Early-stage rheumatoid arthritis: diagnostic accuracy of MR imaging

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 Utility in Hand Surgery

Background: Magnetic resonance imaging (MRI) is frequently used in the diagnosis of upper extremity conditions. We hypothesize that the results often do not change treatment. The purpose of the present study was to prospectively assess the extent to which MRI findings alter patient management. Methods: Ten hand surgeons who were ordering an MRI (elbow or distal) completed a standardized questionnaire. Prior to obtaining the MRI, the surgeon recorded their pre-MRI diagnosis and recommended treatment if no MRI could be obtained. Following the MRI, the surgeon recorded their post-MRI diagnosis and ultimate treatment recommendation. Finally, the surgeon answered whether the MRI was helpful, and if so, how it helped guide their treatment. Descriptive statistics were performed. Results: One hundred eighty-seven MRIs were ordered. The most common reasons for ordering an MRI were the evaluation of presumed occult scaphoid fracture, ulnar wrist pain, metacarpophalangeal joint collateral ligament injury, and mass. The surgeon agreed with the radiologist's interpretation of the MRI in 88% of cases. Overall, surgeons found the MRI to be helpful in 92% of cases, and the recommended treatment changed as a result of the MRI findings in 19% (35/187) of patients. Of these 35 patients, 9 had a pre-MRI diagnosis that was concordant with the MRI findings, but the proposed management of the patient changed after the MRI. Conclusions: Hand surgeons infrequently change their treatment plan based on MRI findings. Given the importance of cost-efficient care, indications for use of MRI may need to be re-evaluated.

In vivo imaging of early stages of rheumatoid arthritis by α5β1-integrin-targeted positron emission tomography

Background

Rheumatoid arthritis (RA) is one of the most common rheumatic diseases. Joint inflammation and pathological growth of joint cartilage cause swollen and painful joints, which severely diminishes the patients’ life quality. There is no causal treatment. Symptomatic therapies should start as early as possible to take maximal effect. Hence, diagnostic procedures capable of detecting affected joints before the onset of clinical symptoms are highly desirable. We explored the value of PET imaging of integrin subtypes αvβ3 and α5β1 for early detection of RA foci in collagen-induced arthritis (CIA) mouse models.

Results

Development of RA in CIA mice was monitored by paw scoring, and αvβ3- and α5β1-integrin expression was quantified by μPET using ⁶⁸Ga-Avebetrin and ⁶⁸Ga-Aquibeprin. For consecutive sections of selected decalcified joints (knee, ankle), arthritic degeneration and integrin expression were assessed by MOVAT staining and β3/α5 immunohistochemistry (IHC), respectively. β3- and α5-IHC revealed elevated levels of both αvβ3- and α5β1-integrin in arthritic joints. Unlike αvβ3, α5β1 is strongly expressed in the proliferating synovial lining layer, which suggests that its presence is directly related to RA development. For mice with advanced RA (6 weeks after CIA), PET signals for α5β1-integrin were substantially stronger (> 300% of baseline) than that of αvβ3-integrin (< 200%). A longitudinal PET follow-up revealed that the manifestation of clinical symptoms of RA is preceded by upregulation of α5β1- but not of αvβ3-integrin.

Conclusion

α5β1-integrin PET could add a new functional imaging aspect to the portfolio of RA diagnostics because it appears to be a sensitive biomarker for early RA development. We suggest α5β1-integrin PET as a valuable tool to achieve a higher precision for early diagnosis of RA, including initial staging, monitoring of the disease course, and drug treatment, and for planning of radiosynoviorthesis (RSO).

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.

ERAMRS: a new MR scoring system for early rheumatoid arthritis of the wrist

PURPOSE

To (i) devise a new semi-quantitative scoring system known as Early Rheumatoid Arthritis Magnetic Resonance Score (ERAMRS) to assess inflammation of the wrist on magnetic resonance imaging in early rheumatoid arthritis and to (ii) test ERAMRS and other MR scoring systems against everyday used clinical scorings.

MATERIALS AND METHODS

One hundred six treatment-naïve patients (81 females, 25 males, mean age 53 ± 12 years) with early rheumatoid arthritis (ERA) underwent clinical/serological testing as well as 3-T MRI examination of the most symptomatic wrist. Clinical assessment included Disease Activity Score-28 and Health Assessment Questionnaire; erythrocyte sedimentation rate and C-reactive protein were measured. MR imaging data was scored in all patients using three devised MR semi-quantitative scoring systems, namely, the (a) ERAMRS system, (b) Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) system, and the (c) McQueen Score system.

RESULTS

Synovitis was present in 106 (100%), tenosynovitis in 98 (92%), and bone marrow edema in 84 (79%) of 106 ERA wrists. ERAMRS had the highest correlation with clinical disease activity scores (r = 0.476, p < 0.001) and serological parameters (r = 0.562, p < 0.001). RAMRIS system had the lowest correlation (r = 0.369, p < 0.001 for clinical disease activity; r = 0.436, p < 0.001 for serological parameters). RAMRIS synovitis subscore had a lower correlation than ERAMRS for clinical disease activity (r = 0.410, p < 0.001) and for serological parameters (r = 0.456, p < 0.001).

CONCLUSION

The ERAMRS system, designed to grade inflammation on wrist MRI in ERA, provided the best correlation with all clinical scoring systems and serological parameters, indicating its improved clinical relevance over other MR scoring systems.

KEY POINTS

• We devised a clinically relevant, easy-to-use semi-quantitative scoring system for scoring inflammation on MRI of the wrist in patients with early rheumatoid arthritis. • ERAMRS system showed better correlation with all clinical and serological assessment of inflammation in patients with early rheumatoid arthritis indicating its improved clinical relevance over other MR scoring systems.

