Update on Rheumatic Diseases in Clinical Practice: Recent Concepts and Developments

Diagnostic imaging is essential in the diagnostic process of rheumatic diseases. Given the heterogeneity of this group of diseases and the tremendous impact of novel therapeutic options, guidelines and recommendations regarding the optimal choice of the most appropriate technique/s are continuously revised and radiologists should always be up-to-date. Last, because of the continuous technological innovations, we will assist to the progressive application of advanced techniques and tools in rheumatology.

Magnetic Resonance Imaging (MRI)-Based Semi-Quantitative Methods for Rheumatoid Arthritis: From Scoring to Measurement

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the small joints of the hands and feet, characterized by pain, inflammation, and joint damage. In this context, magnetic resonance imaging (MRI) is useful to identify and monitor joint/tendon inflammation and the evolution of joint damage, playing a key role in treatment response evaluation, in addition to clinical measurements. Various methods to quantify joint inflammation and damage with MRI in RA have been developed, such as RA-MRI Score (RAMRIS), Early RA-MRI Score (ERAMRS), and Simplified RA-MRI Score (SAMIS). RAMRIS, introduced in 2002, offers an objective means to assess inflammation and damage via MRI in RA trials, encompassing findings such as synovitis, bone erosion, and edema/osteitis. Recently, an updated RAMRIS version was developed, which also includes the evaluation of joint space narrowing and tenosynovitis. The RAMRIS-5, which is a condensed RAMSIS version focusing on five hand joints only, has been proven to be a valuable resource for the semi-quantitative evaluation of RA joint damage, both in early and established disease. This narrative literature review will provide an overview of the MRI scoring systems that have been developed for the assessment of joint inflammation and structural damage in RA patients.

Autoimmune diseases of the spine and spinal cord

Magnetic resonance imaging (MRI) and clinicopathological tools have led to the identification of a wide spectrum of autoimmune entities that involve the spine. A clearer understanding of the unique imaging features of these disorders, along with their clinical presentations, will prove invaluable to clinicians and potentially limit the need for more invasive procedures such as tissue biopsies. Here, we review various autoimmune diseases affecting the spine and highlight salient imaging features that distinguish them radiologically from other disease entities.

A Stepwise Approach to Analyzing Musculoskeletal Imaging Data With Artificial Intelligence

The digitization of medical records and expanding electronic health records has created an era of "Big Data" with an abundance of available information ranging from clinical notes to imaging studies. In the field of rheumatology, medical imaging is used to guide both diagnosis and treatment of a wide variety of rheumatic conditions. Although there is an abundance of data to analyze, traditional methods of image analysis are human resource intensive. Fortunately, the growth of artificial intelligence (AI) may be a solution to handle large datasets. In particular, computer vision is a field within AI that analyzes images and extracts information. Computer vision has impressive capabilities and can be applied to rheumatologic conditions, necessitating a need to understand how computer vision works. In this article, we provide an overview of AI in rheumatology and conclude with a five step process to plan and conduct research in the field of computer vision. The five steps include (1) project definition, (2) data handling, (3) model development, (4) performance evaluation, and (5) deployment into clinical care.

Management of the Septic Wrist: A Systematic Review of Etiology and Therapeutic Strategies

Septic arthritis of the wrist can have severe deleterious effects on cartilage and bone if not promptly addressed. Expedient diagnosis and early medical intervention are important. The most effective strategy involves immediate arthrocentesis of the infected joint, enabling precise antibiotic selection based on joint fluid analysis. Diagnostic imaging is important in excluding fractures and identifying abscesses. This review explores the etiologic factors underlying septic wrist joint, identifying risk factors, and delineating optimal diagnosis and treatment approaches. The overarching goal is to impart valuable insights and guidance in the management of septic wrist joint, ensuring the highest quality patient care and optimal clinical outcomes.

Copper(II) Complexes with Carnosine Conjugates of Hyaluronic Acids at Different Dipeptide Loading Percentages Behave as Multiple SOD Mimics and Stimulate Nrf2 Translocation and Antioxidant Response in In Vitro Inflammatory Model

A series of copper(II) complexes with the formula [Cu2+Hy(x)Car%] varying the molecular weight (MW) of Hyaluronic acid (Hy, x = 200 or 700 kDa) conjugated with carnosine (Car) present at different loading were synthesized and characterized via different spectroscopic techniques. The metal complexes behaved as Cu, Zn-superoxide dismutase (SOD1) mimics and showed some of the most efficient reaction rate values produced using a synthetic and water-soluble copper(II)-based SOD mimic reported to date. The increase in the percentage of Car moieties parallels the enhancement of the I50 value determined via the indirect method of Fridovich. The presence of the non-functionalized Hy OH groups favors the scavenger activity of the copper(II) complexes with HyCar, recalling similar behavior previously found for the copper(II) complexes with Car conjugated using β-cyclodextrin or trehalose. In keeping with the new abilities of SOD1 to activate protective agents against oxidative stress in rheumatoid arthritis and osteoarthritis diseases, Cu2+ interaction with HyCar promotes the nuclear translocation of erythroid 2-related factor that regulates the expressions of target genes, including Heme-Oxigenase-1, thus stimulating an antioxidant response in osteoblasts subjected to an inflammatory/oxidative insult.

