Magnetic resonance imaging of wrist and finger joints in healthy subjects occasionally shows changes resembling erosions and synovitis as seen in rheumatoid arthritis

Automated quantification of wrist bone marrow oedema, pre- and post-treatment, in early rheumatoid arthritis

Objective

Bone inflammation (osteitis) in early RA (ERA) manifests as bone marrow oedema (BME) and precedes the development of bone erosion. In this prospective, single-centre study, we developed an automated post-processing pipeline for quantifying the severity of wrist BME on T2-weighted fat-suppressed MRI.

Methods

A total of 80 ERA patients [mean age 54 years (s.d. 12), 62 females] were enrolled at baseline and 49 (40 females) after 1 year of treatment. For automated bone segmentation, a framework based on a convolutional neural network (nnU-Net) was trained and validated (5-fold cross-validation) for 15 wrist bone areas at baseline in 60 ERA patients. For BME quantification, BME was identified by Gaussian mixture model clustering and thresholding. BME proportion (%) and relative BME intensity within each bone area were compared with visual semi-quantitative assessment of the RA MRI score (RAMRIS).

Results

For automated wrist bone area segmentation, overall bone Sørensen-Dice similarity coefficient was 0.91 (s.d. 0.02) compared with ground truth manual segmentation. High correlation (Pearson correlation coefficient r = 0.928, P < 0.001) between visual RAMRIS BME and automated BME proportion assessment was found. The automated BME proportion decreased after treatment, correlating highly (r = 0.852, P < 0.001) with reduction in the RAMRIS BME score.

Conclusion

The automated model developed had an excellent segmentation performance and reliable quantification of both the proportion and relative intensity of wrist BME in ERA patients, providing a more objective and efficient alternative to RAMRIS BME scoring.

Prevalence and distribution of ultrasound-detected hand synovial abnormalities in a middle-aged and older population

OBJECTIVE

Synovial abnormalities are modifiable targets for hand pain and osteoarthritis. We examined the prevalence and distribution of ultrasound-detected hand synovial abnormalities in a community-derived sample of older people in China.

METHODS

Within the Xiangya Osteoarthritis Study, a community-based study, we assessed synovial hypertrophy (SH), joint effusion, and Power Doppler signal (PDS) on all fingers and thumbs of both hands using standardized ultrasound examinations (score: 0-3). We assessed distribution patterns of SH and effusion using χ2-test and interrelationships of SH and effusion in different joints and hands by generalized estimating equations.

RESULTS

Among 3,623 participants (mean age: 64.4 years; women: 58.1%), prevalence of SH, effusion and PDS were 85.5%, 87.3% and 1.5%, respectively. Prevalence of SH, effusion and PDS increased with age, was higher in the right hand than in the left hand and was more common in proximal than in distal hand joints. SH and effusion often occurred in multiple joints (P < 0.001). SH in one joint was strongly associated with presence of SH in the same joint of the opposite hand (odds ratio [OR]= 6.60, 95% confidence interval [CI]: 6.19-7.03) followed by SH in other joints in the same row, (OR=5.70, 95%CI: 5.32-6.11), and then other joints in the same ray of the same hand (OR=1.49, 95%CI: 1.39-1.60). Similar patterns were observed for effusion.

CONCLUSION

Hand synovial abnormalities are common among older people, often affect multiple hand joints and present a unique pattern. These findings suggest both systemic and mechanical factors play roles in their occurrence.

Musculoskeletal involvement in systemic lupus erythematosus: a contrast-enhanced magnetic resonance imaging study in 107 subjects

OBJECTIVE

Joint involvement in SLE is the most frequent manifestation and shows a wide heterogeneity. It has not a valid classification and it is often underestimated. Subclinical inflammatory musculoskeletal involvement is not well known. We aim to describe the prevalence of joint and tendon involvement in hand and wrist of SLE patients, either with clinical arthritis, arthralgia or asymptomatic and compare it with healthy subjects using contrasted MRI.

METHODS

SLE patients fulfilling SLICC criteria were recruited and classified as follows: group (G) 1: hand/wrist arthritis, G2: hand/wrist arthralgia, G3: no hand/wrist symptoms. Jaccoud arthropathy, CCPa and RF positivity, hand OA or surgery were excluded. Healthy subjects (HS) were recruited as controls: G4. Contrasted MRI of non-dominant hand/wrist was performed. Images were evaluated following RAMRIS criteria extended to PIP, Tenosynovitis score for RA and peritendonitis from PsAMRIS. Groups were statistically compared.

RESULTS

A total of 107 subjects were recruited (G1: 31, G2:31, G3:21, G4:24). Any lesion: SLE patients 74.7%, HS 41.67%; P 0.002. Synovitis: G1: 64.52%, G2: 51.61%, G3: 45%, G4: 20.83%; P 0.013. Erosions: G1: 29.03%; G2: 54.84%, G3: 47.62%; G4: 25%; P 0.066. Bone marrow oedema: G1: 29.03%, G2: 22.58%, G3: 19.05%, G4: 0.0%; P 0.046. Tenosynovitis: G1: 38.71%; G2: 25.81%, G3: 14.29%, G4: 0.0%; P 0.005. Peritendonitis: G1: 12.90%; G2: 3.23%, G3: 0.0%, G4: 0.0%; P 0.07.

CONCLUSION

SLE patients have a high prevalence of inflammatory musculoskeletal alterations confirmed by contrasted MRI, even if asymptomatic. Not only tenosynovitis but peritendonitis is also present.

Lumbrical muscle enhancement on MRI and its association with rheumatoid arthritis

OBJECTIVE

To investigate the significance of lumbrical muscle enhancement (LME) on magnetic resonance imaging (MRI) in rheumatoid arthritis (RA).

MATERIALS AND METHODS

Blinded to the diagnoses, contrast-enhanced bilateral hand MRIs of patients with suspected early RA between 2014 and 2019 were reviewed by two observers for the presence and degree (weak/strong) of LME. The presence of other inflammatory findings was also noted. The patients were then stratified into RA (n = 41), control (n = 31), and other arthritides groups(n = 28) based on their final diagnoses in the hospital records within the following 12 months. Categorical variables were compared by chi-square test or Fisher's exact test. Differences among the groups were evaluated by one-way ANOVA or Kruskal-Wallis tests. When the p-value from the Kruskal-Wallis test was statistically significant, multiple comparison test was used to identify group differences. Correlations between LME and flexor tenosynovitis were evaluated by Spearman rank correlation test. The agreement between two observers was assessed by Cohen's Kappa (κ) statistic. P-value < 0.05 was considered as statistically significant.

RESULTS

There were 100 patients (88 females) with mean age of 47.2 ± 11.2. There were no significant differences for age or sex between groups (p = 0.17, p = 0.84, respectively). RA patients showed significantly more frequent (p < 0.001) and stronger LME (p = 0.001). There were no correlations between LME and flexor tenosynovitis (p > 0.05). Interrater agreement for the degree of LME on right and left sides was substantial (κ = 0.74, κ = 0.67, respectively).

CONCLUSION

RA patients demonstrated significantly more frequent and stronger LME with substantial interrater agreement. LME could constitute a subtle radiological clue for early RA.

