prognostic purposes in UA can be omitted.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1845-7) contains supplementary material, which is available to authorized users.

Patients with Rheumatoid Arthritis Were Associated with a Risk of Rotator Cuff Diseases

Rheumatoid arthritis (RA) commonly causes inflammation in the joints and periarticular structures. The association between RA and rotator cuff (RC) has been reported; however, epidemiological studies on RA and RC tendons are scant. Therefore, we investigated RC disease (RCD) risk and analyzed the effects of RA medication, steroids, and methotrexate, on the risk of RCD for patients with RA. We conducted a retrospective cohort study with a 6-year longitudinal follow-up in Taiwan. Patients who received RA diagnoses between 2004 and 2008 were enrolled in the study cohort. The non-RA control cohort comprised age- and sex-matched controls. Propensity score matching was used for other comorbidities and treatments. The hazard ratios (HRs) and adjusted HRs (aHRs) were estimated after confounders were adjusted for. Effects of steroid and methotrexate use on RCD risk were also analyzed. We enrolled 4521 RA patients (study cohort) and 22,605 matched controls. RCD incidence was 145 and 91 per 100,000 person-years in the RA and control cohorts, respectively. In the RA cohort, the crude HR for RCD was 1.62 (95% confidence interval (CI), 1.41–1.86, p < 0.001), and the aHR was 1.56 (95% CI, 1.36–1.79, p < 0.001). The methotrexate nonusers exhibited an aHR (vs. controls) of 1.61 (95% CI, 1.40–1.85, p < 0.001), but the methotrexate users did not have a significantly higher aHR than the controls. The steroid nonusers had an aHR (vs. controls) of 1.69 (95% CI, 1.46–1.96, p < 0.001), but the aHR of the steroid users was not significantly higher than the control aHR. Patients with RA had a higher risk for RCD compared with the non-RA control cohort. Steroids or methotrexate use significantly reduces the risk of RCD occurrence in patients with RA. Treatment for RCD symptoms and controlling inflammatory process are important to ensure high-quality care for patients with RA.

The role of ultrasound-defined tenosynovitis and synovitis in the prediction of rheumatoid arthritis development

OBJECTIVES

Tenosynovitis (TS) is common in early arthritis. However, the value of US-defined TS in predicting RA development is unclear. We assessed the predictive utility of US-defined TS alongside US-defined synovitis and clinical and serological variables in a prospective cohort of early arthritis patients.

METHODS

One hundred and seven patients with clinically apparent synovitis of one or more joint and symptom duration ⩽3 months underwent baseline clinical, laboratory and US assessment of 19 bilateral joint sites and 16 bilateral tendon compartments. Diagnostic outcome was determined after 18 months, applying the 2010 ACR/EULAR classification criteria for RA. The predictive values of US-defined TS for persistent RA were compared with those of US-defined synovitis, clinical and serological variables.

RESULTS

A total of 4066 US joint sites and 3424 US tendon compartments were included in the analysis. Forty-six patients developed persistent RA, 17 patients developed non-RA persistent disease and 44 patients had resolving disease at follow-up. US-defined TS in at least one tendon compartment at baseline was common in all groups (RA 85%, non-RA persistent disease 71% and resolving 70%). On multi-variate analysis, US-defined digit flexor TS provided independent predictive data over and above the presence of ACPA and US-defined joint synovitis.

CONCLUSION

US-defined digit flexor TS provided independent predictive data for persistent RA development in patients with early arthritis. The predictive utility of this tendon site should be further assessed in a larger cohort; investigators designing imaging-based predictive algorithms for RA development should include this tendon component as a candidate variable.

The Use of the OMERACT Ultrasound Tenosynovitis Scoring System in Multicenter Clinical Trials

OBJECTIVE

To test the sensitivity to change of the Outcome Measures in Rheumatology Clinical Trials (OMERACT) ultrasound (US) scoring system for tenosynovitis when applied in a multicenter design.

METHODS

RA patients with US-verified tenosynovitis were recruited when scheduled for treatment intensification. Tenosynovitis was assessed at baseline, and 3 and 6 months followup, using the semiquantitative OMERACT scoring system.