Imaging for patients presenting with a painful shoulder

Shoulder pain is a common cause of musculoskeletal presentation in primary care, where both traumatic and atraumatic pathologies can also lead to emergency department attendances. This article discusses common acute and chronic presentations of a painful shoulder, looking at the typical history of patients presenting with a painful shoulder, examination findings and the most appropriate imaging modalities to consider. Strengths and weaknesses of each imaging modality are discussed along with their role in aiding diagnosis, as well as management of the various pathologies encountered in primary and secondary care.

Assessment and Management of Atraumatic First Metatarsophalangeal Joint Pain

Nontraumatic pain in the first metatarsophalangeal joint is frequent and can be debilitating. The metatarsophalangeal joint complex comprises four articulating surfaces including the first metatarsal, the proximal phalanx, and tibial and fibular sesamoids, which are all contained within a synovial capsule. The most common causes of pain are hallux valgus and hallux rigidus. However, other diagnoses, such as functional hallux limitus, sesamoiditis, gout, and inflammatory autoimmune arthritis, need to be considered as well. A systematic approach is key to accurately diagnose the source of pain, which can sometimes be the result of more than one condition. The most important clinical information to obtain is a focused history, meticulous clinical examination based on understanding the precise anatomy and biomechanics of the first metatarsophalangeal joint, and analysis of the relevant imaging. Each pathology has a different treatment algorithm, as such, understanding the pathoanatomy and biomechanics is important in forming an effective treatment plan.

Intra-articular nanoparticles based therapies for osteoarthritis and rheumatoid arthritis management

Osteoarthritis (OA) and rheumatoid arthritis (RA) are chronic and progressive inflammatory joint diseases that affect a large population worldwide. Intra-articular administration of various therapeutics is applied to alleviate pain, prevent further progression, and promote cartilage regeneration and bone remodeling in both OA and RA. However, the effectiveness of intra-articular injection with traditional drugs is uncertain and controversial due to issues such as rapid drug clearance and the barrier afforded by the dense structure of cartilage. Nanoparticles can improve the efficacy of intra-articular injection by facilitating controlled drug release, prolonged retention time, and enhanced penetration into joint tissue. This review systematically summarizes nanoparticle-based therapies for OA and RA management. Firstly, we explore the interaction between nanoparticles and joints, including articular fluids and cells. This is followed by a comprehensive analysis of current nanoparticles designed for OA/RA, divided into two categories based on therapeutic mechanisms: direct therapeutic nanoparticles and nanoparticles-based drug delivery systems. We highlight nanoparticle design for tissue/cell targeting and controlled drug release before discussing challenges of nanoparticle-based therapies for efficient OA and RA treatment and their future clinical translation. We anticipate that rationally designed local injection of nanoparticles will be more effective, convenient, and safer than the current therapeutic approach.

Injectable Drug Delivery Systems for Osteoarthritis and Rheumatoid Arthritis

Joint diseases are one of the most common causes of morbidity and disability worldwide. The main diseases that affect joint cartilage are osteoarthritis and rheumatoid arthritis, which require chronic treatment focused on symptomatic relief. Conventional drugs administered through systemic or intra-articular routes have low accumulation and/or retention in articular cartilage, causing dose-limiting toxicities and reduced efficacy. Therefore, there is an urgent need to develop improved strategies for drug delivery, in particular, the use of micro- and nanotechnology-based methods. Encapsulation of therapeutic agents in delivery systems reduces drug efflux from the joint and protects against rapid cellular and enzymatic clearance following intra-articular injection. Consequently, the use of drug delivery systems decreases side effects and increases therapeutic efficacy due to enhanced drug retention in the intra-articular space. Additionally, the frequency of intra-articular administration is reduced, as delivery systems enable sustained drug release. This review summarizes various advanced drug delivery systems, such as nano- and microcarriers, developed for articular cartilage diseases.

Deep learning-based automatic-bone-destruction-evaluation system using contextual information from other joints

BACKGROUND

X-ray images are commonly used to assess the bone destruction of rheumatoid arthritis. The purpose of this study is to propose an automatic-bone-destruction-evaluation system fully utilizing deep neural networks (DNN). This system detects all target joints of the modified Sharp/van der Heijde score (SHS) from a hand X-ray image. It then classifies every target joint as intact (SHS = 0) or non-intact (SHS ≥ 1).

METHODS

We used 226 hand X-ray images of 40 rheumatoid arthritis patients. As for detection, we used a DNN model called DeepLabCut. As for classification, we built four classification models that classify the detected joint as intact or non-intact. The first model classifies each joint independently, whereas the second model does it while comparing the same contralateral joint. The third model compares the same joint group (e.g., the proximal interphalangeal joints) of one hand and the fourth model compares the same joint group of both hands. We evaluated DeepLabCut's detection performance and classification models' performances. The classification models' performances were compared to three orthopedic surgeons.

RESULTS

Detection rates for all the target joints were 98.0% and 97.3% for erosion and joint space narrowing (JSN). Among the four classification models, the model that compares the same contralateral joint showed the best F-measure (0.70, 0.81) and area under the curve of the precision-recall curve (PR-AUC) (0.73, 0.85) regarding erosion and JSN. As for erosion, the F-measure and PR-AUC of this model were better than the best of the orthopedic surgeons.

CONCLUSIONS

The proposed system was useful. All the target joints were detected with high accuracy. The classification model that compared the same contralateral joint showed better performance than the orthopedic surgeons regarding erosion.