Radiological assessment and surgical management of cervical spine involvement in patients with rheumatoid arthritis

The purpose of the present systematic review was to describe the diagnostic evaluation of rheumatoid arthritis in the cervical spine to provide a better understanding of the indications and options of surgical intervention. We performed a literature review of Pub-med, Embase, and Scopus database. Upon implementing specific inclusion and exclusion criteria, all eligible articles were identified. A total of 1878 patients with Rheumatoid Arthritis (RA) were evaluated for cervical spine involvement with plain radiographs. Atlantoaxial subluxation (AAS) ranged from 16.4 to 95.7% in plain radiographs while sub-axial subluxation ranged from 10 to 43.6% of cases. Anterior atlantodental interval (AADI) was found to between 2.5 mm and 4.61 mm in neutral and flexion position respectively, while Posterior Atlantodental Interval (PADI) was between 20.4 and 24.92 mm. 660 patients with RA had undergone an MRI. A pannus diagnosis ranged from 13.33 to 85.36% while spinal cord compression was reported in 0-13% of cases. When it comes to surgical outcomes, Atlanto-axial joint (AAJ) fusion success rates ranged from 45.16 to 100% of cases. Furthermore, the incidence of postoperative subluxation ranged from 0 to 77.7%. With regards to AADI it is evident that its value decreased in all studies. Furthermore, an improvement in Ranawat classification was variable between studies with a report improvement frequency by at least one class ranging from 0 to 54.5%. In conclusion, through careful radiographic and clinical evaluation, cervical spine involvement in patients with RA can be detected. Surgery is a valuable option for these patients and can lead to improvement in their symptoms.

RANKL-responsive epigenetic mechanism reprograms macrophages into bone-resorbing osteoclasts

Monocyte/macrophage lineage cells are highly plastic and can differentiate into various cells under different environmental stimuli. Bone-resorbing osteoclasts are derived from the monocyte/macrophage lineage in response to receptor activator of NF-κB ligand (RANKL). However, the epigenetic signature contributing to the fate commitment of monocyte/macrophage lineage differentiation into human osteoclasts is largely unknown. In this study, we identified RANKL-responsive human osteoclast-specific superenhancers (SEs) and SE-associated enhancer RNAs (SE-eRNAs) by integrating data obtained from ChIP-seq, ATAC-seq, nuclear RNA-seq and PRO-seq analyses. RANKL induced the formation of 200 SEs, which are large clusters of enhancers, while suppressing 148 SEs in macrophages. RANKL-responsive SEs were strongly correlated with genes in the osteoclastogenic program and were selectively increased in human osteoclasts but marginally presented in osteoblasts, CD4+ T cells, and CD34+ cells. In addition to the major transcription factors identified in osteoclasts, we found that BATF binding motifs were highly enriched in RANKL-responsive SEs. The depletion of BATF1/3 inhibited RANKL-induced osteoclast differentiation. Furthermore, we found increased chromatin accessibility in SE regions, where RNA polymerase II was significantly recruited to induce the extragenic transcription of SE-eRNAs, in human osteoclasts. Knocking down SE-eRNAs in the vicinity of the NFATc1 gene diminished the expression of NFATc1, a major regulator of osteoclasts, and osteoclast differentiation. Inhibiting BET proteins suppressed the formation of some RANKL-responsive SEs and NFATc1-associated SEs, and the expression of SE-eRNA:NFATc1. Moreover, SE-eRNA:NFATc1 was highly expressed in the synovial macrophages of rheumatoid arthritis patients exhibiting high-osteoclastogenic potential. Our genome-wide analysis revealed RANKL-inducible SEs and SE-eRNAs as osteoclast-specific signatures, which may contribute to the development of osteoclast-specific therapeutic interventions.

When and how should we use imaging in individuals at risk of rheumatoid arthritis?

In recent years rheumatologists have begun to shift focus from early rheumatoid arthritis (RA) to studying individuals at risk of developing the disease. It is now possible to use blood, clinical and imaging biomarkers to identify those at risk of progression before the onset of clinical synovitis. The use of imaging, in particular ultrasound (US) and magnetic resonance imaging (MRI), has become much more widespread in individuals at-risk of RA. Numerous studies have demonstrated that imaging can help us understand RA pathogenesis as well as identifying individuals at high risk of progression. In addition, imaging techniques are becoming more sophisticated with newer imaging modalities such as high-resolution peripheral quantitative computed tomography (HR-pQRCT), nuclear imaging and whole body-MRI (WB-MRI) starting to emerge. Imaging studies in at risk individuals are heterogeneous in nature due to the different at-risk populations, imaging modalities and protocols used. This review will explore the available imaging modalities and the rationale for their use in the main populations at risk of RA.

Rheumatoid Arthritis Relapse and Remission - Advancing Our Predictive Capability Using Modern Imaging

Clinical remission has become an achievable target for the majority of patients with rheumatoid arthritis, but subclinical inflammation as assessed by ultrasound and magnetic resonance imaging (MRI) has been demonstrated to be frequent in patients in clinical remission. Subclinical synovitis has been shown to be linked to both subsequent structural damage progression and a risk of flare, demonstrating that subclinical synovitis represents incomplete suppression of inflammation and questions whether it is appropriate only to use clinical composite scores as treatment target in clinical practice. Maintaining a state of remission has proven important as sustained clinical remission impacts long-term outcome regarding joint damage progression, physical function and quality of life. Treating subclinical inflammation has been attempted and has led to more frequent strict clinical remission and better physical function, but also to more adverse events. Thus, an overall benefit of incorporating imaging goals in treat-to-target strategies has not been documented. However, in patients in clinical remission on biological disease-modifying anti-rheumatic drugs, both ultrasound and MRI may aid in the clinical decision regarding whether drug tapering or even discontinuation should be attempted.

The Relationship Between Serum Angiogenic Factor Levels and Disease Activity in Rheumatoid Arthritis

Objectives

This study aims to evaluate the relationship between serum angiogenic factor levels and disease activity in patients with rheumatoid arthritis (RA) using both clinical and dynamic wrist magnetic resonance imaging (MRI) data.

Patients and methods

Simultaneous serum angiogenesis markers [vascular endothelial growth factor (VEGF), angiopoietin-1 (ANG1), ANG2, and tyrosine-protein kinase receptor for angiopoietin (Tie-2)] were studied in 40 patients with RA (13 males, 27 females; mean age 51.1±10.8 years; range, 23 to 69 years) and 20 healthy controls (11 males, 9 females; mean age 47.3±12.8 years; range, 29 to 69 years) and dynamic contrast-enhanced wrist MRI was performed in 40 RA patients and seven controls. Rate of early in 55th second (REE) and Relative enhancement (REt) values were calculated from the signal time curve values obtained from the analysis of images. In clinical assessment, duration of morning stiffness, patient pain assessment [visual analog scale (VAS)], physician and patient global assessments (VAS) were recorded. The number of tender joints and swollen joints were determined. Disease activity score 28 and Ritchie scores were calculated. Health assessment questionnaire was used for functional evaluation. Anti-cyclic citrullinated peptide, rheumatoid factor, erythrocyte sedimentation rate and high sensitive C-reactive protein analyses were performed.

Results

Serum VEGF, REE and REt values were significantly higher in RA patients than healthy controls (p=0.002, p=0.00, p=0.00, respectively). There was no significant correlation between serum angiogenesis markers and clinical parameters or REE and REt (p>0.05). VEGF value correlated positively with disease duration (p=0.024).

Conclusion

Serum VEGF was higher in RA patients. While its level was associated with disease duration, no significant correlation was found with disease activity. As a diagnostic test, dynamic contrast-enhanced MRI was a valuable method for showing disease activity.

Whole-body Magnetic Resonance Imaging in Psoriatic Arthritis, Rheumatoid Arthritis, and Healthy Controls: Interscan, Intrareader, and Interreader Agreement and Distribution of Lesions

Objective.