RESULTS

Expressed in median (25th; 75th percentiles), the overall greyscale and Doppler score decreased significantly from baseline at 4 (2; 7) and 3 (2; 6), to 6 months at 2 (0; 3) and 0 (0; 1, p < 0.01), respectively, and showed high responsiveness (standardized response mean ≥ 0.8).

CONCLUSION

The OMERACT US scoring system for tenosynovitis showed high responsiveness, supporting its use for diagnosing and monitoring tenosynovitis in multicenter trials.

Adult Inflammatory Arthritides: What the Radiologist Should Know

Developments and improvements in knowledge are rapid and ongoing in both the radiologic and rheumatologic fields. During the past decade, the roles of imaging and the radiologist in the assessment and management of many inflammatory rheumatologic diseases have undergone several changes. To remain effective in patient care, the radiologist needs to be aware of these changes when recommending and interpreting imaging examinations for the referring physician. The goal of contemporary rheumatoid arthritis (RA) management is to redefine RA as a disease that is no longer characterized by erosions, which reflect established or long-standing untreated disease. Most cases of RA are now diagnosed clinically, but imaging increases diagnostic confidence, is superior to clinical examination for the detection of joint inflammation, and plays an important role in patient management. The concept of the seronegative spondyloarthritides has recently been redefined by the Assessment of SpondyloArthritis International Society (ASAS). This new set of ASAS classification criteria divides the spectrum of spondyloarthritis on the basis of predominantly axial skeletal clinical manifestations or predominantly peripheral skeletal clinical manifestations. For axial spondyloarthritis, magnetic resonance imaging and radiography play crucial roles for classification and diagnosis. For both peripheral spondyloarthritis and psoriatic arthritis, the radiologist can provide important information that influences classification and diagnosis, including documenting radiologic evidence of juxta-articular new bone formation, diagnosing sacroiliitis, or delineating the presence and extent of enthesitis and dactylitis. The radiologist's familiarity with recent classification criteria, in addition to the traditional diagnostic characteristics of the individual inflammatory arthritides, maximizes the productive interface between the radiologist and the rheumatologist. ^©RSNA, 2016.

Evaluation of the diagnostic accuracy of hand and foot MRI for early Rheumatoid Arthritis

Objectives

To assess the diagnostic value of MRI for early RA. In some RA patients, a classifiable diagnosis cannot be made at first presentation; these patients present with unclassified arthritis (UA). The use of MRI for early diagnosis of RA is recommended, yet the evidence for its reliability is limited.

Methods

MRI of hand and foot was performed in 589 early arthritis patients included in the Leiden Early Arthritis Clinic (229 presented with RA, 159 with other arthritides and 201 with UA). Symptom-free controls provided a reference for defining an abnormal MRI. In preliminary investigations, MRI of patients who presented with RA was compared with MRI of symptom-free controls and of patients with other arthritides. Thereafter, the value of MRI in early RA diagnosis was determined in UA patients using the 1-year follow-up on fulfilling the 1987 RA criteria and start of disease-modifying drugs as outcomes.

Results

Preliminary investigations were promising. Of the UA patients, 14% developed RA and 37% started disease-modifying treatment. MRI-detected tenosynovitis was associated with RA development independent of other types of MRI-detected inflammation [odds ratio (OR) = 7.5, 95% CI: 2.4, 23] and also independent of age and other inflammatory measures (swollen joints, CRP) (OR = 4.2, 95% CI: 1.4, 12.9). Within UA patients, the negative predictive value of abnormal tenosynovitis was 95% (95% CI: 89%, 98%) and the positive predictive value 25% (95% CI: 17%, 35%). The performance was best in the subgroup of UA patients presenting with oligoarthritis (18% developed RA): the positive predictive value was 36% (95% CI: 23%, 52%), the negative predictive value was 98% (95% CI: 88%, 100%), the sensitivity was 93% (95% CI: 70%, 99%) and the specificity was 63% (95% CI: 51%, 74%).

Conclusion

MRI contributes to the identification of UA patients who will develop RA, mostly in UA patients presenting with oligoarthritis.

Examining the validity of the rheumatoid arthritis magnetic resonance imaging score according to the OMERACT filter-a systematic literature review

Objective

To examine whether the RA MRI score (RAMRIS) for RA of the wrist/hand meets the OMERACT filter criteria-truth (validity), discrimination and feasibility.

