Abatacept inhibits inflammation and onset of rheumatoid arthritis in individuals at high risk (ARIAA): a randomised, international, multicentre, double-blind, placebo-controlled trial.

BACKGROUND: Individuals with anti-citrullinated protein antibodies (ACPAs) and subclinical inflammatory changes in joints are at high risk of developing rheumatoid arthritis. Treatment strategies to intercept this pre-stage clinical disease remain to be developed. We aimed to assess whether 6-month treatment with abatacept improves inflammation in preclinical rheumatoid arthritis. METHODS: The abatacept reversing subclinical inflammation as measured by MRI in ACPA positive arthralgia (ARIAA) study is a randomised, international, multicentre, double-blind, placebo-controlled trial done in 14 hospitals and community centres across Europe (11 in Germany, two in Spain, and one in the Czech Republic). Adults (aged ≥18 years) with ACPA positivity, joint pain (but no swelling), and signs of osteitis, synovitis, or tenosynovitis in hand MRI were randomly assigned (1:1) to weekly subcutaneous abatacept 125 mg or placebo for 6 months followed by a double-blind, drug-free, observation phase for 12 months. The primary outcome was the proportion of participants with any reduction in inflammatory MRI lesions at 6 months. The primary efficacy analysis was done in the modified intention-to-treat population, which included participants who were randomly assigned and received study medication. Safety analyses were conducted in participants who received the study medication and had at least one post-baseline observation. The study was registered with the EUDRA-CT (2014-000555-93). FINDINGS: Between Nov 6, 2014, and June 15, 2021, 139 participants were screened. Of 100 participants, 50 were randomly assigned to abatacept 125 mg and 50 to placebo. Two participants (one from each group) were excluded due to administration failure or refusing treatment; thus, 98 were included in the modified intention-to-treat population. 70 (71%) of 98 participants were female and 28 (29%) of 98 were male. At 6 months, 28 (57%) of 49 participants in the abatacept group and 15 (31%) of 49 participants in the placebo group showed improvement in MRI subclinical inflammation (absolute difference 26·5%, 95% CI 5·9-45·6; p=0·014). Four (8%) of 49 participants in the abatacept group and 17 (35%) of 49 participants in the placebo group developed rheumatoid arthritis (hazard ratio [HR] 0·14 [0·04-0·47]; p=0·0016). Improvement of MRI inflammation (25 [51%] of 49 participants in the abatacept group, 12 [24%] of 49 in the placebo group; p=0·012) and progression to rheumatoid arthritis (17 [35%] of 49, 28 [57%] of 49; HR 0·14 [0·04-0·47]; p=0·018) remained significantly different between the two groups after 18 months, 12 months after the end of the intervention. There were 12 serious adverse events in 11 participants (four [8%] of 48 in the abatacept group and 7 [14%] of 49 in the placebo group). No deaths occurred during the study. INTERPRETATION: 6-month treatment with abatacept decreases MRI inflammation, clinical symptoms, and risk of rheumatoid arthritis development in participants at high risk. The effects of the intervention persist through a 1-year drug-free observation phase. FUNDING: Innovative Medicine Initiative.

Goodbye to the term 'ankylosing spondylitis', hello 'axial spondyloarthritis': time to embrace the ASAS-defined nomenclature.

Ankylosing spondylitis (AS) is the historic term used for decades for the HLA-B27-associated inflammatory disease affecting mainly the sacroiliac joints (SIJ) and spine. Classification criteria for AS have radiographic sacroiliitis as a dominant characteristic. However, with the availability of MRI of SIJ, it could be demonstrated that the disease starts long before definite SIJ changes become visible on radiographs. The Assessment of SpondyloArthritis international Society, representing a worldwide group of experts reached consensus on changes in the nomenclature pertaining to axial spondyloarthritis (axSpA), such as the terminology of diagnosis and of assessment of disease activity tools. These are important changes in the field, as experts in axSpA are now in agreement that the term axSpA is the overall term for the disease. A further differentiation, of which radiographic versus non-radiographic is only one aspect, may be relevant for research purposes. Another important decision was that the terms AS and radiographic axSpA (r-axSpA) can be used interchangeably, but that the preferred term is r-axSpA. Based on the decision that axSpA is the correct terminology, a proposal was made to officially change the meaning of the ASDAS acronym to 'Axial Spondyloarthritis Disease Activity Score'. In addition, for simplification it was proposed that the term ASDAS (instead of ASDAS-CRP) should be preferred and applied to the ASDAS calculated with C reactive protein (CRP). It is hoped that these changes will be used consequently for education, in textbooks, manuscripts and presentations.