Whole-body MRI (WBMRI) is a promising technique for monitoring patients’ global disease activity in inflammatory joint diseases. The validation of WBMRI is limited; no studies have evaluated the test-retest agreement (interscan agreement) and only a few have assessed the intra- and interreader agreement. Therefore, we first examined the interscan agreement of WBMRI in patients with psoriatic arthritis (PsA), rheumatoid arthritis (RA), and healthy controls (HC); and second, we evaluated the intra- and interreader agreement and agreement with conventional hand MRI and determined the distribution of lesions.

Methods.

WBMRI was performed twice at a 1-week interval in 14 patients with PsA, 10 with RA, and 16 HC. Images were anonymized and read in pairs with unknown chronological order by experienced readers according to the Outcome Measures in Rheumatology (OMERACT) WBMRI, Canada-Denmark MRI, and the RA MRI scoring system (RAMRIS) and the PsA MRI scoring system (PsAMRIS). Ten image sets were reanonymized for assessment of intra- and interreader agreement. Agreement was calculated on lesion level by percentage exact agreement (PEA) and Cohen κ, and for sum scores by absolute agreement, single-measure intraclass correlation coefficient (ICC).

Results.

WBMRI of the spine and peripheral joints and entheses generally showed moderate to almost perfect interscan agreement with PEA ranging from 95% to 100%, κ 0.71–1.00, and ICC 0.95 to 1.00. Intra- and interreader data generally showed moderate to almost perfect agreement. Agreement with conventional MRI varied. More lesions were found in patients than in HC.

Conclusion.

WBMRI showed good interscan agreement, implying that repositioning of the patient between examinations does not markedly affect scoring of lesions. Intra- and interreader agreement were moderate to almost perfect.

Validity and diagnostic performance of fluorescence optical imaging measuring synovitis in hand osteoarthritis: baseline results from the Nor-Hand cohort

OBJECTIVE

Fluorescence optical imaging (FOI) demonstrates enhanced microcirculation in finger joints as a sign of inflammation. We wanted to assess the validity and diagnostic performance of FOI measuring synovitis in persons with hand OA, comparing it with magnetic resonance imaging (MRI)- and ultrasound-detected synovitis.

METHODS

Two hundred and twenty-one participants with hand OA underwent FOI and ultrasound (gray-scale synovitis and power Doppler activity) of the bilateral hands and contrast-enhanced MRI examination of the dominant hand. Fifteen joints in each hand were scored on semi-quantitative scales (grade 0-3) for all modalities. Four FOI images were evaluated: one composite image (Prima Vista Mode (PVM)) and three images representing phases of fluorescent dye distribution. Spearman's correlation coefficients were calculated between sum scores of FOI, MRI, and ultrasound. Sensitivity, specificity, and area under the curve (AUC) were calculated for FOI using MRI or ultrasound as reference.

RESULTS

FOI did not demonstrate enhancement in the thumb base, and the joint was excluded from further analyses. FOI sum scores showed poor to fair correlations with MRI (rho 0.01-0.24) and GS synovitis sum scores (rho 0.12-0.25). None of the FOI images demonstrated both good sensitivity and specificity, and the AUC ranged from 0.50-0.61 and 0.51-0.63 with MRI and GS synovitis as reference, respectively. FOI demonstrated similar diagnostic performance with PD activity and GS synovitis as reference.

CONCLUSION

FOI enhancement correlated poorly with synovitis assessed by more established imaging modalities, questioning the value of FOI for the evaluation of synovitis in hand OA.

Assessment of structural damage progression in established rheumatoid arthritis by conventional radiography, computed tomography, and magnetic resonance imaging

Structural damage progression in patients with established rheumatoid arthritis (RA) has traditionally been assessed by conventional radiography (CR), which has proven its value in clinical practice and clinical trials over the past decades. The most prominent abnormalities visualized by CR in RA patients are erosions as a consequence of bone destruction and joint space narrowing (JSN) as a consequence of cartilage damage. Several validated scoring systems to quantify the structural joint damage and progression herein are available. Computed tomography and magnetic resonance imaging are newer, more sensitive methods for detection and monitoring of structural joint damage. A validated scoring system for magnetic resonance imaging of the hands and wrists exists, while no consensus has been reached on a scoring system for computed tomography. Structural damage identified by either CR or magnetic resonance imaging predicts a poorer disease course in patients with both early and established rheumatoid arthritis.

Exploring contrast-enhanced MRI findings of the clinically non-inflamed symptomatic pediatric wrist

BACKGROUND

Knowledge of the synovial and tenosynovial appearance of the clinically non-arthritic symptomatic juvenile wrist using contrast-enhanced magnetic resonance imaging (MRI) is sparse.

OBJECTIVES

To analyze contrast-enhanced MRI findings of the clinically non-inflamed symptomatic pediatric wrist, focusing on the enhancing synovial and tenosynovial membrane. To evaluate the coexistent presence of (teno)synovial enhancement, joint fluid, bony depressions and medullary changes suggestive of bone marrow edema.

MATERIALS AND METHODS

We included 20 children (15 girls; age range: 7.5-17.6 years) who underwent contrast-enhanced MRI of the wrist, based on initial clinical indication, and eventually turned out to be unaffected by arthritic or orthopedic disorders. Various imaging characteristics of the synovium, tenosynovium, joint fluid, bone tissue and bone marrow were evaluated using existing MRI scoring systems.

RESULTS

In 3/20 (15%) children, mild or moderate-severe synovial enhancement was observed and 2/20 (10%) children showed mild tenosynovial enhancement/thickening. Joint fluid (11/20 children; 55%), bony depressions (20/20 children; 100%) and medullary changes suggestive of bone marrow edema (6/20; 30%) were found in a substantial percentage of children. The most frequently observed combination of coexisting imaging characteristics was bony depressions with ≥2 mm joint fluid, which was found in 7/20 (35%) children. Simultaneous presence of synovial and tenosynovial enhancement/thickening, bony depressions and medullary changes suggestive of bone marrow edema was observed in one child.

CONCLUSION

Several juvenile idiopathic arthritis-relevant MRI characteristics can be observed in the clinically non-inflamed symptomatic pediatric wrist.

Impaired bone microarchitecture in distal interphalangeal joints in patients with primary hypertrophic osteoarthropathy assessed by high-resolution peripheral quantitative computed tomography

This study aimed to investigate the bone impairment in finger joints in PHO patients by HR-pQCT. Results showed distinguished differences in bone architecture and biomechanics parameters at DIPs between PHO patients and healthy controls using HR-pQCT assessment. Besides, serum PGE2, hsCRP and ESR levels were found negatively correlated with total vBMD.

INTRODUCTION

This study aimed to investigate the bone impairment in finger joints in primary hypertrophic osteoarthropathy (PHO) patients firstly by high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

Fifteen PHO patients and 15 healthy controls were enrolled in this study. Bone erosions in hands at distal interphalangeal joints (DIPs) in both PHO patients and controls were evaluated by X-ray. Bone geometry, vBMD, microstructure parameters, and size of individual bone erosion were also measured at the 3rd DIP by HR-pQCT as well. Blood biochemistry levels between the two groups were also compared.

RESULTS

Compared to X-ray, HR-pQCT assessment were more sensitive for detection of bone erosions, with 14 PHO patients by HR-pQCT versus ten PHO patients by X-ray judged at the 3rd DIP. The average depth, width, and volume of erosions size in PHO patients were 1.38 ± 0.80 mm, 0.79 ± 0.27 mm, and 1.71 ± 0.52 mm³, respectively. The bone cross-areas including total area (+ 25.3%, p ≤ 0.05), trabecular area (+ 56.2%, p ≤ 0.05), and cortical perimeter (+ 10.7%, p ≤ 0.05) at the defined region of interest of 3rd DIP was significantly larger than controls. Total vBMD was 11.9% lower in PHO patients compared with the controls (p ≤ 0.05). Biochemical test results showed the increased levels of inflammatory cytokines, bone resorption markers, and joint degeneration markers in PHO patients. Serum prostaglandin PGE2, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) levels were found negatively correlated with total vBMD.