Methods

We conducted a systematic literature review in PubMed and Scopus, from 1970 through June 2014, focused on MRI measures of synovitis, osteitis/bone marrow oedema, erosions and/or joint space narrowing in RA randomized controlled trials and observational studies with cohort size ⩾10. Strength of evidence was assessed using the Cochrane Handbook criteria.

Results

Of 634 MRI titles/abstracts, 202 met the review criteria, with 92 providing at least 1 type of validity. Four articles provided criterion validity, and 26 articles utilized RAMRIS to assess 1.5 T MRI images. Histopathology data showed inflammation corresponding to MRI of synovitis and osteitis. MRI erosions corresponded to those identified with CT. Content and construct validity for RAMRIS synovitis, osteitis and erosions were documented by correlations with clinical, laboratory and/or radiographic data. Each measure was sensitive to change and responsive to therapy. RAMRIS synovitis and osteitis were able to discriminate between the efficacy of treatments vs placebo in 12-week studies, whereas RAMRIS erosions required studies of ⩾24 weeks.

Conclusion

RAMRIS synovitis, osteitis and erosions imaged with 1.5 T MRI are valid and useful for evaluating joint inflammation and damage for RA of the wrist/hand, according to the OMERACT filter.

Sonographic Characteristics of Extensor Tendon Abnormalities and Relationship With Joint Disease Activity in Rheumatoid Arthritis: A Pilot Study

OBJECTIVES

To characterize abnormalities in the dorsal extensor tendons of the hand and determine the importance of these findings in rheumatoid arthritis.

METHODS

A retrospective cross-sectional study was done on 26 patients with rheumatoid arthritis who had sonography of their hands. B-mode and power Doppler joint activity were scored, and the extensor tendons were examined for B-mode changes and power Doppler signals. B-mode changes included anechoic fluid around tendons, hypoechoic tissue around tendons, paratendon tissue and tendon thickening, as well as vascularity around the tendon, for which peritendon power Doppler signals were recorded.

RESULTS

Forty-one hands and 205 joints were reviewed. Anechoic fluid around the tendons and peritendon power Doppler signals were observed in 41% and 39%, respectively; 44% and 28% of patients had B-mode and power Doppler scores in the upper tertile, respectively. For both B-mode and power Doppler scores, 3 categories or tertiles were created, 0 to 0.9, 1 to 1.9, and 2 to 3. We reported the percentage of patients with power Doppler and B-mode scores in this category. The severity of synovitis was associated with anechoic fluid around the tendons and peritendon power Doppler signals according to the Cochran-Mantel-Haenszel test. The common odds ratio was 3.52 (95% confidence interval, 1.45- 8.53) for anechoic fluid around the tendons and severe synovitis. The common odds ratio was 2.52 (95% confidence interval, 1.13-5.63) for peritendon power Doppler signals and severe synovitis.

CONCLUSIONS

Findings at the dorsal extensor tendons were anechoic fluid around tendons, hypoechoic tissue around tendons, peritendon power Doppler signals, and tendon thickening. Patients with anechoic fluid and power Doppler signals were found to have more severe disease activity at the joints based on B-mode and power Doppler scores.

Development and Validation of the OMERACT Rheumatoid Arthritis Magnetic Resonance Tenosynovitis Scoring System in a Multireader Exercise

OBJECTIVE

To develop and validate a magnetic resonance imaging (MRI) tenosynovitis (TS) score for tendons at the wrist and metacarpophalangeal (MCP) joint levels in patients with rheumatoid arthritis (RA).

METHODS

Axial T1-weighted precontrast and postcontrast fat-saturated MR image sets of the hands of 43 patients with RA initiating rituximab therapy were obtained at baseline and after 14, 26, 38, or 52 weeks. The MR images were scored twice by 4 readers. Nine tendon compartments of the wrist and 4 flexor tendon compartments at the MCP joints were assessed. Tenosynovitis was scored as follows: 0: No; 1: < 1.5 mm; 2: ≥ 1.5 mm but < 3 mm; 3: ≥ 3 mm peritendinous effusion and/or postcontrast enhancement. Intrareader and interreader intraclass correlation coefficients (ICC), smallest detectable change (SDC), percentage of exact and close agreement (PEA/PCA), and standardized response mean (SRM) were calculated.