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

Objective:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Update on imaging of the cervical spine in rheumatoid arthritis

Rheumatoid arthritis is a multisystem, autoimmune, inflammatory disorder with numerous musculoskeletal manifestations. Involvement of the cervical spine is common and may result in severe complications due to synovitis, erosions, pannus formation, spinal instability and ankylosis. The purpose of this article is to review the current role of imaging in the rheumatoid spine, with emphasis on radiographs and MRI.

Artificial Intelligence in Rheumatoid Arthritis: Current Status and Future Perspectives: A State-of-the-Art Review

Investigation of the potential applications of artificial intelligence (AI), including machine learning (ML) and deep learning (DL) techniques, is an exponentially growing field in medicine and healthcare. These methods can be critical in providing high-quality care to patients with chronic rheumatological diseases lacking an optimal treatment, like rheumatoid arthritis (RA), which is the second most prevalent autoimmune disease. Herein, following reviewing the basic concepts of AI, we summarize the advances in its applications in RA clinical practice and research. We provide directions for future investigations in this field after reviewing the current knowledge gaps and technical and ethical challenges in applying AI. Automated models have been largely used to improve RA diagnosis since the early 2000s, and they have used a wide variety of techniques, e.g., support vector machine, random forest, and artificial neural networks. AI algorithms can facilitate screening and identification of susceptible groups, diagnosis using omics, imaging, clinical, and sensor data, patient detection within electronic health record (EHR), i.e., phenotyping, treatment response assessment, monitoring disease course, determining prognosis, novel drug discovery, and enhancing basic science research. They can also aid in risk assessment for incidence of comorbidities, e.g., cardiovascular diseases, in patients with RA. However, the proposed models may vary significantly in their performance and reliability. Despite the promising results achieved by AI models in enhancing early diagnosis and management of patients with RA, they are not fully ready to be incorporated into clinical practice. Future investigations are required to ensure development of reliable and generalizable algorithms while they carefully look for any potential source of bias or misconduct. We showed that a growing body of evidence supports the potential role of AI in revolutionizing screening, diagnosis, and management of patients with RA. However, multiple obstacles hinder clinical applications of AI models. Incorporating the machine and/or deep learning algorithms into real-world settings would be a key step in the progress of AI in medicine.

A Systematic Approach to Diagnosing Arthritis Based on Radiological Imaging

:

Radiology plays key roles in diagnosis of arthritis. We herein suggest an algorithmic approach to diagnosing arthritis. First, the number of joint involvements is reviewed. Monoarticular arthritis includes septic arthritis, pigmented villonodular synovitis, and synovial chondromatosis. Second, polyarticular arthritis can be categorized by its characteristics: erosive, productive and mixed. Erosive disease includes rheumatoid arthritis, hemophilia, and amyloidosis while productive disease includes osteoarthritis, and hemochromatosis. Third, mixed diseases are subcategorized by symmetricity. Ankylosing spondylitis and inflammatory bowel disease related arthritis affect joints symmetrically while psoriatic arthritis, reactive arthritis, and crystalline arthropathy are asymmetric. Adjacent soft tissue density, periostitis, and bone density are ancillary findings that can be used as additional differential diagnostic clues. The final step in identifying the type of arthritis is to check whether the location is a site frequently affected by one particular disease over another. This systematic approach would be helpful for radiologist to diagnose arthritis.

Role of shear wave elastography of synovium to differentiate rheumatoid and tubercular arthritis

Background:

Synovitis is the underlying pathology in various arthritis, and sometimes, it is difficult to differentiate various arthritis clinically or even by imaging. The purpose of our study was to use shear wave elastography (SWE) to evaluate rheumatoid arthritis (RA) and tubercular (TB) arthritis and to differentiate them using synovial stiffness.

Methods:

The prospective study was performed on Supersonic Imagine Aixplorer Ultrasound (USG) machine using a linear array probe SL10-2 (2–10 MHz). A total of 29 participants, 15 of RA (ACR/EULAR criteria) and 14 of proven TB arthritis were included. Region of interest of 1 mm was applied on the hypertrophied synovium and quantitative SWE data in form of elasticity (kPa) and velocity (m/s) were measured. Discrete categorical data were presented as n (%). Mean values were recorded along with standard deviation and the range of values. To find a maximal cutoff value of elasticity and velocity - receiver operating characteristic curve were plotted.

Results:

The mean elasticity and velocity values were 54.81 ± 10.6 kPa and 4.2 m/s ± 0.42 for RA and 37 ± 10 kPa and 3.4 ± 0.47 m/s for TB group. Significant difference (P < 0.001) was seen in elastic modulus values between rheumatoid and TB group with cutoff of 43.6 kPa to differentiate the two groups (sensitivity – 86.7% and specificity – 80%). Similar significant (P < 0.001) results were seen with velocity values, with cutoff of 3.76 m/s (sensitivity – 86.7% and specificity – 80%).

Conclusion:

SWE shows the potential to be a useful adjunct to gray scale and color Doppler USG in differentiating various arthritis on the basis of elastic properties of the synovium. Elastic modulus and velocity are useful SWE quantitative parameters for synovial evaluation and can differentiate RA and TB arthritis.