Imaging in rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, and osteoarthritis: An international viewpoint on the current knowledge and future research priorities

Imaging is increasingly used in the routine management of rheumatic diseases as well as in the clinical trials of these disorders. This viewpoint, authored by a group of international imaging experts following two meetings dedicated to imaging in rheumatology, reports a consensus about the current knowledge and addresses where further research should be focused based on the views of the international imaging experts and discussion of the evidence with attending imaging practitioners. The goal was to maximize the potential of imaging to improve the clinical management of four rheumatic diseases. These rheumatic diseases include rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, and osteoarthritis.

Role of Contrast-enhanced Ultrasound in the Evaluation of Inflammatory Arthritis

Objective:

Contrast-enhanced ultrasound (CEUS) is a well-established imaging modality which has been put into clinical use in recent years with the development of second-generation contrast agent and imaging devices, and its applications in the assessment of inflammatory arthritis, such as rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, have provoked abundant discussion and researches among radiologists and rheumatologists. To summarize the achievements of clinical studies on CEUS in the application of arthritis, and to keep up with the latest progresses of the imaging technique, we reviewed the literature in recent years, hoping to establish the role of CEUS in joint diseases.

Data Sources:

PubMed and EMBASE.

Study Selection:

We searched the database with the conditions “contrast-enhanced ultrasound AND arthritis” with the time limitation of recent 10 years. Clinical studies applying CEUS in inflammatory arthritis and review articles about development of CEUS in joint diseases in English were selected.

Results:

As it is proved by most studies in recent years, by delineating microvasculature within the inflamed joints, CEUS can indicate early arthritis with high sensitivity and specificity. Moreover, the imaging of CEUS has been proved to be consistent with histopathological changes of inflammatory arthritis. Quantitative analysis of CEUS permits further evaluation of disease activity. CEUS also plays a significant role in the therapeutic monitoring of the disease, which has been backed up by a number of studies.

Conclusions:

CEUS may be a new choice for the rheumatologists to evaluate inflammatory arthritis, because of its low price, ability to provide dynamic pictures, and high sensitivity to angiogenesis. It can also be applied in disease classification and therapeutic monitoring. More studies about CEUS need to be done to set up the diagnostic standards.

Clinical utility of eco-color-power Doppler ultrasonography and contrast enhanced magnetic resonance imaging for interpretation and quantification of joint synovitis: a review

With the introduction of new biologics such as anti-TNF-alpha antibodies and other therapies in the treatment of inflammatory arthritis, capable of halting joint destruction and functional disability, there are new pressures on diagnostic and prognostic imaging. Early demonstration of pre-erosive inflammatory features and monitoring of the long-term effects of treatment are becoming increasingly important. Early detection of synovitis offers advantages in terms of allowing early instigation of therapy and may allow the identification of those patients displaying more aggressive disease who might benefit from early intervention with expensive DMARD therapy. Advanced imaging techniques such as ultrasound (US) and magnetic resonance imaging (MRI) have focussed on the demonstration and quantification of synovitis and allow early diagnosis of inflammatory arthropathies such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Synovitis represents a potential surrogate measure of disease activity that can be monitored using either MRI or US; the techniques have, generally, focused on monitoring synovial volume or quality as assessed by its vascularity. However to achieve these goals, standardisation and validation of US and MRI are required to ensure accurate diagnosis, reproducibility and reliability. Each modality has different strengths and weaknesses and levels of validation. This article aims to increase the awareness of radiologists and rheumatologists about this field and to encourage them to participate and contribute to the ongoing development of these modalities. Without this collaboration, it is unlikely that these modalities will reach their full potential in the field of rheumatological imaging. This review is in two parts. The first part addresses the role of US and colour or power Doppler sonography (PDUS) in the detection and monitoring of synovitis in inflammatory arthropathies. The second part will look at advanced MR imaging and Dynamic contrast-enhanced MRI techniques and in particular how they are applied to the monitoring of the disease process.

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.

Cost-Effectiveness Model for Evaluating New Diagnostic Tests in the Evaluation of Patients With Inflammatory Arthritis at Risk of Having Rheumatoid Arthritis

OBJECTIVE

New opportunities have emerged for early diagnosis with the arrival of new technologies that assess the impact of genomics, proteomics, metabolomics, and cytomics on rheumatoid arthritis (RA) risk. This early health technology assessment study assesses the short-term cost effectiveness of 4 add-on diagnostic tests in early inflammatory arthritis patients at risk of RA.

METHODS

We modeled 4 diagnostic add-on tests to the American College of Rheumatology/European League Against Rheumatism 2010 RA classification criteria, covering the first year after diagnosis, using Rotterdam Early Arthritis Cohort data. Sensitivity, specificity, and costs were assigned to the magnetic resonance imaging of hands and feet (sensitivity 0.90, specificity 0.60, cost €756), interleukin-6 (IL-6) serum level test (sensitivity 0.70, specificity 0.53, cost €50), B cell-related gene expression (sensitivity 0.60, specificity 0.90, cost €150), and gene assay for RA (sensitivity 0.40, specificity 0.85, cost €750), based on literature and expert opinion. Outcomes were evaluated using the unweighted diagnostic net benefit (UDNB) and the incremental cost-effectiveness ratio (ICER) in all patients (n = 552), intermediate-risk patients (n = 263), and seronegative patients (n = 329).

RESULTS

The highest UDNB was found when using the B cell assay in intermediate-risk patients (43%, ICER €5,314), while the IL-6 test in seronegative patients resulted in the lowest UDNB (-11.4%, ICER €7,650). If a threshold of €20,000 is applied, the B cell assay would be preferred over the other alternatives, with a 78% probability of being cost effective for intermediate-risk patients, 57% for all patients, and 73% for seronegative patients.

CONCLUSION

Diagnostic add-on tests favoring specificity over sensitivity with a headroom less than €370 per test are cost effective, with the largest diagnostic benefit occurring in intermediate-risk patients.

Imaging of regional pain syndromes; from syndromes to conditions using imaging?