Cortical matrix remodeling as a hallmark of relapsing-remitting neuroinflammation in MR elastography and quantitative MRI.

Multiple sclerosis (MS) is a chronic neuroinflammatory disease that involves both white and gray matter. Although gray matter damage is a major contributor to disability in MS patients, conventional clinical magnetic resonance imaging (MRI) fails to accurately detect gray matter pathology and establish a clear correlation with clinical symptoms. Using magnetic resonance elastography (MRE), we previously reported global brain softening in MS and experimental autoimmune encephalomyelitis (EAE). However, it needs to be established if changes of the spatiotemporal patterns of brain tissue mechanics constitute a marker of neuroinflammation. Here, we use advanced multifrequency MRE with tomoelastography postprocessing to investigate longitudinal and regional inflammation-induced tissue changes in EAE and in a small group of MS patients. Surprisingly, we found reversible softening in synchrony with the EAE disease course predominantly in the cortex of the mouse brain. This cortical softening was associated neither with a shift of tissue water compartments as quantified by T2-mapping and diffusion-weighted MRI, nor with leukocyte infiltration as seen by histopathology. Instead, cortical softening correlated with transient structural remodeling of perineuronal nets (PNNs), which involved abnormal chondroitin sulfate expression and microgliosis. These mechanisms also appear to be critical in humans with MS, where tomoelastography for the first time demonstrated marked cortical softening. Taken together, our study shows that neuroinflammation (i) critically affects the integrity of PNNs in cortical brain tissue, in a reversible process that correlates with disease disability in EAE, (ii) reduces the mechanical integrity of brain tissue rather than leading to water accumulation, and (iii) shows similar spatial patterns in humans and mice. These results raise the prospect of leveraging MRE and quantitative MRI for MS staging and monitoring treatment in affected patients.

A Good Response to Nonsteroidal Antiinflammatory Drugs Does Not Discriminate Patients With Longstanding Axial Spondyloarthritis From Controls With Chronic Back Pain.

OBJECTIVE: To compare the response to nonsteroidal antiinflammatory drugs (NSAIDs) in patients with longstanding axial spondyloarthritis (axSpA) and controls with back pain (nonspondyloarthritis [non-SpA]). METHODS: Consecutive outpatients with chronic back pain (axSpA or non-SpA), were prospectively recruited. Any previous NSAIDs were withdrawn 2 days before study start (baseline). Back pain was assessed using a numerical rating scale (NRS; range 0-10) starting at 2 hours after baseline and several times thereafter up to 4 weeks. "Any response" to NSAIDs was defined as improvement of back pain on the NRS > 2 units, and "good response" as improvement > 50%, compared to baseline. RESULTS: Among 233 patients included, 68 had axSpA (29.2%) and 165 had non-SpA back pain (70.8%). The mean age was 42.7 (SD 10.7) vs 49.3 (SD 11.1) years, symptom duration 15.1 (SD 11.1) years vs 14.6 (SD 11.9) years, and pain score 5.9 (SD 2.3) vs 6.3 (SD 2.0), respectively. Overall, of patients with axSpA or non-SpA back pain, 30.9% vs 29.1% of patients showed any response and 23.5% vs 16.4% of patients showed a good response after 4 weeks, respectively (P value not significant). No differences were found in the rapidity of response or between subgroups of patients based on demographics, including different stages of axSpA. CONCLUSION: No major differences in the response to NSAIDs were found between patients with axSpA and those with non-SpA with longstanding chronic back pain. The item in the Assessment of SpondyloArthritis international Society classification criteria on "response to NSAIDs" needs more study.

[The role of HLA-B27 in the pathogenesis and diagnosis of axial spondyloarthritis : 50 years after discovery of the strong genetic association]. / Zur Rolle von HLA-B27 in der Pathogenese und Diagnostik der axialen Spondyloarthritis : 50 Jahre nach Entdeckung der starken genetischen Assoziation.