Lower HDAC6 mRNA expression and promoter hypomethylation are associated with RA susceptibility

BACKGROUND/PURPOSE

Recent studies showed that Histone deacetylases 6 (HDAC6) inhibitors could improve arthritis in rheumatoid arthritis (RA) rodent models, whereas lower HDAC6 expression was observed in RA patients' synovial fibroblasts, raising the concerns to use HDAC6 inhibitors to treat RA patients. In the present study, we investigated the involvement of HDAC6 mRNA expression and promoter methylation in RA.

METHODS

The DNA and RNAs were extracted from the peripheral blood mononuclear cells (PBMCs) from 138 RA patients and 102 healthy controls. The pyrosequencing technique was used for promoter methylation analysis. The quantitative real-time polymerase chain reaction was used to determine the HDAC6 mRNA expression. The patients' clinical characteristics and disease biomarkers were recorded when blood sampling.

RESULTS

The HDAC6 mRNA expression was lower in the RA patients than controls (p = 0.001). The RA patients had significant hypomethylation of the HDAC6 promoter (p < 0.001). The HDAC6 promoter was hypo-methylated in the -229, -225, -144, and -142 CpG sites in RA patients (p < 0.05). Unexpectedly, promoter methylation and mRNA expression of the HDAC6 gene were positively associated (p < 0.001). The HDAC6 mRNA expression and promoter methylation status were associated with the risk of RA (p = 0.006 and 0.002, respectively). The inflammatory cytokines, TNF-α and IL-6, were significantly increased after HDAC6 knockdown in PMA-stimulated THP1 cells and SW982 cells (p < 0.05).

CONCLUSION

The HDAC6 mRNA expression and promoter methylation were lower in RA patients. Both HDAC6 mRNA expression level and promoter hypomethylation were associated the susceptibility of RA. HDAC6 inhibitors seem not proper for RA patients' treatment.

Knee alterations in rheumatoid arthritis: Comparison of US and MRI

Objective

This study was designed to compare the diagnostic efficacy of ultrasonography (US) and magnetic resonance imaging (MRI) in detecting changes in the knee of patients with rheumatoid arthritis (RA) and discover the possible association between the serological index and bone erosion detected by US.

Patients and methods

In this retrospective study, the US images and MRI findings of the knee in patients with RA from December 2017 to January 2020 were evaluated. Diagnostic outcomes were compared. The rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate, and anti-cyclic citrullinated peptide antibody (ACPA) levels of the patients were recorded. The relation between laboratory index and US findings was analyzed by multivariable logistic regression.

Results

US showed remarkable accuracy, sensitivity, and specificity in diagnosing synovitis, bone erosion, and soft tissue swelling. In terms of reliability, the agreement between US and MRI was moderate to almost perfect. Meanwhile, a positive association between ACPA level and bone erosion was observed in patients with RA.

Conclusions

US may have a role as the initial imaging modality in patients with RA. Patients with higher ACPA levels may need more active treatment because they are more likely to have bone erosion detected by US.

Surgical Management of the Lumbar Spine in Rheumatoid Arthritis

STUDY DESIGN

Narrative review.

OBJECTIVE

To provide an overview on the diagnosis and surgical management of rheumatoid involvement of the lumbar spine. Rheumatoid arthritis (RA) is a chronic inflammatory disease of synovial joints, most commonly appendicular followed by axial. Although cervical spine involvement of RA is well documented, data on lumbar spine involvement and surgical management remains limited.

METHODS

Using PubMed, studies published prior to November 2018 with the keywords "RA, etiology"; "RA, spine management"; "RA, surgical management"; "RA, treatment"; "RA, DMARDs"; "RA, lumbar spine"; "RA, spine surgical outcomes"; "RA, imaging" were evaluated.

RESULTS

The narrative review addresses the epidemiology, manifestations, imaging, surgical complications, and operative and nonoperative management of RA involvement of the lumbar spine.

CONCLUSIONS

Rheumatoid involvement of the lumbar spine can present with lower back pain, neurogenic claudication, radiculopathy, spinal deformity, and instability. Patients with RA have significantly higher rates of vertebral fractures and complications following surgical intervention. However, in the setting of instability and spinal deformity, thoughtful surgical planning in conjunction with optimal medical management is recommended.

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

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

Simple Erosion Narrowing Score of the hands as a predictor of cervical spine subluxation in rheumatoid arthritis

Background

Involvement of the cervical spine is common in patients with rheumatoid arthritis and can lead to devastating or even fatal consequences. Currently no guidelines exist as to whether radiographs of the cervical spine should be included in follow-up visits.

Objectives

To determine whether the Simple Erosion Narrowing Score (SENS) of the hands correlate with the presence of cervical spine subluxation in patients with rheumatoid arthritis.

Method

This was a retrospective, observational, cross-sectional study. A total of 56 rheumatoid arthritis patients with hand radiographs and lateral radiographs of the cervical spine were evaluated. The SENS of the hands and the presence of cervical spine subluxation were compared. The SENS of the hands was correlated with the prevalence of cervical spine subluxation, as was the erosion and joint space narrowing scores of the hands.

Results

A correlation between the SENS of the hands and the prevalence of cervical spine subluxation was confirmed. A higher prevalence of cervical spine subluxation correlated with an increase in the SENS of the hands (p = 0.0002). The erosion and joint space narrowing scores of the hands also correlated with the prevalence of cervical spine subluxation (p = 0.0001).

Conclusion

This study confirmed that a correlation exists between cervical spine subluxation, peripheral joint space erosions and joint space narrowing in patients with rheumatoid arthritis and SENS may therefore be used as a predictor of cervical spine disease.