Musculoskeletal regional pain syndromes often lead to patient referrals in general and rheumatological practice. Detailed history taking and clinical examination can in most cases reveal the cause for pain and direct the subsequent management of the conditions. Yet, when in doubt, imaging methods have to support the clinical assessment. This paper presents the underlying pathologies of the most frequently encountered regional pain syndromes and the role of musculoskeletal ultrasonography and magnetic resonance imaging in their visualization. It presents data, where available, on diagnostic accuracy and comparisons with gold standards. The article stresses the advantages and disadvantages of the analyzed imaging modalities and suggests the future research agenda.

Diagnosis and management of rheumatoid arthritis; What is the current role of established and new imaging techniques in clinical practice?

Ultrasound and magnetic resonance imaging (MRI) have become established imaging techniques for the management of rheumatoid arthritis. Several publications have pointed out the advantages of these techniques for a more complete evaluation of the inflammation and structural damage at joint level. Recently new imaging techniques as the positron emission tomography (PET) associated with computed tomography (CT) or MRI scan, and the optical imaging have been introduced in the panorama. This article presents the advantages and limitations of each imaging techniques in light with the recent publications.

Should modern imaging be part of remission criteria in rheumatoid arthritis?

With recent improvements in the treatment of rheumatoid arthritis (RA), remission has become an achievable goal for a large proportion of RA patients, and remission is now a defined target in current RA guidelines. However, studies have shown that progression of radiographic joint damage may occur in clinical remission, regardless of the choice of remission definition. Sub-clinical inflammation detected by modern imaging techniques such as ultrasonography and magnetic resonance imaging is present in the majority of patients in clinical remission, and is associated with progressive joint damage and disease activity flare in these patients. This chapter aims to assess the importance of imaging findings in RA patients in clinical remission and to discuss the possible role of modern imaging in future remission criteria.

Current perspectives on the advantages of 3-T MR imaging of the wrist

The use of 3-T magnetic resonance (MR) imaging systems with improved coil designs and high-resolution MR imaging sequences allows visualization of the musculoskeletal anatomy in exquisite detail and accurate characterization of abnormalities both in soft tissues and in bone. Current high-field-strength MR systems offer particular advantages for diagnostic imaging of the small joints of the extremities, especially the wrists, where multiple overlapping soft-tissue structures may be visually inseparable at lower field strengths because of limited contrast resolution. Diagnostic accuracy obtained with 3-T MR imaging of the wrist performed with an acquisition protocol that includes three-dimensional and proton density-weighted imaging sequences is nearly commensurate with that obtained with MR arthrography. Abnormalities of the ligaments, tendons, cartilage, nerves, blood vessels, and bone are clearly depicted, allowing accurate characterization of perforations, tears, and fractures, as well as various soft-tissue and intraosseous lesions (eg, ganglion cysts), vascular malformations, aneurysms, and neuropathies.

Spectrum of synovial pathologies: a pictorial assay

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

MR imaging assessment of inflammatory, crystalline-induced, and infectious arthritides

The role of magnetic resonance imaging in evaluating patients with inflammatory arthritides has evolved with the recent introduction of drugs capable of modifying disease activity and natural history. In conditions like rheumatoid arthritis, active synovitis and bone marrow inflammation precede and predict bone and cartilage erosion. These imaging findings identify patients who can be treated early and aggressively to prevent future morbidity. Similarly, in gout and other crystalline disorders, specific diagnosis aided by imaging may lead to earlier medical and surgical management. Infected joints need the most rapid identification to institute immediate therapy and prevent irreversible cartilage destruction.

Role of magnetic resonance imaging in the diagnosis and prognosis of rheumatoid arthritis

OBJECTIVE

To systematically evaluate the literature addressing the role of magnetic resonance imaging (MRI) in the diagnosis and prognosis of early undifferentiated inflammatory arthritis and rheumatoid arthritis (RA).

METHODS

We performed a systematic literature review of the performance characteristics of MRI for diagnosing and prognosticating RA. We searched Ovid, supplementing this with manual searches of bibliographies, journals, meeting proceedings, and the ClinicalTrials.gov web site. To identify diagnostic studies, we included studies of any duration that prospectively examined whether MRI findings predicted RA diagnosis and reported adequate information to calculate sensitivity and specificity. To identify prognostic studies, we included prospective studies with at least a 12-month followup period that measured both baseline MRI findings and clinical and/or radiographic outcomes.

RESULTS

For diagnostic studies (n = 11), sensitivity and specificity of MRI findings for RA diagnosis ranged from 20-100% and 0-100%, respectively, depending upon the criteria used. Diagnostic performance of MRI improved when lower-quality studies or studies with longer disease duration were excluded. For prognostic studies (n = 17), MRI findings did not predict clinical remission, and the ability to predict radiographic progression varied significantly (range 18-100% for sensitivity and 5.9-97% for specificity). Restricting the analysis to specific MRI findings or earlier disease improved MRI prognostic performance. The only prognostic study reporting 100% of a priori quality criteria found MRI bone edema to be the strongest predictor of radiographic progression.

CONCLUSION

Data evaluating MRI for the diagnosis and prognosis of early RA are currently inadequate to justify widespread use of this technology for these purposes, although MRI bone edema may be predictive of progression in certain RA populations.

First assessment of three-dimensional quantitative photoacoustic tomography for in vivo detection of osteoarthritis in the finger joints

PURPOSE

The purpose of this pilot clinical study is to assess three-dimensional (3-D) quantitative photoacoustic tomography (qPAT) for in vivo detection of osteoarthritis (OA) in the finger joints.

METHODS

All subject data were handled in compliance with the rules and regulations concerning the privacy and security of protected health information under HIPAA. Seven female subjects (two OA patients and five healthy controls) entered the study and their distal interphalangeal (DIP) joints were examined by a 3-D photoacoustic scanner. 3-D optical absorption coefficient images of all the photoacoustically examined joints were recovered using a 3-D qPAT reconstruction algorithm.

RESULTS

The recovered quantitative photoacoustic images revealed obvious difference in the optical absorption coefficient of the joint cavity (cartilage and synovial fluid) between the OA and healthy joints. Quantitative analysis of the joints also indicated an apparent difference in the recovered joint spacing between the OA and healthy subjects.