BACKGROUND: The association of the human lymphocyte antigen B27 (HLA-B27) with ankylosing spondylitis (AS), also now called axial spondylarthritis (axSpA), was first described 50 years ago. OBJECTIVE: This article gives an overview of the available knowledge on the topic. MATERIAL AND METHODS: This is a narrative review based on the experience of the authors. RESULTS: The HLA-B27 is a member of the HLA class I family of genes of the major histocompatibility complex (MHC). The prevalence of HLA-B27 in the central European population is approximately 8 %, i.e., the vast majority of carriers of HLA-B27+ remain healthy. The frequency of HLA-B27 shows a decline from north to south. The HLA-B27 explains only 30 % of the genetic burden of axSpA. The prevalence of the disease correlates with the frequency of HLA-B27 in the population, i.e., there are geographic differences. Approximately 60-90 % of patients with axSpA worldwide are HLA-B27+. Some 200 subtypes of HLA-B27 can be differentiated using the polymerase chain reaction (PCR). In Thailand and Sardinia two subtypes were found that are not associated with axSpA. The physiological function of HLA class I molecules is the defence of the organism against microbes. Microbial peptides are presented to the immune system, which can be specifically attacked by CD8+ T­cells. Genetic polymorphisms of the enzyme endoplasmic reticulum aminopeptidase 1 (ERAP1), which breaks down peptides in the endoplasmic reticulum, are associated only with HLA-B27+ diseases. DISCUSSION: The pathogenesis of axSpA is unclear but a major hypothesis is that of the arthritogenic peptides. In this it is assumed that potentially pathogenic foreign or autologous peptides can be presented by HLA-B27. If nothing else, HLA-B27 plays an important role in the diagnosis, classification and determination of the severity of axSpA.

[First classification criteria for diseases caused by calcium pyrophosphate deposition (CPPD)-Translation, explanation and assessment]. / Erste Klassifikationskriterien für durch Kalziumpyrophosphatablagerungen verursachte Erkrankungen ­ Übersetzung, Erläuterung und Bewertung.

AIM: For diseases caused by calcium pyrophosphate deposition (CPPD), validated classification criteria were previously lacking. In this article the recently developed and validated classification criteria are translated, explained, and assessed. METHODS: In recent years a multinational research group developed classification criteria for CPPD disease with the support by the European Alliance of Associations for Rheumatology (EULAR) and the American College of Rheumatology (ACR), following an established method. The developed criteria were finally validated in an independent cohort. The translation and annotation of the new first classification criteria were carried out in an iterative procedure in consensus with the authors. RESULTS: The presence of a crowned dens syndrome or calcium pyrophosphate crystals in the synovial fluid in patients with pain, swelling or sensitivity of the joints (entry criterion) is sufficient for the classification as CPPD disease, where the symptoms cannot be completely explained by another rheumatic disease (exclusion criterion). If these symptoms are not present, a count of more than 56 points based on weighted criteria comprised of clinical features and the results of laboratory and imaging investigations can be included for classification as a CPPD disease. These criteria had a sensitivity of 92.2% and a specificity of 87.9% in the derivation cohorts (190 CPPD cases and 148 mimics), whereas the sensitivity was 99.2% and the specificity 92.5% in the validation cohorts (251 CPPD cases and 162 mimics). CONCLUSION: The ACR/EULAR classification criteria 2023 of a CPPD disease will facilitate clinical research in this field. The use in the clinical routine will show how practical the criteria are.

Looking back on 51 years of the Carol Nachman Prize in Rheumatology-significance for the field of spondyloarthritis research.

The city and casino of Wiesbaden, capital of the German state Hessen, have endowed the Carol Nachman Prize to promote research work in the field of rheumatology since 1972. The prize, endowed with 37,500 €, is the second highest medical award in Germany and serves to promote clinical, therapeutic, and experimental research work in the field of rheumatology. In June 2022, the 50-year anniversary was celebrated. In the symposium preceding the award ceremony, an overview was given on the significance of spondyloarthritis for the work of the awardees in the past 30 years. This overview has now been put together to inform the interested community of the work performed, including the opinion of the awardees regarding what they consider to be their most important contribution.

The effect of anti-inflammatory treatment on depressive symptoms in spondyloarthritis: does the type of drug matter?