CONCLUSIONS

This study demonstrated higher sensitivity of the HR-pQCT measurement at DIPs by showing the differences in architecture and biomechanics parameters at DIPs between the PHO patients and healthy controls, which would be of interest clinically to investigate bone deterioration in PHO patients.

Pseudoerosions of Hands and Feet in Rheumatoid Arthritis: Anatomic Concepts and Redefinition

Rheumatoid arthritis is a chronic inflammatory disease characterized by the development of osseous and cartilaginous damage. The correct differentiation between a true erosion and other entities—then often called “pseudoerosions”—is essential to avoid misdiagnosing rheumatoid arthritis and to correctly interpret the progress of the disease. The aims of this systematic review were as follows: to create a definition and delineation of the term “pseudoerosion”, to point out morphological pitfalls in the interpretation of images, and to report on difficulties arising from choosing different imaging modalities. A systematic review on bone erosions in rheumatoid arthritis was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following search terms were applied in PubMed and Scopus: “rheumatoid arthritis”, “bone erosion”, “ultrasonography”, “radiography”, “computed tomography” and “magnetic resonance imaging”. Appropriate exclusion criteria were defined. The systematic review registration number is 138826. The search resulted ultimately in a final number of 25 papers. All indications for morphological pitfalls and difficulties utilizing imaging modalities were recorded and summarized. A pseudoerosion is more than just a negative definition of an erosion; it can be anatomic (e.g., a normal osseous concavity) or artefact-related (i.e., an artificial interruption of the calcified zones). It can be classified according to their configuration, shape, content, and can be described specifically with an anatomical term. “Calcified zone” is a term to describe the deep components of the subchondral, subligamentous and subtendinous bone, and may be applied for all non-cancellous borders of a bone, thus representing a third type of the bone matrix beside the cortical and the trabecular bone.

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.

Assessment of Cortical Interruptions in the Finger Joints of Patients With Rheumatoid Arthritis Using HR-pQCT, Radiography, and MRI

Small cortical interruptions may be the first sign of an erosion, and more interruptions can be found in patients with rheumatoid arthritis (RA) compared with healthy subjects. First, we compared the number and size of interruptions in patients with RA with healthy subjects using high-resolution peripheral quantitative CT (HR-pQCT). Second, we investigated the association between structural damage and inflammatory markers on conventional radiography (CR) and MRI with interruptions on HR-pQCT. Third, the added value of HR-pQCT over CR and MRI was investigated. The finger joints of 39 patients with RA and 38 healthy subjects were examined through CR, MRI, and HR-pQCT. CRs were scored using the Sharp/Van der Heijde method. MRI images were analyzed for the presence of erosions, bone marrow edema, and synovitis. HR-pQCT images were analyzed for the number, surface area, and volume of interruptions using a semiautomated algorithm. Descriptives were calculated and associations were tested using generalized estimating equations. Significantly more interruptions and both a larger surface area and the volume of interruptions were detected in the metacarpophalangeal joints of patients with RA compared with healthy subjects (median, 2.0, 1.42 mm² , and 0.48 mm³ versus 1.0, 0.69 mm² , and 0.23 mm³ , respectively; all p < 0.01). Findings on CR and MRI were significantly associated with more and larger interruptions on HR-pQCT (prevalence ratios [PRs] ranging from 1.03 to 7.74; all p < 0.01) in all subjects, and were consistent in patients with RA alone. Having RA was significantly associated with more and larger interruptions on HR-pQCT (PRs, 2.33 to 5.39; all p < 0.01), also after adjustment for findings on CR or MRI. More and larger cortical interruptions were found in the finger joints of patients with RA versus healthy subjects, also after adjustment for findings on CR or MRI, implying that HR-pQCT imaging may be of value in addition to CR and MRI for the evaluation of structural damage in patients with RA. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Measuring lupus arthritis activity using contrasted high-field MRI. Associations with clinical measures of disease activity and novel patterns of disease

Objective

Arthritis in SLE is poorly described, and there is no objective measure for quantification of arthritis. In this pilot study, we aim to assess the utility of the Rheumatoid Arthritis MRI Scoring System (RAMRIS) for the quantification of lupus arthritis.

Methods

Patients were eligible for entry into the study if they were evaluated at the Medical University of South Carolina Lupus Center and determined by their treating rheumatologist to have active hand arthritis due to SLE. Standard of care lupus activity measures were collected, along with a detailed physical exam. MRIs were obtained using standard musculoskeletal sequences with gadolinium contrast. Semiquantitative scoring of the images used the Outcome Measures in Rheumatology Clinical Trials RAMRIS system.

Results

RAMRIS demonstrates large amounts of synovitis, tenosynovitis, bone marrow oedema and erosive disease in only a minority of patients. Some patients were not scored as having any synovitis or tenosynovitis. We describe potential features of lupus arthritis that are not captured in the RAMRIS scores and may be contributing to symptoms.

Conclusion

Lupus arthritis is an entity separate from rheumatoid arthritis and requires the development of new quantitative methods to describe and quantitate it. MRI findings suggest the inadequacy of a typical lupus musculoskeletal measure including swollen/tender joint counts to assess the level of disease activity.

An automated algorithm for the detection of cortical interruptions and its underlying loss of trabecular bone; a reproducibility study

Background

We developed a semi-automated algorithm that detects cortical interruptions in finger joints using high-resolution peripheral quantitative computed tomography (HR-pQCT), and extended it with trabecular void volume measurement. In this study we tested the reproducibility of the algorithm using scan/re-scan data.

Methods

Second and third metacarpophalangeal joints of 21 subjects (mean age 49 (SD 11) years, 17 early rheumatoid arthritis and 4 undifferentiated arthritis, all diagnosed < 1 year ago) were imaged twice by HR-pQCT on the same day with repositioning between scans. The images were analyzed twice by one operator (OP1) and once by an additional operator (OP2), who independently corrected the bone contours when necessary. The number, surface and volume of interruptions per joint were obtained. Intra- and inter-operator reliability and intra-operator reproducibility were determined by intra-class correlation coefficients (ICC). Intra-operator reproducibility errors were determined as the least significant change (LSC_SD).

Results

Per joint, the mean number of interruptions was 3.1 (SD 3.6), mean interruption surface 4.2 (SD 7.2) mm², and mean interruption volume 3.5 (SD 10.6) mm³ for OP1. Intra- and inter-operator reliability was excellent for the cortical interruption parameters (ICC ≥0.91), except good for the inter-operator reliability of the interruption surface (ICC = 0.70). The LSC_SD per joint was 4.2 for the number of interruptions, 5.8 mm² for interruption surface, and 3.2 mm³ for interruption volume.

Conclusions

The algorithm was highly reproducible in the detection of cortical interruptions and their volume. Based on the LSC findings, the potential value of this algorithm for monitoring structural damage in the joints in early arthritis patients needs to be tested in clinical studies.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0255-7) contains supplementary material, which is available to authorized users.