Radiographically Occult Manifestation of Rheumatoid Arthritis in a Patient With Prolonged Clinical and Laboratory Evidence of Rampant Disease: A Case Report

OBJECTIVE

The purpose of this case report is to present a case of rampant rheumatoid synovitis and arthritis of a patient with a long duration of symptoms and no radiographic abnormalities of rheumatoid arthritis at the initial diagnosis.

CLINICAL FEATURES

A 49-year-old Hispanic woman presented to a chiropractic teaching clinic with an 8-month history of bilateral, symmetrical hand pain and stiffness noted specifically in her second and third metacarpophalangeal joints. The patient has reported no other health changes and no history of rheumatoid arthritis in the family.

INTERVENTION AND OUTCOME

Based on this patient's complaint, initial bilateral 3-view radiographic examination of the hands using computed radiography was performed. Despite prolonged history of inflammatory joint pain and rheumatoid arthritis confirmed by abnormally high levels of rheumatoid factor, C-reactive protein, and anti-cyclic citrulline peptide antibodies, the patient had no radiographic evidence of rheumatoid arthritis during the initial and repeat radiographic studies.

CONCLUSION

Some patients with rheumatoid arthritis may present with rampant clinical and laboratory abnormalities despite an apparent lack of radiographically detectable rheumatoid arthritis. This case demonstrates that astute clinicians should primarily rely on the results of clinical and laboratory abnormalities of rheumatoid arthritis and not be deterred or mislead by an apparent lack of radiographic changes at diagnosis. If the diagnosis of rheumatoid arthritis requires diagnostic imaging confirmation, then magnetic resonance imaging or diagnostic ultrasound of the hands should be used, especially if the initial radiographic assessment remains unrewarding.

High-resolution MRI of flexor tendon pulleys using a 16-channel hand coil: disease detection and differentiation of psoriatic and rheumatoid arthritis

Background

To evaluate the value of 3 Tesla (T) magnetic resonance imaging (MRI) changes of flexor tendon pulleys for the differentiation of psoriatic (PsA) and rheumatoid arthritis (RA), using a novel 16-channel high-resolution hand coil.

Methods

Seventeen patients with active PsA, 20 patients with active RA, and 16 healthy controls (HC) underwent high-resolution 3 T MRI using the dedicated 16-channel hand coil. Images were analyzed by three independent readers for the degree of inflammatory changes, thickness of flexor tendon pulleys, and comparison to the outcome measures for RA clinical trials (OMERACT) PsA MRI score (PsAMRIS) and to its sub-scores. For correlation analyses, Spearman rho correlation was calculated.

Results

Flexor tendon pulleys were thicker in PsA than in RA patients (mean difference 0.16 mm, p < 0.001) and HC (mean difference 0.2 mm, p < 0.001) and showed a higher degree of associated inflammatory changes (mean difference from RA 4.7, p = 0.048; mean difference from HC 14.65, p < 0.001). Additionally, there was a strong correlation of accessory pulley inflammation and PsAMRIS and its acute-inflammatory sub-scores, flexor tenosynovitis, synovitis, and periarticular inflammation (for the second digit synovitis ρ = 0.72, flexor tenosynovitis ρ = 0.7, overall PsAMRIS ρ = 0.72, p < 0.01). Similar robust correlations were evident in digits 3–5. Weaker correlations were evident in RA (synovitis ρ = 0.49, flexor tenosynovitis ρ = 0.49, periarticular inflammation ρ = 0.4).

Conclusion

The assessment of MRI changes of flexor tendon pulleys is potentially beneficial for disease detection in PsA, as well as for its distinction from RA and HC.

Trial registration

2014123117, December 2014.

Mimickers of Hill-Sachs Lesions [Formula: see text]

The purpose of this article is to describe the imaging appearance, etiology, clinical features, and treatment of rare presentations of common bone and joint diseases known to mimic Hill-Sachs lesions. Knowledge of uncommonly encountered manifestations of ankylosing spondylitis, rheumatoid arthritis, septic joint, hyperparathyroidism, hydroxyapatite deposition disease, malignant bone tumors, and benign bone cysts which mimic traumatic Hill-Sachs lesions is important for radiologists to guide the clinical care of patients who present with shoulder symptoms.

Unusual Cerebral Involvement of Rheumatoid Arthritis Mimicking a Tumor

BACKGROUND

The central nervous system's involvement in Rheumatoid Arthritis (RA) is infrequent and can be life-threatening. Mass-like CNS involvement is an unusual presentation. A 45 year old man had suffered seropositive rheumatoid arthritis for five years referred to our hospital with one-week history of right-sided facial paralysis, left hemiparesis and headache.

DISCUSSION

MRI demonstrated hyperintense mass-like lesion extended from mesencephalon to right hippocampus and basal ganglia on T2 and FLAIR images. On DWI, restricted diffusion was not present. After contrast administration, minimal contrast enhancement was noted. After methotrexate and steroid treatment, the size had been markedly shrunken on the follow-up images. The clinical symptoms were also improved.

CONCLUSION

To our knowledge, the mass-like presentation was not reported in the literature. We report an unusual case of brain involvement of rheumatoid arthritis mimicked tumor.

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).