OBJECTIVE: To investigate the effect of pharmacological treatment of SpA on depressive symptoms and explore whether this effect differs between drug classes. METHODS: Data from the observational Assessment of SpondyloArthritis international Society Health Index Validation Study were used. Patients were assessed at baseline and after initiation of NSAIDs/conventional synthetic DMARDs (csDMARDs)/TNF inhibitors (TNFis). Depressive symptoms were assessed with the Hospital Anxiety and Depression Scale depression subscale [HADS-D; 0-21 (best-worst)]. Covariables included demographics and disease characteristics, including disease activity [Ankylosing Spondylitis Disease Activity Score (ASDAS)/BASDAI]. The change in HADS-D from baseline was compared between treatments (NSAIDs/csDMARDs/TNFis) with analysis of variance and multivariable regression analysis. RESULTS: A total of 304 patients were included; 102/45/157 initiated NSAIDs/csDMARDs/TNFis and 260 (85%) / 44 (15%) had axial/peripheral SpA. At baseline, the mean HADS-D was 6.9 (s.d. 4.2); 126 (42%) were possibly depressed (HADS-D ≥8) and 66 (22%) were probably depressed (HADS-D ≥11). At follow-up, depressive symptoms significantly improved in all treatment groups. In multivariable regression without disease activity measures, initiating TNFis compared with NSAIDs was associated with greater improvement in depressive symptoms [ß = -1.27 (95% CI -2.23, -0.32)] and lower odds of possible depression at follow-up [odds ratio 0.47 (95% CI 0.23, 0.94)]. This association was attenuated after additional adjustment for disease activity (ASDAS/BASDAI) but not CRP. csDMARDs did not differ from NSAIDs regarding their effect on HADS-D. Between-drug class results were confirmed in axial SpA (axSpA), although less clear in peripheral SpA. CONCLUSION: Treatment of active SpA also improves depressive symptoms. Especially in axSpA, TNFis have a greater effect than NSAIDs, which is mainly explained by a stronger effect on disease activity. We found no evidence for a direct link between CRP-mediated inflammation and depressive symptoms in SpA.

Characterization of renal fibrosis in rats with chronic kidney disease by in vivo tomoelastography.

Chronic kidney disease (CKD) is characterized by structural changes, such as tubular atrophy, renal fibrosis, and glomerulosclerosis, all of which affect the viscoelastic properties of biological tissues. However, detection of renal viscoelasticity changes because diagnostic markers by in vivo elastography lack histopathological validation through animal models. Therefore, we investigated in vivo multiparametric magnetic resonance imaging (mp-MRI), including multifrequency magnetic resonance elastography-based tomoelastography, in the kidneys of 10 rats with adenine-induced CKD and eight healthy controls. Kidney volume (in mm3 ), water diffusivity (apparent diffusion coefficient [ADC] in mm2 /s), shear wave speed (SWS; in m/s; related to stiffness), and wave penetration rate (PR; in m/s; related to inverse viscosity) were quantified by mp-MRI and correlated with histopathologically determined renal fibrosis (collagen area fraction [CAF]; in %). Kidney volume (40% ± 29%, p = 0.009), SWS (11% ± 12%, p = 0.016), and PR (20% ± 15%, p = 0.004) were significantly increased in CKD, which was accompanied by ADC (-24% ± 27%, p = 0.02). SWS, PR, and ADC were correlated with CAF with R = 0.63, 0.75, and -0.5 (all p < 0.05), respectively. In the CKD rats, histopathology showed tubule dilation due to adenine crystal deposition. Collectively, our results suggest that collagen accumulation during CKD progression transforms soft-compliant renal tissue into a more rigid-solid state with reduced water mobility. We hypothesized that tubule dilation-a specific feature of our model-might lead to higher intraluminal pressure, which could also contribute to elevated renal stiffness. Tomoelastography is a promising tool for noninvasively assessing disease progression, detecting biomechanical properties that are sensitive to different pathologic features of CKD.

How tissue fluidity influences brain tumor progression.