CONCLUSION

This initial clinical evaluation suggests that it is feasible to detect osteoarthritis in the finger joints with our 3-D qPAT approach, which has paved the way to further statistically evaluate the diagnostic performance of the 3-D qPAT approach in comparison with radiography or magnetic resonance imaging (MRI) on a sample of hand osteoarthritis.

Longitudinal MRI follow-up of rheumatoid arthritis in the temporomandibular joint: importance of synovial proliferation as an early-stage sign

This article describes longitudinal magnetic resonance imaging (MRI) observations in a patient with rheumatoid arthritis of the temporomandibular joint. The characteristic findings included marked synovial proliferation, which was observed before the onset of severe bone destruction. MRI is considered to provide valuable information for the early detection of rheumatoid arthritis of the temporomandibular joint.

Magnetic Resonance Imaging of the Rheumatic Foot According to the RAMRIS System Is Reliable

Objective.

In rheumatology, magnetic resonance imaging (MRI) is predominantly applied in the assessment and outcome measurement of rheumatoid arthritis (RA) in hands and wrists, leading to the development of the RAMRIS (RA-MRI-Scoring) system. It was initiated by the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT). The RAMRIS system has not been applied widely in the measurement of feet. We investigated the interreader and intrareader agreement of the RAMRIS scoring system in the assessment of feet in RA.

Methods.

Twenty-nine patients with RA who had radiological damage and/or arthritis underwent MRI. Two experienced readers independently read both complete sets. One reader read 6 random sets after the initial session, in order to assess the intrareader agreement. For evaluation of the intrareader and interreader reliability, quadratic-weighted κ scores were calculated per joint and lesion.

Results.

For the forefeet, interreader scores were excellent, ranging from 0.77 (bone edema) to 0.95 (bone erosion). Hindfoot interreader agreement scores were highest for erosion (0.90) and synovitis global score (0.88), but edema and synovial thickness agreement were also acceptable (0.83 and 0.86). Intrareader scores were on the whole slightly lower, but excellent.

Conclusion.

Reliability (interreader and intrareader agreement) in the assessment of the rheumatoid foot according to the RAMRIS method is excellent.

Early rheumatoid arthritis-do we really know what it means? Consistency and distribution of MRI findings according to different definitions for early rheumatoid arthritis

This study aims to characterize patients with early rheumatoid arthritis (RA) based on different definitions of early RA (disease duration, fulfillment of the American College of Rheumatology (ACR) criteria), and to determine whether these different definitions affect magnetic resonance imaging (MRI) findings of the hand. A cohort of 58 patients with early RA previously described was re-evaluated. There were 43 women and 15 men with a median age of 49 years, a disease duration of less than 2 years, and negative radiographs who were followed up for 6-41 months. MR images of the hand and wrist of these patients were retrospectively evaluated for the presence of synovitis, erosions, and tenosynovitis. The presence and distribution of these MRI findings were analyzed in three groups: fulfillment of 1987-ACR criteria, 6-month disease duration, and 12-month disease duration. Median disease duration was 11 months (range 1-24 months). Thirty patients (52%) fulfilled the ACR criteria. More patients fulfilling ACR criteria had MCP erosions and carpal synovitis compared with those not fulfilling the criteria; however, the difference was not significant. No significant difference was seen in the prevalence of synovitis, tenosynovitis, or erosions between the three groups. Patients with early RA of 2-years duration and negative hand X-ray findings are a homogenous group, regarding their MRI findings.

MRI for the assessment and monitoring of RA--what can it tell us?

The past 15 years has seen an exponential rise in the use of MRI for the assessment of rheumatoid arthritis (RA). In this Perspectives article, we review the current and potential future role of MRI in the diagnosis, prognosis and monitoring of RA. We also review the impact of MRI research on the understanding of disease mechanisms. In our view, the pivotal role of synovitis in RA and its predilection for sonographically accessible joints makes it likely that MRI will be used diagnostically in joints that are inaccessible to ultrasonography or where the differential diagnosis is unclear. Additionally, MRI will probably assume an even more prominent role in clinical trials where the aim of therapy is the complete ablation of synovitis. Given the ever-increasing sophistication of MRI, we anticipate that it will continue to be a key research tool in the coming years.

Multinational evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis: integrating systematic literature research and expert opinion of a broad international panel of rheumatologists in the 3E Initiative

Objective

To develop evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis (UPIA).

Methods

697 rheumatologists from 17 countries participated in the 3E (Evidence, Expertise, Exchange) Initiative of 2008–9 consisting of three separate rounds of discussions and modified Delphi votes. In the first round 10 clinical questions were selected. A bibliographic team systematically searched Medline, Embase, the Cochrane Library and ACR/EULAR 2007–2008 meeting abstracts. Relevant articles were reviewed for quality assessment, data extraction and synthesis. In the second round each country elaborated a set of national recommendations. Finally, multinational recommendations were formulated and agreement among the participants and the potential impact on their clinical practice was assessed.

Results

A total of 39 756 references were identified, of which 250 were systematically reviewed. Ten multinational key recommendations about the investigation and follow-up of UPIA were formulated. One recommendation addressed differential diagnosis and investigations prior to establishing the operational diagnosis of UPIA, seven recommendations related to the diagnostic and prognostic value of clinical and laboratory assessments in established UPIA (history and physical examination, acute phase reactants, autoantibodies, radiographs, MRI and ultrasound, genetic markers and synovial biopsy), one recommendation highlighted predictors of persistence (chronicity) and the final recommendation addressed monitoring of clinical disease activity in UPIA.

Conclusions

Ten recommendations on how to investigate and follow-up UPIA in the clinical setting were developed. They are evidence-based and supported by a large panel of rheumatologists, thus enhancing their validity and practical use.

Low‐field MRI for assessing synovitis in patients with rheumatoid arthritis. Impact of Gd‐DTPA dose on synovitis scoring

OBJECTIVE

To investigate the impact of a double dose compared to a single dose of contrast material in low-field magnetic resonance imaging (MRI) on semi-quantitative scoring of synovitis in patients with rheumatoid arthritis (RA).