Are MRI-detected erosions specific for RA? A large explorative cross-sectional study

OBJECTIVES

MRI is recommended in the diagnostic process of rheumatoid arthritis (RA) to detect joint damage early. MRI-detected erosions are also present in symptom-free controls, especially at older age. It is unclear if RA-specific MRI-detected erosions can be distinguished from 'physiological' erosions in symptom-free individuals. This study compared MRI-detected erosions of patients with RA with healthy controls and with other arthritides.

METHODS

589 newly presenting patients with early arthritis (238 RA, 351 other arthritides) and 193 symptom-free controls underwent contrast-enhanced 1.5T MRI of unilateral metacarpophalangeal and metatarsophalangeal (MTP) joints. Total erosion score (according to the Rheumatoid Arthritis MRI Scoring System), number, severity, location of erosions and simultaneous presence of MRI-detected inflammation (synovitis and/or bone marrow oedema) were compared; participants were categorised in three age groups (<40, 40-59, ≥60).

RESULTS

Patients with RA had statistically significant higher total erosion scores than controls but scores of individual persons largely overlapped. Grade ≥2 erosions and MTP5 erosions were specific for RA (specificity 98%-100% and 90%-98% for different age groups). MTP1 erosions were only specific if aged <40 (specificity 98%) and erosions with inflammation if aged <60 (specificity 91%-100%). ≥1 of the mentioned erosion characteristics were present in 29% of patients with RA. Comparing patients with RA with other arthritides revealed that grade ≥2 erosions and MTP5 erosions remained specific for RA (specificity ≥89%) as well as MTP1 erosions if aged <40 (specificity 93%), in contrast to erosions combined with inflammation (specificity 49%-85%).

CONCLUSIONS

Total erosion scores of individual persons were largely overlapping. Erosion characteristics specific for RA were identified, but were infrequently present. Caution is needed not to overestimate the value of MRI erosions in the diagnostic process.

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.

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.

The Reliability of a Semi-automated Algorithm for Detection of Cortical Interruptions in Finger Joints on High Resolution CT Compared to MicroCT

We developed a semi-automated algorithm for the detection of cortical interruptions in finger joints using high-resolution peripheral quantitative computed tomography (HR-pQCT). Here, we tested its reliability compared to microCT (µCT) as gold standard. Nineteen joints of 10 female anatomic index fingers were imaged by HR-pQCT and µCT (82 and 18 µm isotropic voxel sizes, respectively). The algorithm was applied for detection of cortical interruptions of different minimum diameters (range >0.16 to >0.50 mm). Reliability was tested at the joint level with intra-class correlation coefficient (ICC) for the number of interruptions and interruption surface, and at the level of a single interruption for matching between HR-pQCT and µCT with a fixed interruption diameter (>0.10 mm) on µCT. The positive predictive value (PPV_0.10mm) and sensitivity_0.10mm were evaluated. The mean number of interruptions per joint depended on the diameter cut-off and ranged from 3.4 to 53.5 on HR-pQCT and from 1.8 to 45.1 on µCT for interruptions >0.50 to >0.16 mm, respectively. Reliability at the joint level was almost perfect (ICC ≥0.81) for both the number and surface of interruptions >0.16 and >0.33 mm. As expected, the PPV_0.10mm increased with increasing interruption diameter from 84.9 to 100%, for interruptions >0.16 and >0.50 mm, respectively. However, the sensitivity_0.10mm decreased with increasing interruption diameter from 62.4 to 4.7%. This semi-automated algorithm for HR-pQCT in finger joints performed best for the detection of cortical interruptions with a minimum diameter of >0.16 or >0.33 mm, showing almost perfect reliability at the joint level and interruptions matched with those on µCT.

An automated algorithm for the detection of cortical interruptions on high resolution peripheral quantitative computed tomography images of finger joints

Objectives

To introduce a fully-automated algorithm for the detection of small cortical interruptions (≥0.246mm in diameter) on high resolution peripheral quantitative computed tomography (HR-pQCT) images, and to investigate the additional value of manual correction of the automatically obtained contours (semi-automated procedure).

Methods

Ten metacarpophalangeal joints from seven patients with rheumatoid arthritis (RA) and three healthy controls were imaged with HR-pQCT. The images were evaluated by an algorithm according to the fully- and semi-automated procedure for the number and surface of interruptions per joint. Reliability between the fully- and semi-automated procedure and between two independent operators was tested using intra-class correlation coefficient (ICC) and the proportion of matching interruptions. Validity of single interruptions detected was tested by comparing it to visual scoring, as gold standard. The positive predictive value (PPV) and sensitivity were calculated.

Results

The median number of interruptions per joint was 14 (range 2 to 59) and did not significantly differ between the fully- and semi-automated procedure (p = 0.37). The median interruption surface per joint was significantly higher with the fully- vs. semi-automated procedure (respectively, 8.6mm² vs. 5.8mm² and 6.1mm², p = 0.01). Reliability was almost perfect between the fully- and semi-automated procedure for both the number and surface of interruptions (ICC≥0.95) and the proportion of matching interruptions was high (≥76%). Also the inter-operator reliability was almost perfect (ICC≥0.97, proportion of matching interruptions 92%). The PPV ranged from 27.6% to 29.9%, and sensitivity from 69.7% to 76.3%. Most interruptions detected with the algorithm, did show an interruption on a 2D grayscale image. However, this interruption did not meet the criteria of an interruption with visual scoring.

Conclusion

The algorithm for HR-pQCT images detects cortical interruptions, and its interruption surface. Reliability and validity was comparable for the fully- and semi-automated procedures. However, we advise the use of the semi-automated procedure to assure quality. The algorithm is a promising tool for a sensitive and objective assessment of cortical interruptions in finger joints assessed by HR-pQCT.

Ultrasound detects subclinical joint inflammation in the hands and wrists of patients with systemic lupus erythematosus without musculoskeletal symptoms

Objectives

To assess the prevalence and severity of ultrasonographic abnormalities of the hand and wrist of asymptomatic patients with systemic lupus erythematosus (SLE) and compare these findings with those from patients with SLE with musculoskeletal signs or symptoms and healthy controls.

Methods

We conducted a prospective cross-sectional study that evaluated bilaterally, with grey-scale and power Doppler (PD) ultrasound (US), the dorsal hand (2nd to 5th metacarpophalangeal and 2nd to 5th proximal interphalangeal joints) and wrist (radiocarpal, ulnocarpal and intercarpal joints) of 30 asymptomatic patients with SLE, 6 symptomatic patients with SLE and 10 controls. Synovial hypertrophy (SH) and intra-articular PD signal were scored using semiquantitative grading scales (0–3). Individual scores were graded as normal (SH≤1 and PD=0) or abnormal (SH≥2 or PD≥1). Global indexes for SH and PD were also calculated. US findings were correlated with clinical and laboratory data and disease activity indexes.

Results

US detected SH (score ≥1) in 77% asymptomatic patients with SLE, mostly graded as minimal (score 1: 63%). 23% of the asymptomatic patients with SLE showed abnormal US PD findings (SH≥2 or PD≥1). SH was present in all symptomatic patients with SLE, mostly graded as moderate (grade 2: 67%), and with associated PD signal (83%). SH (score 1) was identified in 50% of controls, however, none presented abnormal US PD findings. SH index in the asymptomatic SLE group was higher than in the control group (2.0 (0–5) vs 0.5 (0–2), median (range), p=0.01) and lower than in the symptomatic SLE group (7.0 (4–23), median (range), p<0.001). No significant correlation was demonstrated between US PD findings and clinical or laboratory variables and disease activity indexes.

Conclusion

A small subgroup of asymptomatic patients with SLE may present subclinical joint inflammation. Global US scores and PD signal may be important in disease evaluation and therapeutic monitoring.