RESULTS

Intrareader and interreader ICC for status and change scores were very good (≥ 0.80) for total scores for all readers. Intrareader SDC was ≤ 3.0 and interreader SDC was < 2.0. The overall PEA/PCA intrareader and interreader agreements for change scores in all tendons were 73.8%/97.6% and 47.9%/85.0%, respectively. Average SRM was moderate for total scores and 60.5% of the patients had a tenosynovitis change score ≥ SDC.

CONCLUSION

The TS score showed high intrareader and interreader agreement for wrist and finger tendons, with moderate responsiveness, and the majority of the patients showed a change above the SDC. This scoring system may be included as a component of the RAMRIS.

Validity and sensitivity to change of the semi-quantitative OMERACT ultrasound scoring system for tenosynovitis in patients with rheumatoid arthritis

OBJECTIVES

The aim was to evaluate the metric properties of the semi-quantitative OMERACT US scoring system vs a novel quantitative US scoring system for tenosynovitis, by testing its intra- and inter-reader reliability, sensitivity to change and comparison with clinical tenosynovitis scoring in a 6-month follow-up study.

METHODS

US and clinical assessments of the tendon sheaths of the clinically most affected hand and foot were performed at baseline, 3 and 6 months in 51 patients with RA. Tenosynovitis was assessed using the semi-quantitative scoring system (0-3) proposed by the OMERACT US group and a new quantitative US evaluation (0-100). A sum for US grey scale (GS), colour Doppler (CD) and pixel index (PI), respectively, was calculated for each patient. In 20 patients, intra- and inter-observer agreement was established between two independent investigators. A binary clinical tenosynovitis score was performed, calculating a sum score per patient.

RESULTS

The intra- and inter-observer agreements for US tenosynovitis assessments were very good at baseline and for change for GS and CD, but less good for PI. The smallest detectable change was 0.97 for GS, 0.93 for CD and 30.1 for PI. The sensitivity to change from month 0 to 6 was high for GS and CD, and slightly higher than for clinical tenosynovitis score and PI.

CONCLUSION

This study demonstrated an excellent intra- and inter-reader agreement between two investigators for the OMERACT US scoring system for tenosynovitis and a high ability to detect changes over time. Quantitative assessment by PI did not add further information.

Ultrasound-detected tenosynovitis independently associates with patient-reported flare in patients with rheumatoid arthritis in clinical remission: results from the observational study STARTER of the Italian Society for Rheumatology

OBJECTIVES

This study aimed to estimate the prevalence of US-detected tenosynovitis in RA patients in clinical remission and to explore its clinical correlates.

METHODS

A total of 427 RA patients in clinical remission were consecutively enrolled from 25 Italian rheumatology centres. Tenosynovitis and synovitis were scored by US grey scale (GS) and power Doppler (PD) semi-quantitative scoring systems at wrist and hand joints. Complete clinical assessment was performed by rheumatologists blinded to the US results. A flare questionnaire was used to assess unstable remission (primary outcome), HAQ for functional disability and radiographic erosions for damage (secondary outcomes). Cross-sectional relationships between the presence of each US finding and outcome variables are presented as odds ratios (ORs) and 95% CIs, both crude and adjusted for pre-specified confounders.

RESULTS

The prevalence of tenosynovitis in clinical remission was 52.5% (95% CI 0.48, 0.57) for GS and 22.7% (95% CI 0.19, 0.27) for PD, while the prevalence of synovitis was 71.6% (95% CI 0.67, 0.76) for GS and 42% (95% CI 0.37, 0.47) for PD. Among clinical correlates, PD tenosynovitis associated with lower remission duration and morning stiffness while PD synovitis did not. Only PD tenosynovitis showed a significant association with the flare questionnaire [OR 1.95 (95% CI 1.17, 3.26)]. No cross-sectional associations were found with the HAQ. The presence of radiographic erosions associated with GS and PD synovitis but not with tenosynovitis.

CONCLUSIONS

US-detected tenosynovitis is a frequent finding in RA patients in clinical remission and associates with unstable remission.

How does a cadaver model work for testing ultrasound diagnostic capability for rheumatic-like tendon damage?