METHODS

This prospective study included 38 RA patients (23 women and 15 men, mean age 51 years). All patients underwent low-field MRI of the hand before administration of contrast medium, after intravenous injection of 0.1 mmol/kg gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA), and after another dose of 0.1 mmol/kg Gd-DTPA. Two readers (A and B) blinded to dosage independently scored the single dose and double dose image sets for synovitis according to outcome measures in rheumatology (OMERACT) recommendations. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were also calculated for each set.

RESULTS

149 metacarpophalangeal (MCP) joints were evaluated. There was good inter-reader agreement for each of the two sets (intra-class correlation coefficient of 0.75 for the single dose set and 0.83 for the double dose). Median CNR and SNR values were 5.4 and 15.9, respectively, for the single dose set and 8.5 and 16.6, respectively, for the double dose set (p<0.0001). Single dose set mean synovitis scores were 1.7 and 1.6 for readers A and B, respectively. Double dose set scores were 1.9 and 2.0, respectively. Thus, higher synovitis scores were recorded for the double dose sets than the single dose sets (p<0.005).

CONCLUSION

In low-field MRI, when evaluating RA, the dose of the contrast material influences synovitis scoring. Therefore, dosage of contrast material should be taken into consideration when using extremity dedicated low-field MRI.

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

OBJECTIVE

To evaluate the potential of MRI of finger and wrist joints for diagnosing early RA. MRI was evaluated as a stand-alone tool and in combination with ACR criteria and serum markers such as RF.

METHODS

Ninety-nine patients (31 men, 68 women; median age 46 years) with unspecified arthritis or suspected RA and negative X-ray findings were included. MR images of the hand and wrist of these patients were retrospectively evaluated for the presence of synovitis, erosions and tenosynovitis. The clinical diagnosis (early RA or non-RA) was made by a rheumatologist after clinical follow-up for 6-41 months. Clinical and laboratory data were collected from all patients.

RESULTS

Fifty-eight patients had a clinical diagnosis of RA and 41 were diagnosed as non-RA. Step-wise logistic regression of all MR parameters evaluated identified tenosynovitis of the flexor tendons to be the most powerful predictor of early RA (sensitivity = 60%, specificity = 73%). Including ACR criteria in the analysis, positive serum RF and tenosynovitis were the strongest predictors of early RA (sensitivity = 83%, specificity = 63%). When serum anti-cyclic citrullinated peptides (CCP), ANA and CRP were included as additional parameters, anti-CCP and flexor tenosynovitis were the strongest predictors of early RA (sensitivity = 79%, specificity = 73%).

CONCLUSIONS

Flexor tenosynovitis diagnosed by MRI of the hand is a strong predictor of early RA. Combining flexor tenosynovitis on MRI with positive serum anti-CCP or positive RF is an even stronger predictor of early RA.

Overview of imaging in inflammatory arthritis

Whether magnetic resonance imaging (MRI) or ultrasound (US) are chosen for the purposes of musculoskeletal interrogation depends upon a variety of factors ranging from the anatomy targeted to cost considerations and the time of acquisition. Newer technologies such as higher-strength MRI or 3D-US promise to help overcome some of the disadvantages of each option. Improving technical proficiency is the thrust of efforts to support more widespread application of sonographic assessment in various clinical arenas. Finally, these technologies offer the opportunity to diagnose inflammatory conditions at early stages of their disease progression.

Arthroscopic synovectomy in rheumatoid arthritis of wrist

The wrist is the most commonly involved region of the upper extremity in rheumatoid arthritis (RA). Because the wrist joint becomes involved early during the disease course and its involvement rapidly progresses, and because the disabilities associated with progressive RA are significant, early and adequate treatment must be introduced to prevent disease progression. Various treatment methods can be employed to treat RA wrists based on radiological and clinical findings. Arthroscopic synovectomy is recommended for pain relief and functional recovery in early stage RA, and is also helpful in advanced staged RA with Larsen stage III. However, arthroscopic synovectomy is not recommended as an effective method of treatment for all patients with advanced radiographic changes. Nevertheless, arthroscopic synovectomy may delay the need for complex surgery, such as wrist arthrodesis or total wrist arthroplasty in selective cases. Although arthroscopic synovectomy of the wrist cannot improve grip strength or range of motion, it can reduce wrist pain and improve function, and thus facilitate return to work.

[Macrophage specific MRI imaging for antigen induced arthritides. A potential new strategy for the diagnosis of rheumatoid arthritis]

PURPOSE

The present work describes the potential of iron oxides for the detection of macrophages in synovitis in experimental, antigen-induced arthritis.

METHODS

The pivotal role of macrophages in rheumatoid arthritis (RA) in humans and in antigen-induced arthritis (AIA) in animal models is discussed. The latter appear to be very similar in many aspects to the human RA. We show the potential for iron oxide-enhanced magnetic resonance imaging (MRI) to determine the macrophage content in the arthritic synovial membranes. The results of our own research, as well as those of other research groups, are presented and discussed.

RESULTS

MRI after the intravenous (i.v.) administration of iron oxides enables the depiction of macrophage content in arthritic synovial membranes in AIA through the effects of the intracellular compartmentalisation of iron oxide particles. These effects can be demonstrated in 24-h delayed images after i.v. contrast application, on T2-weighted spin-echo or turbo-spin-echo sequences, and especially on T2*-weighted gradient-echo sequences. The signal effects are not only apparent in high field strength (4.7 Tesla) but also on 1.5 Tesla clinical scanners.

CONCLUSIONS AND PERSPECTIVES

The use of iron oxides enables the determination of the macrophage content in synovitis in animals with AIA. This parameter represents a potential marker to determine disease activity, and possibly represents a marker to evaluate the effectiveness of specific therapies in human RA. Current knowledge of iron oxide-enhanced MRI is limited to animal models. The clinical evaluation of this new method in patients with RA has not yet been performed. However, based on the considerations presented here, significant progress in the diagnostic work-up of RA can be expected.