Heterogeneity of Cortical Breaks in Hand Joints of Patients with Rheumatoid Arthritis and Healthy Controls Imaged by High-resolution Peripheral Quantitative Computed Tomography

Objective.

Conventional radiographs (CR) of the hands are the gold standard for imaging bone erosions. The presence of bone erosions, reflected by the presence of cortical breaks, is a poor prognostic factor in patients with rheumatoid arthritis (RA). The availability of high-resolution peripheral quantitative computed tomography (HR-pQCT) enables detailed investigation of cortical breaks in rheumatic diseases. The aim of this image review is to show HR-pQCT images of the spectrum of cortical breaks with and without underlying trabecular bone changes in metacarpophalangeal (MCP) joints of healthy controls (HC) and patients with RA, with corresponding images on CR and magnetic resonance imaging (MRI).

Methods.

Second and third MCP joints of 41 patients (of which 10 were early RA with ≤ 2 years and 24 longstanding RA with ≥ 10 years of disease duration) and 38 HC were imaged by CR, MRI, and HR-pQCT (XtremeCT1, Scanco Medical AG). Representative images of the spectrum of cortical breaks were selected.

Results.

Cortical breaks were found in early and longstanding RA, but also in HC. They were heterogeneous in size, location, and number per joint, with a variety of surrounding cortical and underlying trabecular bone characteristics.

Conclusion.

Using HR-pQCT images of MCP joints, heterogeneous cortical breaks with and without surrounding trabecular bone changes were found, not only in RA but also in HC. The underlying mechanisms and significance of this spectrum of cortical breaks as found with high 3-D resolution needs further investigation.

Imaging of juvenile idiopathic arthritis. Part II: Ultrasonography and MRI

Juvenile idiopathic arthritis is the most common autoimmune systemic disease of the connective tissue affecting individuals in the developmental age. Radiography, which was described in the first part of this publication, is the standard modality in the assessment of this condition. Ultrasound and magnetic resonance imaging enable early detection of the disease which affects soft tissues, as well as bones. Ultrasound assessment involves: joint cavities, tendon sheaths and bursae for the presence of synovitis, intraand extraarticular fat tissue to visualize signs of inflammation, hyaline cartilage, cartilaginous epiphysis and subchondral bone to detect cysts and erosions, and ligaments, tendons and their entheses for signs of enthesopathies and tendinopathies. Magnetic resonance imaging is indicated in children with juvenile idiopathic arthritis for assessment of inflammation in peripheral joints, tendon sheaths and bursae, bone marrow involvement and identification of inflammatory lesions in whole-body MRI, particularly when the clinical picture is unclear. Also, MRI of the spine and spinal cord is used in order to diagnose synovial joint inflammation, bone marrow edema and spondylodiscitis as well as to assess their activity, location, and complications (spinal canal stenosis, subluxation, e.g. in the atlantoaxial region). This article discusses typical pathological changes seen on ultrasound and magnetic resonance imaging. The role of these two methods for disease monitoring, its identification in the pre-clinical stage and establishing its remission are also highlighted.

Magnetic Resonance Imaging-Detected Features of Inflammation and Erosions in Symptom-Free Persons From the General Population

OBJECTIVE

The use of magnetic resonance imaging (MRI)-detected inflammation and joint damage in the diagnosis of rheumatoid arthritis is recommended by a European League Against Rheumatism imaging task force. This recommendation is based on the sensitivity of MRI and not on specificity. Knowledge of the prevalence of MRI-detected features in symptom-free persons, however, is pivotal when considering MRI for diagnostic purposes.

METHODS

From November 2013 to December 2014, 196 symptom-free persons of different ages were recruited from the general population. Inclusion criteria were no history of inflammatory arthritis, no joint symptoms during the previous month, and no clinically detectable arthritis on physical examination. Contrast-enhanced MRIs of the dominant metacarpophalangeal (MCP), wrist, and metatarsophalangeal (MTP) joints were obtained using a 1.5T scanner and scored by 2 readers for synovitis, bone marrow edema, tenosynovitis, and erosions. For analyses at the joint level, MRI-detected inflammation was considered present if both readers scored the image as positive.

RESULTS

Of 193 persons scanned (ages 19-89 years), only 28% had no single inflammatory feature and 22% had no erosions. Primarily low-grade features were observed. All MRI features were positively correlated with age (P < 0.001). Preferential locations for synovitis were MCP2, MCP3, the wrists, and MTP1. Bone marrow edema was frequently present in MCP3, the scaphoid, and MTP1. Tenosynovitis was infrequent, except for in the extensor carpi ulnaris. Preferential locations for erosions were MCP2, MCP3, MCP5, the distal ulna, MTP1, and MTP5. Tables with age-, location-, and inflammation type-dependent frequencies were constructed. Simultaneous colocalized presence of synovitis, bone marrow edema, tenosynovitis, or erosions occurred.

CONCLUSION

MRI-detected inflammation and erosions are prevalent in symptom-free persons from the general population, especially at older ages and at preferential locations.

What is the prevalence of MRI-detected inflammation and erosions in small joints in the general population? A collation and analysis of published data

Introduction

MRI sensitively depicts erosions, bone marrow edema (BME) and synovitis in rheumatoid arthritis (RA). Recently developed European League Against Rheumatism (EULAR) recommendations stated that MRI is valuable to improve the certainty of a considered diagnosis and to detect structural damage at an early time point. However, these recommendations were mainly based on the data of patients with RA; prevalences of MRI features in the general population were not extensively explored. We reviewed the literature on MRI studies including symptom-free persons to assess the occurrence of MRI features.

Methods

Medical literature databases up to September 2013 were systematically reviewed for symptom-free persons with MRI data on metacarpophalangeal, wrist and metatarsophalangeal joints. Data were extracted and summarised. When allowed because of comparable scanning and scoring protocols, a mean frequency of features was calculated.

Results

Of the 338 articles screened, 31 studies evaluated MRI findings in symptom-free persons (n=516 in total). Both the imaging techniques (<1/≥1 T, with/without contrast enhancement) and the scoring methods (non-validated or RA MRI score (RAMRIS)) varied widely, prohibiting direct comparisons of the results of many studies. 15 studies scored data according to RAMRIS; combining data of similar joint regions showed that erosions (RAMRIS ≥1) were present in 33–52% of symptom-free persons. Similarly, synovitis was present in 27% and BME in 0–16% of symptom-free persons. The prevalence of MRI-detected erosions increased with age.

Conclusions

MRI features, erosions in particular, occur frequently in symptom-free persons. Before MRI can be implemented in the diagnostic process, larger studies should be conducted determining the degree and combination of MRI features that are disease specific.

MRI pattern of arthritis in systemic lupus erythematosus: a comparative study with rheumatoid arthritis and healthy subjects

OBJECTIVE

In this study we aimed to describe the magnetic resonance imaging (MRI) pattern of the distribution of bone marrow edema (BME) and joint erosion in hands and wrists of patients with systemic lupus erythematosus (SLE) with arthritis in comparison with rheumatoid arthritis (RA) and healthy subjects (H).

METHODS

SLE patients with arthritis (n = 50), patients with RA (n = 22), and H (n = 48) were enrolled. Every patient underwent a non-dominant hand (2nd-5th metacarpophalangeal joints) and wrist MRI without contrast injection with a low-field extremity dedicated 0.2-Tesla instrument.