To establish whether a cadaver model can serve as an effective surrogate for the detection of tendon damage characteristic of rheumatoid arthritis (RA). In addition, we evaluated intraobserver and interobserver agreement in the grading of RA-like tendon tears shown by US, as well as the concordance between the US findings and the surgically induced lesions in the cadaver model. RA-like tendon damage was surgically induced in the tibialis anterior tendon (TAT) and tibialis posterior tendon (TPT) of ten ankle/foot fresh-frozen cadaveric specimens. Of the 20 tendons examined, six were randomly assigned a surgically induced partial tear; six a complete tear; and eight left undamaged. Three rheumatologists, experts in musculoskeletal US, assessed from 1 to 5 the quality of US imaging of the cadaveric models on a Likert scale. Tendons were then categorized as having either no damage, (0); partial tear, (1); or complete tear (2). All 20 tendons were blindly and independently evaluated twice, over two rounds, by each of the three observers. Overall, technical performance was satisfactory for all items in the two rounds (all values over 2.9 in a Likert scale 1-5). Intraobserver and interobserver agreement for US grading of tendon damage was good (mean κ values 0.62 and 0.71, respectively), with greater reliability found in the TAT than the TPT. Concordance between US findings and experimental tendon lesions was acceptable (70-100 %), again greater for the TAT than for the TPT. A cadaver model with surgically created tendon damage can be useful in evaluating US metric properties of RA tendon lesions.

Aiming for a simpler early arthritis MRI protocol: can Gd contrast administration be eliminated?

PURPOSE

To evaluate whether intravenous gadolinium (Gd) contrast administration can be eliminated when evaluating synovitis and tenosynovitis in early arthritis patients, thereby decreasing imaging time, cost, and invasiveness.

MATERIALS AND METHODS

Wrist MRIs of 93 early arthritis patients were evaluated by two readers for synovitis of the radioulnar, radiocarpal, and intercarpal joints, according to the Rheumatoid Arthritis MRI Scoring method (RAMRIS), and for tenosynovitis in ten compartments. Scores of MRI images without Gd contrast enhancement were compared to scores obtained when evaluating all, including contrast-enhanced, MRI images as reference. Subsequently, a literature review and pooled analysis of data from the present and two previous studies were performed.

RESULTS

At the individual joint/tendon level, sensitivity to detect synovitis without Gd contrast was 91 % and 72 % for the two readers, respectively, with a specificity of 51 % and 81 %. For tenosynovitis, the sensitivity was 67 % and 54 %, respectively, with a specificity of 87 % and 91 %. Pooled data analysis revealed an overall sensitivity of 81 % and specificity of 50 % for evaluation of synovitis. Variations in tenosynovitis scoring systems hindered pooled analyses.

CONCLUSION

Eliminating Gd contrast administration resulted in low specificity for synovitis and low sensitivity for tenosynovitis, indicating that Gd contrast administration remains essential for an optimal assessment.

KEY POINTS

• Eliminating gadolinium contrast administration results in low specificity for synovitis • For tenosynovitis, sensitivity is low without gadolinium contrast administration • Gadolinium contrast administration remains essential for evaluating synovitis and tenosynovitis in early arthritis.

Focal hand lesions: review and radiological approach

Focal hand lesions are commonly encountered in clinical practice and are often benign. Magnetic resonance (MR) imaging is the imaging modality of choice in evaluating these lesions as it can accurately determine the nature of the lesion, enhancement pattern and exact location in relation to surrounding tissues. However, while MR features of various soft tissue lesions in the hand have been well described, it is often still difficult to differentiate between benign and malignant lesions. We review the MR imaging features of a variety of focal hand lesions presenting at our institution and propose a classification into "benign", "intermediate grade" (histologically benign but locally aggressive with potential for recurrence) and frankly "malignant" lesions based on MR findings. This aims to narrow down differential diagnoses and helps in further management of the lesion, preoperative planning and, in cases of primary malignancy, local staging. Teaching Points • Hand lesions are often benign and MR is essential as part of the workup. • MR features of various hand lesions are well described but are often non-specific. • Certain MR features may help for the diagnosis but histological examination is usually required. • We aim to classify hand lesions based on MR features such as margin, enhancement and bony involvement. • Classifying these lesions can help narrow down differential diagnoses and aid management.