The accuracy of magnetic resonance imaging of the hands and feet in the diagnosis of early rheumatoid arthritis

OBJECTIVE

To analyze MRI findings of early RA in the hand and foot joints and to determine any discrepancies between MRI findings in the hands and feet.

METHODS

Twenty one patients who fulfilled the 1987 American College of Rheumatology (ACR) criteria for the diagnosis of RA at the onset underwent MRI of both hands and feet.

RESULTS

In 18 out of 21 patients, rheumatoid changes were observed in the hand and foot joints. However, rheumatoid changes were observed only in the hand joints of the three remaining patients. MRI revealed pathologic findings suggested RA in the hands of 21 of 21 patients. In the feet, MRI findings suggested RA in 18 of 21 patients. Bone erosions were seen in the hands of 14 patients (67%). Observers found as many bony changes in the hands as in the foot joints. MRI detected active synovitis in 17 patients (81%) in the hands and in 15 patients (71%) in the feet. MRI findings suggested bone edema in the hand and foot joints in 14 (63%) and 11 patients (52%), respectively. There was no significant difference between the MCP and MTP joints with respect to RA-based changes obtained in the MRI (p>0.05).

CONCLUSION

Evidence of foot involvement is a frequent occurrence in early RA.

High-resolution MRI of the wrist and finger joints in patients with rheumatoid arthritis: comparison of 1.5 Tesla and 3.0 Tesla

The goal of this study was to compare magnetic resonance (MR) image quality at different field strengths for evaluating lesions in wrist and finger joints of patients with rheumatoid arthritis (RA) in order to determine whether the higher field strength provides diagnostic gain. The hand mainly affected in 17 RA patients was examined at 1.5 Tesla (T) and 3.0 T with comparable MR imaging (MRI) protocols. MR images were reviewed twice by two experienced radiologists using the Rheumatoid Arthritis MRI Scoring System (RAMRIS) of the OMERACT (Outcome Measures in Rheumatoid Arthritis Clinical Trials) group. Image quality was rated on a five-point scale using Friedmann's test and Kendall's W-test for statistical analysis. Image comparison revealed better image quality at higher field strength. Image quality of T1-weighted images was rated 14-22% better at 3.0 T compared with 1.5 T by both readers. Moreover, the rating for the T2-weighted-images acquired at 3.0 T was one point better in the five-point scale used. Inter-reader correlation for image quality, bone erosions/defects, edema and synovitis ranged between 0.6 and 0.9 at 3.0 T and between 0.6 and 0.8 at 1.5 T. Intra-reader correlation for these parameters was high at 0.8-1.0. MRI image quality of RA hands is superior at 3.0 T, while an acceptable image quality is achieved at 1.5 T, which improves the evaluation of extent of bone edema, synovitis and identification of small bone erosions.

Optimized System Design and Construction of a Compact Whole-hand Scanner for Diagnosis of Rheumatoid Arthritis

We have developed a compact magnetic resonance (MR) imaging scanner with permanent magnet, gradient coil set, and radiofrequency (RF) coils optimized for whole-hand examination for the diagnosis of rheumatoid arthritis (RA). The system weighs about 600 kg, and installation space is 2 m(2), excluding the shield room. Hand examinations of normal volunteers and patients with RA were performed using a 3D T(1)-weighted gradient-echo (GRE) sequence and short T(I) inversion recovery 3D fast spin-echo (STIR-3DFSE) sequence, and anatomical structures and various lesions of the hand caused by RA were clearly visualized in a 16-min examination. It was concluded that the system could be used for diagnosis of RA in even a small clinic.

Computerized digital imaging techniques provided by digital X-ray radiogrammetry as new diagnostic tool in rheumatoid arthritis

PURPOSE

Our study evaluates digital x-ray radiogrammetry (DXR) and Radiogrammetry Kit (RK) as a new diagnostic method for the measurement of disease-related osteoporosis including quantification of joint space narrowing dependent on the severity of rheumatoid arthritis (RA).

MATERIALS AND METHODS

A total of 172 unselected patients with RA underwent computerized measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as a semiautomated measurement of joint space distances at the metacarpal-phalangeal articulation (JSD-MCP 2-5), both were analyzed from plain radiographs of the nondominant hand.

RESULTS

Correlations between DXR-BMD and DXR-MCI vs. parameters of RK were all significant (0.34 < R < 0.61; p < 0.01). An expected negative association was observed between RK parameters and the different scoring methods (-0.27 < R < -0.59). The maximum relative decrease in BMD vs. MCI as measured by DXR between the highest and lowest RA severity group was -27.7% vs. -27.5% (p < 0.01) for the modified Larsen Score, whereas the minimal value of relative DXR-BMD and DXR-MCI reduction could be documented for the Sharp Erosion Score (-20.8% vs. -26.8%; p < 0.01). The relative reduction of mean JSD-MCP using RK significantly varied from -25.0% (Sharp Erosion Score) to -41.2% (modified Larsen Score). In addition, an excellent reproducibility of DXR and RK could be verified.

CONCLUSION

DXR in combination with RK could be a promising, widely available diagnostic tool to supplement the different scoring methods of RA with quantitative data, allowing an earlier and improved diagnosis and more precision in determining disease progression.

Periarticular Bone Findings in Rheumatoid Arthritis: T2-Weighted Versus Contrast-Enhanced T1-Weighted MRI

OBJECTIVE

The purpose of this study was to establish the relative predictive value of T2-weighted and contrast-enhanced T1-weighted MRI techniques for bone erosions that are evident on CT. Because it is known that MRI depicts abnormalities in the periarticular bone of patients with rheumatoid arthritis, we wanted to compare the outcomes of T2-weighted versus contrast-enhanced T1-weighted MRI techniques.