Mechanical properties of biological tissues and, above all, their solid or fluid behavior influence the spread of malignant tumors. While it is known that solid tumors tend to have higher mechanical rigidity, allowing them to aggressively invade and spread in solid surrounding healthy tissue, it is unknown how softer tumors can grow within a more rigid environment such as the brain. Here, we use in vivo magnetic resonance elastography (MRE) to elucidate the role of anomalous fluidity for the invasive growth of soft brain tumors, showing that aggressive glioblastomas (GBMs) have higher water content while behaving like solids. Conversely, our data show that benign meningiomas (MENs), which contain less water than brain tissue, are characterized by fluid-like behavior. The fact that the 2 tumor entities do not differ in their soft properties suggests that fluidity plays an important role for a tumor's aggressiveness and infiltrative potential. Using tissue-mimicking phantoms, we show that the anomalous fluidity of neurotumors physically enables GBMs to penetrate surrounding tissue, a phenomenon similar to Saffman-Taylor viscous-fingering instabilities, which occur at moving interfaces between fluids of different viscosity. Thus, targeting tissue fluidity of malignant tumors might open horizons for the diagnosis and treatment of cancer.

[Swelling of the salivary glands and sicca symptoms in Kimura's disease, a rare rheumatological differential diagnosis with an indicatively high IgE serum level-A current overview after literature search]. / Speicheldrüsenschwellung und Sicca-Symptomatik bei Morbus Kimura, einer seltenen rheumatologischen Differenzialdiagnose mit wegweisend hohem IgE-Serumspiegel ­ eine aktuelle Übersicht nach Literatursuche.

Rheumatic and musculoskeletal diseases (RMD) include various diseases with sometimes rather different symptoms, some of which are locally confined and others show systemic features. Autoimmune phenomena, such as those occurring in Sjögren's syndrome, often cause symptoms such as xerostomia and xerophthalmia in association with inflammation of the salivary glands. The pathogenesis of these diseases is only partly clarified. This is similar to allergic diseases, which are otherwise clearly different with respect to the symptoms and pathomechanisms but swelling of the salivary glands can also rarely occur here. As this is a possible differential diagnosis of Sjögren's syndrome or also IgG4-associated diseases, and such a case was recently described, a literature search was carried out in PubMed, the results of which are presented here and summarized in this article in a brief overview.

Magnetic resonance imaging in polymyalgia rheumatica-contrast enhancement is not always needed.

BACKGROUND: Extracapsular inflammation at entheseal sites in the pelvic girdle as demonstrated by magnetic resonance imaging (MRI) was shown to be useful as an additional tool for diagnosing polymyalgia rheumatica (PMR). However, it is unclear whether MRI needs to be performed with contrast enhancement or whether oedema-sensitive sequences are sufficient. OBJECTIVE: To evaluate the performance of T2w TIRM (turbo inversion recovery magnitude) imaging compared to fat-saturated contrast-enhanced (ce) T1w at predefined pelvic sites to detect extracapsular inflammation in patients with PMR. METHODS: A total of 120 pelvic MRIs of patients with pelvic girdle pain, 40 with clinically diagnosed PMR and 80 controls, were retrospectively scored by three blinded radiologists separately evaluating the MRI with and without contrast enhancement at 19 previously defined pelvic structures. The intra- and interrater reliability and the diagnostic performance of both techniques were statistically analysed and evaluated. RESULTS: The detection of inflammatory MRI signals correlated moderately between both techniques (Cohen's κ 0.583). With ceT1w imaging 20.7% more sites were detected as inflamed compared to T2w TIRM in PMR patients. Inter- and intrareader reliability was superior with ceT1w imaging. If the inflammatory signal was detected at three sites bilaterally including the origin of the rectus femoris muscle or adductor longus muscle, the sensitivity and specificity was 100% and 97.1% by ceT1w imaging vs. 80.8% and 93.3% by T2w TIRM, respectively. CONCLUSION: Contrast enhancement is superior to oedema-sensitive MRI in the detection of extracapsular inflammation in PMR. However, using T2w TIRM also detects many but not all PMR cases.

[Translation of the 2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis and linguistic validation in German-speaking countries with healthcare professionals]. / Übersetzung der 2018 EULAR Empfehlungen zu körperlicher Aktivität von Menschen mit entzündlich-rheumatischen und degenerativen Erkrankungen ins Deutsche und sprachliche Validierung im deutschsprachigen Raum mit medizinischen Fachpersonen.