The synergy between radiographic and macroscopic observation of skeletal lesions on dry bone

The diagnosis of bone lesions is a fundamental part of the study of skeletal remains, both in the archeological and forensic context. On the one side, the literature proved the relevance of radiography for the detection of bone lesions; on the other side, the careful macroscopic observation of the morphology of bone lesions is often underestimated. For this study, we examined and performed plain radiography on 14 skeletons of the CAL Milano Cemetery Skeletal Collection diagnosed with rheumatoid arthritis, diabetes, multiple myeloma, metastatic cancer, and osteomalacia to compare the macroscopic morphology and radiographic visualization of bone lesions. At least 200 osteolytic lesions and 65 areas of proliferative bone reaction (either spongiosclerotic or periosteal) were studied. We realized "comparative sets" of macroscopic pictures and radiographic imaging of the same skeletal elements to allow comparisons of detection and recognition of bone lesions. As a result, while trabecular lesions may be lost through naked eye observation, many lesions can also be unperceived on radiographs due to contrast, including periosteal reactions, osteolytic lesions, and spongiosclerosis. The aim of this research was to investigate the strengths and pitfalls of digital radiography and macroscopic analysis and to demonstrate the synergy of a complementary approach between the two methods for lesion analysis in dry bone.

Erosive rheumatoid arthritis in a young patient with mirror hand

Mirror hand is a congenital anomaly characterised by duplication of the ulnar ray, resulting in polydactyly and functional disability of the hand. It can cause arthralgias and weakness in intrinsic muscles of the hand. We present a young woman who had a surgically corrected mirror hand and subsequently developed aggressive rheumatoid arthritis, which increased her limitations to a significant degree. Early diagnosis and treatment in such cases is very important to prevent long-term disability.

[Upcoming value of gene expression analysis in rheumatology]

Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology, which involves disturbance in immune system signaling pathway functions, damage of other tissues, pain and joint destruction. Modern treatment attempts to improve pathophysiological and biochemical mechanisms damaged by the disease. However, due to the RA patient heterogeneity personalized approach to treatment is required; the choice of personalized treatment is complicated by the variability of patient's response to treatment. Gene expression analysis might serve a tool for the disease control and therapy personification for inhibition of inflammation and pain as well as for prevention of joint destruction.

The Diagnostic Implications of Two Cases of Known Rheumatoid Arthritis from the CAL Milano Cemetery Skeletal Collection

Rheumatoid arthritis (RA) is the most common erosive arthropathy and is of particular interest to forensic sciences. However, its diagnosis on bones remains challenging. We examined two skeletons from the CAL Milano Cemetery Skeletal Collection diagnosed with the pathology during life, to test the validity of the diagnostic criteria on bones. The first showed typical lesions of RA described in the literature. The second exhibited secondary osteoarthrosis, suggesting long-standing RA. A differential diagnosis including all four seronegative spondyloarthropathies, erosive osteoarthritis, gout and neuropathic arthropathy was also considered. Both shared common features consistent with the literature: symmetric erosions of bones in the hands, wrists and elbows, sparing of the distal interphalangeal joints, and the absence of sacroiliac and spinal fusion. Given the paucity of studies on known RA skeletons, these results strengthen the criteria for diagnosis. This research is, to our knowledge, the first study on identified and known individuals with RA.

The role of hybrid bone SPECT/CT imaging in the work-up of the limping patient: a symptom-based and joint-oriented review

A vast spectrum of lower limb bone and joint disorders (hip, knee, ankle, foot) present with a common clinical presentation: limping. Too often this symptom generates an inefficient cascade of imaging studies. This review attempts to optimise the diagnostic effectiveness of bone scintigraphy using the hybrid SPECT/CT technique in relation to the diagnostic clues provided by other imaging modalities, discusses the appropriate clinical indications, optimal scintigraphic procedures and illustrates updated image pattern-oriented reporting. Frequent lower limb bone and joint pathologies that can now be reliably diagnosed using hybrid bone SPECT/CT imaging will be reviewed. Bone SPECT/CT can be an effective problem-solving tool in patients with persistent limping when careful history taking, clinical examination, and first-line imaging modalities fail to identify the underlying cause.

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.

Comparison of the clinical effectiveness of US grading scoring system vs MRI in the diagnosis of early rheumatoid arthritis (RA)

BACKGROUND

As an irreversible disease, a treatment delay can negatively affect treatment response in rheumatoid arthritis (RA). Ultrasound and MRI have played an important role in assessing disease progression and response to treatment in RA for many years. The present study was designed to compare the diagnostic efficacy of ultrasound grading and MRI in early RA.

METHODS

In this retrospective study, 62 early RA patients within 12 months of symptom onset were included. DAS28, rheumatoid factor (RF), CRP, ESR, and anti-cyclic citrullinated peptide antibody (CCP) of the patients were measured. Bilateral hand joints and wrists were examined by ultrasonography (US) and MRI; diagnosis outcome was compared. Relationship between DAS28 scores, laboratory parameters, and ultrasound findings were analyzed.

RESULTS

Ultrasound and MRI had an equivalent diagnosis value in synovitis, joint effusion, and tenosynovitis. The detection rate of synovitis, arthroedema, and tenosynovitis on ultrasound and MRI was very close (P > 0.05). The detection rate of bone erosion was lower in ultrasonography than that in MRI (P < 0.05). There were significant differences between power Doppler ultrasonography (PDUS) and gray-scale ultrasonography (GSUS) in the diagnosis of synovitis (χ 2 = 3.92, P < 0.05); the sensitivity of GSUS was better than that of PDUS (P < 0.05). PDUS was positively correlated with DAS28, ESR, CRP, and CCP (P < 0.01), but not correlated with RF and disease duration (P > 0.05). GSUS was positively correlated with RF and CRP (P < 0.01), but not correlated with DAS28, CCP, ESR, and disease duration (P > 0.05). Bone erosion was positively correlated with disease duration, CCP, and RF (P < 0.01) and was not correlated with DAS28, ESR, and CRP (P > 0.05).