MATERIALS AND METHODS

Eleven patients with rheumatoid arthritis underwent CT imaging of their most affected wrist. Fast spin-echo T2-weighted MR images were then acquired with spectral fat saturation. Enhanced T1-weighted spin-echo images acquired before and after IV administration of gadopentetate dimeglumine were used to determine the percent enhancement. Imaging examinations were scored for 15 anatomic zones. The CT score was based on cortical bone erosion. The MR score was based on periarticular bone marrow signal alteration.

RESULTS

Both T2-weighted MR images with spectral fat saturation and enhanced T1-weighted images were concordant for the presence or absence of bone abnormalities in 122 of 165 zones (74%). Of the 43 zones that were discordant for an abnormality by the two MR techniques, the T2-weighted images were positive in five zones, and enhanced T1-weighted images were positive in 38 zones (p < 0.001). Of the 43 zones that were discordant by the two MR techniques, enhanced T1-weighted images were concordant with CT in 20 zones, whereas the T2-weighted images were concordant with CT in 23 zones (p = 0.76). A greater proportion of lesions detected by the T2-weighted images were "edema-like" signal patterns.

CONCLUSION

In rheumatoid arthritis, contrast-enhanced T1-weighted MRI depicts more periarticular bone abnormalities than fat-suppressed T2-weighted MRI. These MR techniques are equally predictive of frank, erosive disease that is evident on CT.

Low-field compact magnetic resonance imaging system for the hand and wrist in rheumatoid arthritis

PURPOSE

To investigate the feasibility of an originally developed compact MRI system for evaluating rheumatoid arthritis (RA), and determine its advantages and disadvantages as an imaging modality for evaluating RA.

MATERIALS AND METHODS

We prospectively studied 13 healthy controls with no clinical symptoms of arthritis, and 13 patients with hand and wrist pains (including pain from RA) with a 0.2 T permanent-magnet compact MR imager. All MR images were obtained while the subjects were in a sitting position. Coronal three-dimensional spin-echo T1-weighted images and coronal two-dimensional short tau inversion recovery (STIR) images were obtained with image matrix = 256 x 128 and field of view (FOV) = 20.48 cm. Plain radiograph findings and MRI findings of patients were compared.

RESULTS

In three of the patients with suspected early RA (N = 7), early RA was evaluated based on STIR images. All RA patients showed morphologic or signal intensity changes that allowed an evaluation of RA from MR findings. Four of five RA patients showed high signal intensity on STIR images in the wrist, proximal interphalangeal (PIP) joint, or metacarpophalangeal (MCP) joint that suggested synovitis. Multiple erosions in the hand and wrist were seen in four RA patients, with low signal intensity on T1-weighted images.

CONCLUSION

RA was correctly evaluated, and early RA could be identified with the compact MRI system. However, the current system has limitations, such as the nonselective STIR sequence used and magnetic field inhomogeneity.

MR Imaging: Arthropathies and Infectious Conditions of the Elbow, Wrist, and Hand

The superior soft tissue contrast and multiplanar capability of MR imaging has contributed to earlier diagnosis and implementation of effective treatment for a variety of arthropathies and infectious conditions of the elbow, wrist, and hand. Because of overlapping clinical signs and symptoms, MR imaging plays an important role in delineating the features and staging of each of these conditions. This article discusses the seropositive and seronegative inflammatory arthropathies, with emphasis on early detection and surveillance, as well as gout, synovial osteochondromatosis, pigmented villonodular synovitis, tenosynovitis, and de Quervain's tenosynovitis. Certain noninflammatory arthritides and infectious conditions are also reviewed.

Ultrasmall supraparamagnetic iron oxide-enhanced magnetic resonance imaging of antigen-induced arthritis: a comparative study between SHU 555 C, ferumoxtran-10, and ferumoxytol

OBJECTIVES

We sought to compare the ability of 3 ultrasmall superparamagnetic iron oxides (USPIOs) to detect and characterize antigen-induced arthritis with MR imaging.

MATERIALS AND METHODS

A monoarthritis was induced in the right knee of 18 rats. The left knee served as a normal control. Knees underwent magnetic resonance (MR) imaging before, up to 2 hours, and 24 hours after injection (p.i.) of 200 mumol Fe/kg SHU 555 C (n= 6), ferumoxtran-10 (n = 6), or ferumoxytol (n = 6), using T2-2D-SE 100/20,40,60,80/90 (TR/TE/flipangle), T2*-3D-spoiled gradient recalled (SPGR) 100/15/38, and T1-3D-SPGR 50/1,7/60 sequences.

RESULTS

Quantitative signal to noise ratio and DeltaSI data of arthritic knees on T1- and T2*-weighted MR images showed no significant differences between the 3 USPIOs (P > 0.05). At 2 hours p.i., SNR and DeltaSI data were significantly increased from baseline on T1-weighted images and significantly decreased on T2*-weighted images (P < 0.001). At 24 hours p.i., the T1-enhancement returned to baseline, whereas the T2*-enhancement remained significantly elevated (P < 0.001). Immunostains demonstrated an USPIO compartmentalization in macrophages in the arthritic synovium.

CONCLUSIONS

Based on the relatively small number of animals in our study group, inflammation in antigen-induced arthritis can be equally detected and characterized with any of the three USPIOs evaluated.

MRI and musculoskeletal ultrasonography as diagnostic tools in early arthritis

Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disorder primarily affecting the synovium and is characterized by destruction of bone and cartilage. Early diagnosis and treatment of RA can improve disease outcomes substantially. Magnetic resonance imaging and musculoskeletal ultrasonography may facilitate early diagnosis and aid the targeting of intensive therapy. Magnetic resonance imaging and musculoskeletal ultrasonography also are able to monitor temporal changes in disease activity (ie, synovitis) and damage (ie, erosions). These imaging modalities are likely to be increasingly used in the management of early rheumatoid arthritis to ensure the best patient outcomes, although more work is required to determine their optimal roles.