RESULTS

BME was observed in two SLE patients in the hand (4%) and in 15 in the wrist (13%) versus three (30%), and 14 (63%) RA patients. No BME was found in H. Erosions were observed in the hand in 24 SLE patients (48%), 15 RA patients (68%), and 9 H (18 %); in the wrist, in 41 (82%) SLE, all RA and 47 (97%) H. The cumulative erosive burden in SLE was significantly higher than in H (c = 0.002) but similar to RA patients.

CONCLUSIONS

Joint involvement of the wrist in SLE is similar to RA and is not as rare as expected, as shown by the comparison with healthy subjects. On the contrary, the involvement of the hand in SLE is significantly lower compared to RA.

Detection of Subclinical Synovitis with Macrophage Targeting and Positron Emission Tomography in Patients with Rheumatoid Arthritis without Clinical Arthritis

Objective.

To determine whether macrophage targeting by (R)-11C-PK11195 positron emission tomography (PET) can visualize subclinical joint inflammation in patients with rheumatoid arthritis (RA) without clinical arthritis during or after treatment, with flare as clinical outcome measure.

Methods.

(R)-11C-PK11195 PET and contrast-enhanced magnetic resonance imaging (MRI) of hands/wrists were performed in 29 patients with RA without clinical arthritis. (R)-11C-PK11195 PET uptake (semiquantitative score 0–3) in metacarpophalangeal, proximal interphalangeal, and wrist joints (i.e., 22 joints per patient) was scored and summed to obtain a cumulative PET score (range 0–66). Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) was performed on similar joints. Synovitis and bone marrow edema scores (> 1) were summed to obtain a cumulative MRI score (range 0–288). Occurrence of flare was determined during 3-year followup.

Results.

Flare was observed in 17/29 patients (59%). (R)-11C-PK11195 PET showed enhanced tracer uptake in 16/29 patients (55%), of which 11 (69%) developed a flare. Highest cumulative PET scores (> 6, n = 3) corresponded with highest cumulative MRI scores (> 39) and were related to development of flare in hands/wrists within 6 months. Cumulative PET scores of patients developing a flare were higher than those of patients without a flare [median (interquartile range) 2 (0–4.5) vs 0 (0–1), p < 0.05]. In contrast, no significant differences were found between cumulative MRI scores of patients with and without a flare.

Conclusion.

(R)-11C-PK11195 PET showed enhanced uptake, pointing to presence of subclinical synovitis in over half of patients without clinical arthritis. (R)-11C-PK11195 PET may be of value for prediction of exacerbation of RA, since cumulative PET scores > 1 were associated with development of flare within 3 years.

Imaging of non-osteochondral tissues in osteoarthritis

OBJECTIVE

The aim of this review is to describe imaging techniques for evaluation of non-osteochondral structures such as the synovium, menisci in the knee, labrum in the hip, ligaments and muscles and to review the literature from recent clinical and epidemiological studies of OA.

METHODS

This is a non-systematic narrative review of published literature on imaging of non-osteochondral tissues in OA. PubMed and MEDLINE search for articles published up to 2014, using the keywords osteoarthritis, synovitis, meniscus, labrum, ligaments, plica, muscles, magnetic resonance imaging (MRI), ultrasound, computed tomography (CT), scintigraphy, and positron emission tomography (PET).

RESULTS

Published literature showed imaging of non-osteochondral tissues in OA relies primarily on MRI and ultrasound. The use of semiquantitative and quantitative imaging biomarkers of non-osteochondral tissues in clinical and epidemiological OA studies is reported. We highlight studies that have compared both imaging methodologies directly, and those that have established a relationship between imaging biomarkers and clinical outcomes. We provide recommendations as to which imaging protocols should be used to assess disease-specific changes regarding synovium, meniscus in the knee, labrum in the hip, and ligaments, and highlight potential pitfalls in their usage.

CONCLUSION

MRI and ultrasound are currently the most useful imaging modalities for evaluation of non-osteochondral tissues in OA. MRI evaluation of any tissue needs to be performed using appropriate MR pulse sequences. Ultrasound may be particularly useful for evaluation of small joints of the hand. Nuclear medicine and CT play a limited role in imaging of non-osteochondral tissues in OA.

Carpal pseudoerosions: a plain X-ray interpretation pitfall

OBJECTIVE

To examine in detail images of pseudoerosion of the wrist and hand on plain radiographs.

MATERIAL AND METHODS

The study was conducted with 28 cadaver wrists. During a single imaging session three techniques-plain radiography, tomosynthesis, and computed tomography-were used to visualize the wrist and hand specimens. For each technique, 20 radio-ulno-carpo-metacarpal sites known to present bone erosions in rheumatoid arthritis were analyzed by two radiologists using a standard system to score the cortical bone: normal, pseudoerosion, true erosion, or other pathology. Cohen's concordance analysis was performed to determine inter-observer and intra-observer (for the senior radiologist) agreement by site and by technique. Serial sections of two cadaver specimens were examined to determine the anatomical correlation of the pseudoerosions.

RESULTS

On the plain radiographs, the radiologists scored many images as pseudoerosion (7.3%), particularly in the distal ulnar portion of the capitate, the distal radial portion of the hamate, the proximal ulnar portion of the base of the third metacarpal, the proximal radial portion of the base of the fourth metacarpal, the distal ulnar portion of the hamate, and the proximal portion of the base of the fifth metacarpal. The computed tomography scan revealed that none of these doubtful images corresponded to true erosions. The anatomical correlation study showed that these images could probably be attributed to ligament insertions, thinner lamina, and enhanced cortical bone transparency.

CONCLUSION

Knowledge of the anatomical carpal localizations where pseudoerosions commonly occur is a necessary prerequisite for analysis of plain radiographs performed to diagnose or monitor rheumatoid arthritis.

The role of imaging in the evaluation of joint involvement in 102 consecutive patients with systemic lupus erythematosus

OBJECTIVE

To assess the prevalence of joint involvement in consecutive patients with systemic lupus erythematosus (SLE) by means of clinical assessment, joint US and MRI and to evaluate the sensitivity and specificity of physician evaluation of joint involvement.

METHODS

At enrollment, patients underwent a complete physical examination including a 44-joint count, and hand deformities were scored. On the day of enrollment, each patient underwent a non-dominant hand-wrist ultrasound (US) examination and a non-dominant hand-wrist MRI study without contrast injection.

RESULTS

One hundred and two patients (F 95, M 7) were enrolled. By physician examination hand or wrist involvement was diagnosed in 23.5%. At least one pathological finding was revealed by US examination at wrist and/or hand joints in 55%. We found a low sensitivity (46.5%) with high specificity (93.2%) of the physician assessment for the evaluation of joint involvement. The MRI imaging showed at least one erosion in 47.3% patients at the hand and in 98.9% at the wrist; in healthy subjects erosions were found in 19.6% and 97.8% at the hand and wrist, respectively.

CONCLUSIONS

In conclusion, (i) physicians tend to underestimate the severity of joint involvement in SLE; (ii) US assessment shows a high prevalence of joint and tendon involvement; and (iii) the MRI evaluation shows a high prevalence of damage, suggesting that joint involvement in SLE could be more severe than expected.

A double-blind, randomized controlled trial to compare the effect of biannual peripheral magnetic resonance imaging, radiography and standard of care disease progression monitoring on pharmacotherapeutic escalation in rheumatoid and undifferentiated inflammatory arthritis: study protocol for a randomized controlled trial

Background

Permanent joint damage is a major consequence of rheumatoid arthritis (RA), the most common and destructive form of inflammatory arthritis. In aggressive disease, joint damage can occur within 6 months from symptom onset. Early, intensive treatment with conventional and biologic disease-modifying anti-rheumatic drugs (DMARDs) can delay the onset and progression of joint damage. The primary objective of the study is to investigate the value of magnetic resonance imaging (MRI) or radiography (X-ray) over standard of care as tools to guide DMARD treatment decision-making by rheumatologists for the care of RA.