CONCLUSION

Ultrasonography has a high reliability in the diagnosis of early RA in synovitis, joint effusion, tenosynovitis, and bone erosion. Ultrasonography and clinical and laboratory parameters had a great correlativity. Both ultrasound and MRI are effective techniques. In view of the advantages of low cost and convenience, ultrasound may be a better choice during early RA diagnosis.

The clinical utility of gene expression examination in rheumatology

Rheumatoid arthritis (RA) is a chronic inflammatory disease with unknown etiology that affects various pathways within the immune system, involves many other tissues and is associated with pain and joint destruction. Current treatments fail to address pathophysiological and biochemical mechanisms involved in joint degeneration and the induction of pain. Moreover, RA patients are extremely heterogeneous and require specific treatments, the choice of which is complicated by the fact that not all patients equally respond to therapy. Gene expression analysis offer tools for patient management and personalization of patient’s care to meet individual needs in controlling inflammation and pain and delaying joint destruction.

Imaging Findings of Metabolic Bone Disease

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of (a) bone mass, (b) structure mineral homeostasis, (c) bone turnover, or (d) growth. Osteoporosis, the most common metabolic bone disease, results in generalized loss of bone mass and deterioration in the bone microarchitecture. Impaired chondrocyte development and failure to mineralize growth plate cartilage in rickets lead to widened growth plates and frayed metaphyses at sites of greatest growth. Osteomalacia is the result of impaired mineralization of newly formed osteoid, which leads to characteristic Looser zones. Hypophosphatasia is a congenital condition of impaired bone mineralization with wide phenotypic variability. Findings of hyperparathyroidism are the result of bone resorption, most often manifesting as subperiosteal resorption in the hand. Renal osteodystrophy is the collection of skeletal findings observed in patients with chronic renal failure and associated secondary hyperparathyroidism and can include osteopenia, osteosclerosis, and "rugger jersey spine." Hypoparathyroidism is most commonly due to iatrogenic injury, and radiographic findings of hypoparathyroidism reflect an overall increase in bone mass. Thyroid hormone regulates endochondral bone formation; and congenital hypothyroidism, when untreated, leads to delayed bone age and absent, irregular, or fragmented distal femoral and proximal tibial epiphyses. Soft-tissue proliferation of thyroid acropachy is most often observed in the hands and feet. The findings of acromegaly are due to excess growth hormone secretion and therefore proliferation of the bones and soft tissues. Vitamin C deficiency, or scurvy, impairs posttranslational collagen modification, leading to subperiosteal hemorrhage and fractures. ^©RSNA, 2016.

Cervical spine instability in the course of rheumatoid arthritis - imaging methods

Cervical spine is affected in more than a half of patients with rheumatoid arthritis (RA). Depending on the degree of damage to the individual joints and ligaments RA-related cervical spine instability takes the form of atlanto-axial subluxation, subaxial subluxation or cranial settling. In the advanced cases spinal stenosis can occur as well as spinal cord injuries with typical neurological symptoms. The identification of patients with cervical spine instability before the occurrence of neurological complications still constitutes a diagnostic challenge.

The article presents the methods of cervical spine imaging with the use of plain radiographs, magnetic resonance imaging (MRI) and computed tomography (CT). We discuss the advantages and disadvantages associated with each method and the possibility of its application in the diagnosis of cervical spine instability in RA. The knowledge of the above mentioned issues is indispensable to select an appropriate time for surgical intervention.

Conventional Radiology in Rheumatoid Arthritis

In clinical practice, the conventional radiography is still the radiologic method for the diagnosis of rheumatoid arthritis (RA). Moreover, it provides a quick overview of the symptomatic joints to narrow the differential diagnosis and to evaluate progression. RA is a polyarticular disease with bilateral and symmetric involvement of the peripheral joints, especially small joints, and less frequently, the cervical spine. The radiologic features are soft tissue swelling, periarticular osteoporosis, erosions, loss of joint space, and in advanced disease, osteolysis and typical subluxations or deformities, such as ulnar deviation.

Laser acupuncture versus reflexology therapy in elderly with rheumatoid arthritis