Dynamic gadolinium-enhanced fat-suppressed T1-weighted MRI (chemical shift selective images) for remitting seronegative symmetrical synovitis with pitting edema

A 75-year-old man suddenly suffered from polyarthralgia and pitting edema in his distal extremities. Laboratory tests revealed inflammation, negative rheumatoid factor, and positive B7 human leukocyte antigen typing. Severe synovitis was observed in dynamic gadolinium-enhanced fat-suppressed (DGEFS) T1-weighted images of his right hand. Our diagnosis was remitting seronegative symmetrical synovitis with pitting edema (RS(3)PE syndrome). He responded dramatically to low-dose corticosteroids, after which his synovitis remarkably improved as observed with DGEFS imaging. DGEFS imaging is useful for distribution of synovitis in patients with RS(3)PE syndrome as well as assessing the efficacy of treatment.

Can magnetic resonance imaging differentiate undifferentiated arthritis?

A high sensitivity for the detection of inflammatory and destructive changes in inflammatory joint diseases makes magnetic resonance imaging potentially useful for assigning specific diagnoses, such as rheumatoid arthritis and psoriatic arthritis in arthritides, that remain undifferentiated after conventional clinical, biochemical and radiographic examinations. With recent data as the starting point, the present paper describes the current knowledge on magnetic resonance imaging in the differential diagnosis of undifferentiated arthritis.

MR Imaging Findings in Hands in Early Rheumatoid Arthritis: Comparison with Those in Systemic Lupus Erythematosus and Primary Sjögren Syndrome

PURPOSE

To evaluate prospectively the use of magnetic resonance (MR) imaging for differentiating true rheumatoid arthritis (RA) from systemic lupus erythematosus (SLE) or primary Sjögren syndrome in patients who have inflammatory polyarthralgia of the hands but no radiographic evidence of RA.

MATERIALS AND METHODS

This study had institutional review board approval, and patient informed consent was obtained. Twenty-eight patients (16 female and 12 male patients; mean age, 42 years) with early RA and 19 patients (18 female and one male patient; mean age, 46 years) with SLE (n = 14) or primary Sjögren syndrome (n = 5) underwent MR imaging of both hands. All patients had inflammatory polyarthralgia of the hands and no evidence of erosive changes on radiographs. Coronal T2-weighted short inversion time inversion-recovery, transverse T1-weighted spin-echo, transverse fat-suppressed gadolinium-enhanced T1-weighted spin-echo, and transverse gadolinium-enhanced three-dimensional gradient-echo MR images were obtained. The following MR imaging variables were assessed in the wrist and nonthumb metacarpophalangeal joints: synovitis, bone lesions (erosion, defect, and edema), and tenosynovitis. Synovitis and bone lesions were scored with the OMERACT RA-MRI scoring system. Findings in patients with RA and those without RA were compared by means of Mann-Whitney, chi2, and Fisher exact tests.

RESULTS

The only significant difference between the two groups in terms of individual scores for synovitis, bone lesions, and tenosynovitis was the more frequent presence of tenosynovitis of the right fourth extensor tendon in patients without RA (P = .04). There were no significant differences between patients with RA and those without RA in terms of global scores for synovitis, bone lesions, and tenosynovitis. However, bone marrow edema in the metacarpophalangeal joints was seen more frequently in patients with RA (P < .001).

CONCLUSION

It may be impossible to distinguish between patients with early RA and those without RA (ie, those with SLE or primary Sjögren syndrome) by means of MR imaging.

Magnetic resonance imaging of peripheral joints in rheumatic diseases

The need for better methods than the conventional clinical, biochemical and radiographical examinations in the management of inflammatory joint diseases is evident, since these methods are not sensitive or specific to early pathologies and subtle changes. Magnetic resonance imaging (MRI) offers improved sensitivity to early inflammatory and destructive changes in peripheral joints in rheumatoid arthritis (RA) and, even though less well documented, in other inflammatory joint diseases. Good evidence is available that MRI bone erosions represent true bone abnormalities and are predictors of radiographical outcome in RA. Similarly, there is solid evidence for MRI synovitis representing true synovial inflammation and being of considerable practical, clinical and radiological significance in RA. Describing the encouraging current knowledge regarding MRI for diagnosis, monitoring and prognosis, this chapter discusses the potential for the use of MRI in the clinical management of patients with suspected and diagnosed inflammatory joint diseases, as well as research priorities and clinical situations where the use of MRI could be suggested.

Optimised, low cost, low field dedicated extremity MRI is highly specific and sensitive for synovitis and bone erosions in rheumatoid arthritis wrist and finger joints: comparison with conventional high field MRI and radiography

OBJECTIVE

To evaluate a low field dedicated extremity MRI unit for detection of bone erosions, synovitis, and bone marrow oedema in wrist and metacarpophalangeal (MCP) joints, with a high field MRI unit as the standard reference.

METHODS

In 37 patients with RA and 28 healthy controls MRI of the wrist and 2nd-5th MCP joints was performed on a low field MRI unit (0.2 T Esaote Artoscan) and a high field MRI unit (1.0 T Siemens Impact) on 2 subsequent days. MRI was performed and evaluated according to OMERACT recommendations. Additionally, conventional x ray, clinical, and biochemical examinations were performed. In an initial low field MRI "sequence selection phase", based on a subset of 10 patients and 10 controls, sequences for comparison with high field MRI were selected.

RESULTS

With high field, spin echo MRI considered as the reference method, the sensitivity, specificity, and accuracy of low field 3D gradient echo MRI for erosions were 94%, 93%, 94%, while the corresponding values for x ray examination were 33%, 98%, and 83%. Sensitivity, specificity, and accuracy of low field MRI for synovitis were 90%, 96%, and 94%, and for bone marrow oedema 39%, 99%, and 95%. Intraclass correlation coefficients between low field and high field scores were 0.936 (p<0.005) for bone erosions and 0.923 (p<0.05) for synovitis.

CONCLUSION

Low field MRI provides high accuracy for detection and grading of erosions and synovitis, with high field MRI as the standard reference. For bone marrow oedema, specificity is high, but sensitivity only moderate. Low cost, patient compliant, low field dedicated extremity MRI provides similar information on bone erosions and synovitis as expensive high field MRI units.