Methods

A double-blind, randomized controlled trial has been designed. Rheumatoid and undifferentiated inflammatory arthritis patients will undergo an MRI and X-ray assessment every 6 months. Baseline adaptive randomization will be used to allocate participants to MRI, X-ray, or sham-intervention groups on a background of standard of care. Prognostic markers, treating physician, and baseline DMARD therapy will be used as intervention allocation parameters. The outcome measures in rheumatology RA MRI score and the van der Heijde-modified Sharp score will be used to evaluate the MRI and X-ray images, respectively. Radiologists will score anonymized images for all patients regardless of intervention allocation. Disease progression will be determined based on the study-specific, inter-rater smallest detectable difference. Allocation-dependent, intervention-concealed reports of positive or negative disease progression will be reported to the treating rheumatologist. Negative reports will be delivered for the sham-intervention group. Study-based radiology clinical reports will be provided to the treating rheumatologists for extra-study X-ray requisitions to limit patient radiation exposure as part of diagnostic imaging standard of care. DMARD treatment dose escalation and therapy changes will be measured to evaluate the primary objective. A sample size of 186 (62 per group) patients will be required to determine a 36% difference in pharmacological treatment escalation between the three groups with intermediate dispersion of data with 90% power at a 5% level of significance.

Discussion

This study will determine if monitoring RA and undifferentiated inflammatory arthritis patients using MRI and X-ray every 6 months over 2 years provides incremental evidence over standard of care to influence pharmacotherapeutic decision-making and ultimately hinder disease progression.

Trial registration

This trial has been registered at ClinicalTrials.gov: NCT00808496 (registered on 12 December 2008).

A study of erosive phenotypes in lupus arthritis using magnetic resonance imaging and anti-citrullinated protein antibody, anti-RA33 and RF autoantibody status

OBJECTIVES

The aims of this study were to investigate the extent of MRI-determined joint disease (erosion and synovitis) in SLE and to link this to autoantibody profiles known to be relevant to SLE, including ACPA, RF and anti-RA33 antibodies.

METHODS

Contrast-enhanced MRI of the hand and wrist was performed in 34 symptomatic SLE patients and in 15 RA patients with similar disease duration. Images were scored by two observers using the OMERACT rheumatoid arthritis MRI scoring (RAMRIS) system. Findings were correlated with clinical examination and autoantibody status.

RESULTS

Erosions were present at the wrist in 93% of SLE patients and at the MCP joints in 61% of SLE patients. Despite the high prevalence of MRI-determined erosion, only 8.8% of SLE patients were ACPA positive, although these patients had a higher burden of erosive disease. There was no positive correlation with anti-RA33 titres and erosion scores in the SLE patients, but there was a negative correlation with anti-RA33 titres and total bone oedema scores in the SLE patients. Ninety-three per cent of SLE patients had at least grade 1 synovitis at one or more MCP joints, and wrist joint synovitis was present in all the SLE patients.

CONCLUSION

An MRI-determined joint erosive phenotype is common in SLE, even in ACPA-negative cases. The conventional radiographic observation that anti-RA33 is not positively associated with erosion in patients with RA was also found to be the case in SLE patients.

The specificity of ultrasound-detected bone erosions for rheumatoid arthritis

BACKGROUND

Bone erosion is one of the hallmarks of rheumatoid arthritis (RA), but also seen in other rheumatic diseases. The objective of this study was to determine the specificity of ultrasound (US)-detected bone erosions (including their size) in the classical 'target' joints for RA.

METHODS

Patients fulfilling the diagnostic criteria for RA, psoriatic arthritis, osteoarthritis or gout in addition to healthy volunteers were included. The following areas were examined by US: distal radius and ulna, 2nd, 3rd and 5th metacarpophalangeal (MCP), 2nd and 3rd proximal interphalangeal (PIP) and 1st and 5th metatarsophalangeal (MTP) joints. All joints were scanned in four quadrants using both semiquantitative (0-3) and quantitative (erosion diameter) scoring systems.

RESULTS

310 subjects were recruited. The inter-reader and intrareader agreements were good to excellent. US-detected bone erosions were more frequent but not specific for RA (specificity 32.9% and sensitivity 91.4%). The presence of erosions with semiquantitative score ≥2 in four target joints (2nd, 5rd MCP, 5th MTP joints and distal ulna) was highly specific for RA (specificity 97.9% and sensitivity 41.4%). Size of erosion was found to be associated with RA. Erosions of any size in the 5th MTP joint were both specific and sensitive for RA (specificity 85.4% and sensitivity 68.6%).

CONCLUSIONS

The presence of US-detected erosions is not specific for RA. However, larger erosions in selected joints, especially 2nd and 5rd MCP, 5th MTP joints and distal ulna, were highly specific for and predictive of RA.

Ultrasound assessment of elbow enthesitis in patients with seronegative arthropathies

BACKGROUND

Enthesopathy is an evolving area for applied clinical research. MRI is the gold standard in the diagnosis of elbow joint pathology, but recent reports indicate that ultrasound imaging is more sensitive and accurate than MRI in detecting enthesopathy of the heels and knees. Too many patients are under-diagnosed and/or misdiagnosed because the early pathological changes of enthesitis in the different types of seronegative arthropathies are not detected.

OBJECTIVES

This study was undertaken to describe the ultrasound features of elbow enthesitis in patients with seronegative arthropathies.

METHODS

We studied 38 diseased elbows in 38 patients with spondyloarthropathies (26 men and 12 women, mean age 32 years). All had elbow enthesopathy without typical conventional radiographic findings. Patients with histories of degenerative changes and/or local steroid injections were excluded. An HDI 3000 ATL ultrasound machine was used with a 5-12 MHz linear transducer to examine the affected elbow joints. The elbows of 10 normal healthy individuals were examined as normal controls. The patients were examined in the supine position with the elbow flexed 30°-50°. Longitudinal and transverse scans were obtained of the radiohumeral joint, the ulnahumeral joint, and the olecranon fossa. Two independent observers unaware of the clinical diagnosis read the ultrasound images and assessed the collateral ligaments, intratendinous echogenicity, tendon calcification, tendon thickness, presence of fluid, synovial proliferation, and bony changes. The reliability of the sonographic images was assessed by review of video recordings of the ultrasound examinations.

RESULTS

Ultrasound revealed loss of the fibrillar echopattern (100 %), lack of a homogenous pattern with loss of the tightly packed echogenic dots (100 %), peritendinous edema with flaring of the tendon margins (84.2 %), irregular fusiform tendon thickening (100 %), and hyperechoic intratendinous lesions with ill-defined focal defects (18.4 %). Ultrasound also detected intratendinous calcifications of both the common extensor and common flexor tendons (52.6 %). Bony erosions were seen at the tendon insertions into the lateral epicondyles (13.15 %).

CONCLUSION

Ultrasonographic features of elbow enthesitis differed from those described in knee and heel enthesitis. Ultrasound clearly showed early signs of tendon calcification, tendon edema, peritendinitis, and bony entheseal erosions. However, in elbow enthesitis the early bone erosion was associated with bone marrow edema, and the common extensor tendon was diffusely thickened. Ultrasound is a reliable, reproducible bedside imaging procedure. It improves the documentation of disease activity, progression, and treatment responses in patients with spondyloarthropathies. We recommend its use for the diagnosis and post-treatment follow-up of patients with enthesitis and seronegative spondyloarthropathies.