The purposes of this study are to determine and compare efficacy of laser acupuncture versus reflexology in elderly with rheumatoid arthritis. Thirty elderly patients with rheumatoid arthritis aged between 60 and 70 years were classified into two groups, 15 patients each. Group A received laser acupuncture therapy (904 nm, beam area of 1cm², power 100 mW, power density 100 mW/cm², energy dosage 4 J, energy density 4 J/cm², irradiation time 40 s, and frequency 100,000 Hz). The acupuncture points that were exposed to laser radiation are LR3, ST25, ST36, SI3, SI4, LI4, LI11, SP6, SP9, GB25, GB34, and HT7. While group B received reflexology therapy, both offered 12 sessions over 4 weeks. The changes in RAQoL, HAQ, IL-6, MDA, ATP, and ROM at wrist and ankle joints were measured at the beginning and end of treatment. There was significant decrease in RAQoL, HAQ, IL-6, and MDA pre/posttreatment for both groups (p < 0.05); significant increase in ATP pre/posttreatment for both groups (p < 0.05); significant increase in ankle dorsi-flexion, plantar-flexion, wrist flexion, extension, and ulnar deviation ROM pre/posttreatment in group A (p < 0.05); and significant increase in ankle dorsi-flexion and ankle plantar-flexion ROM pre/posttreatment in group B (p < 0.05). Comparison between both groups showed a statistical significant decrease in MDA and a statistical significant increase in ATP in group A than group B. Percent of changes in MDA was 41.82%↓ in group A versus 21.68%↓ in group B; changes in ATP was 226.97%↑ in group A versus 67.02%↑ in group B. Moreover, there was a statistical significant increase in ankle dorsi-flexion, ankle plantar-flexion, wrist flexion, wrist extension, and radial deviation in group A than group B. Laser therapy is associated with significant improvement in MDA and ATP greater than reflexology. In addition, it is associated with significant improvement in ankle dorsi-flexion, ankle plantar-flexion, wrist flexion, wrist extension, and radial deviation greater than reflexology in elderly patients with rheumatoid arthritis.

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.

High-Resolution US of Rheumatologic Diseases

For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

Visual detection of cortical breaks in hand joints: reliability and validity of high-resolution peripheral quantitative CT compared to microCT

Background

To study the reliability and validity of high-resolution peripheral quantitative CT (HR-pQCT) with microCT (μCT) as gold standard in the visual detection of cortical breaks in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints.

Methods

Ten cadaveric fingers (10 MCP and 9 PIP joints) were imaged by HR-pQCT and μCT and visually analyzed by two independent readers. Intra- and interreader reliability were evaluated for the presence (yes/no, kappa statistics) and the total number (intraclass correlation coefficient, ICC) of cortical breaks. Sensitivity, specificity, positive and negative predictive value (PPV respectively NPV) of HR-pQCT in detecting cortical breaks were calculated.

Results

With HR-pQCT, mean 149 cortical breaks were identified and with μCT mean 129 (p < 0.05). Intrareader reliability for the presence of a cortical break per quadrant was 0.52 (95 % CI 0.48–0.56) and 0.71 (95 % CI 0.67–0.75) for HR-pQCT and μCT, respectively, and for the total number of cortical breaks 0.61 (95 % CI 0.49–0.70) and 0.75 (95 % CI 0.68–0.82). Interreader reliability for the presence of a cortical break per quadrant was 0.37 (95 % CI 0.33–0.41) and 0.45 (95 % CI 0.41–0.49) for HR-pQCT and μCT, respectively, and for the number of cortical breaks 0.55 (95 % CI 0.43–0.65) and 0.54 (95 % CI 0.35–0.67). Sensitivity, specificity, PPV and NPV of HR-pQCT were 81.6, 64.0, 81.6, and 64 % respectively.

Conclusion

Cortical breaks were commonly visualized in MCP and PIP joints with HR-pQCT and μCT. Reliability of both HR-pQCT and μCT was fair to moderate. HR-pQCT was highly sensitive to detect cortical breaks with μCT as gold standard.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1148-y) contains supplementary material, which is available to authorized users.

The establishment of a porcine rheumatoid arthritis model: Collagen induced arthritis minipig model

Rheumatoid arthritis (RA) research has been largely dependent on collagen induced arthritis (CIA) rodent models, however, they may not translate well to humans due to innate differences in the size, physiology and lifespan. The present study aimed to establish a CIA porcine model with the physical, hematological, histopathological and etiological properties closer to their human equivalent in an attempt to better meet the needs of RA research. Three month old minipigs were administered of bovine type II collagen (CII) emulsified with complete Freund's adjuvants on Day 1 and incomplete Freund's adjuvants on Day 22, via an intradermal or intra-articular route. The clinical, radiological and hematological assessments of immunized animals were made periodically until Day 43, during which period the onset and progression of arthritis was recorded and characterized. In addition, the histopathological and micro-tomographic assessments of the cartilage degradation with regard to mononuclear cell infiltration, and joint deformity indicated a higher severity in the intradermal injection group over the intra-articular group. With confirmation of the susceptibility to heterogeneous CII for arthritis induction in minipig, the potential suitability of this test system as a large animal model for RA has been demonstrated.

Rheumatic diseases of the spine: imaging diagnosis

Spinal involvement is common both in the spondyloarthritides and in rheumatoid arthritis, in which the cervical segment is selectively affected. Rheumatoid involvement of the cervical spine has characteristic radiologic manifestations, fundamentally different patterns of atlantoaxial instability. Magnetic resonance imaging (MRI) is the technique of choice for evaluating the possible repercussions of atlantoaxial instability on the spinal cord and/or nerve roots in patients with rheumatoid arthritis as well as for evaluating parameters indicative of active inflammation, such as bone edema and synovitis. Axial involvement is characteristic in the spondyloarthritides and has distinctive manifestations on plain-film X-rays, which reflect destructive and reparative phenomena. The use of MRI has changed the conception of spondyloarthritis because it is able to directly detect the inflammatory changes that form part of the disease, making it possible to establish the diagnosis early in the disease process, when plain-film X-ray findings are normal (non-radiographic axial spondyloarthritis), to assess the prognosis of the disease, and to contribute to treatment planning.