BACKGROUND: Regular physical activity is beneficial for people with rheumatic diseases and one of the cornerstones in its management. Based on the international recommendations of the World Health Organization for the general population, the "2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis" provide evidence-based recommendations on the prescription, performance, and implementation of physical activity exercises in this population for the first time. AIM: Translation of the 2018 EULAR recommendations into German and linguistic validation in Germany, Austria and Switzerland. METHODS: A professional translation of the EULAR recommendations into the German language was performed and revised by German-speaking experts from all three countries. The translation was validated by healthcare professionals consisting of rheumatologists, occupational therapists, physiotherapists, nurses, and medical assistants in a field test. In each of the three countries, eight structured interviews were conducted on comprehensibility, wording, completeness, and feasibility. The experts then discussed changes until consensus was reached and indicated the level of agreement with the final translation. RESULTS: The translation of the EULAR recommendations was substantially revised. Based on the results of the cognitive test, formulations were adapted in order to increase comprehensibility. The level of agreement between 10 (SD 0.0) and 8.9 (SD 1.5) was very high. DISCUSSION: The final German version of the EULAR recommendations is comprehensible and accepted across all three German-speaking countries. It can help to improve the structure and clarity of the handling of physical activity and promote physical activity for healthcare providers and patients.

[Rheumatology training positions in Germany]. / Rheumatologische Weiterbildungsstellen in Deutschland.

BACKGROUND: In the next few years many general practitioners and specialists will retire. As in other disciplines the question arises in rheumatology whether sufficient training positions are available to maintain or expand the supply of care according to demand. Therefore, the German Society of Rheumatology (DGRh) has assigned its committee for education and training to review the currently available training opportunities in Germany. The aim of this work is the quantitative survey of the training capacity to become a specialist in internal medicine and rheumatology. METHODS: Within the framework of this study, a survey was conducted via the homepages of the 17 state medical associations to determine the postgraduate medical officers, their place of work and the duration of their postgraduate training capabilities. Based on the data, a nationwide survey of training positions was conducted. RESULTS: Specialized rheumatology training is established at 229 training centers in Germany, whereby data from 187 training sites were available for analysis. The training locations are distributed as followed: 52.4% clinical sector and 47.6% outpatient sector. In total, 478.4 training positions are available in Germany (clinical sector: 391.4 and outpatient sector: 87) and 17.2% of the positions (clinical sector: 11.4% and outpatient sector: 43.1%) are not occupied. CONCLUSION: Based on this study, it can be shown that most of the continuing education positions are available in the clinical sector. In contrast, half of the training positions in the outpatient area are not filled. In order to improve the training situation, it is essential to integrate outpatient colleagues into the training program. This presupposes that further training is supported or financed by the healthcare system. In this context, optimal rheumatological care must be permanently guaranteed throughout Germany in order to provide sufficient care for the approximately 2 million patients with inflammatory rheumatic diseases.

Comparison of inversion methods in MR elastography: An open-access pipeline for processing multifrequency shear-wave data and demonstration in a phantom, human kidneys, and brain.

PURPOSE: Magnetic resonance elastography (MRE) maps the viscoelastic properties of soft tissues for diagnostic purposes. However, different MRE inversion methods yield different results, which hinder comparison of values, standardization, and establishment of quantitative MRE markers. Here, we introduce an expandable, open-access, webserver-based platform that offers multiple inversion techniques for multifrequency, 3D MRE data. METHODS: The platform comprises a data repository and standard MRE inversion methods including local frequency estimation (LFE), direct-inversion based multifrequency dual elasto-visco (MDEV) inversion, and wavenumber-based (k-) MDEV. The use of the platform is demonstrated in phantom data and in vivo multifrequency MRE data of the kidneys and brains of healthy volunteers. RESULTS: Detailed maps of stiffness were generated by all inversion methods showing similar detail of anatomy. Specifically, the inner renal cortex had higher shear wave speed (SWS) than renal medulla and outer cortex without lateral differences. k-MDEV yielded higher SWS values than MDEV or LFE (full kidney/brain k-MDEV: 2.71 ± 0.19/1.45 ± 0.14 m/s, MDEV: 2.14 ± 0.16/0.99 ± 0.11 m/s, LFE: 2.12 ± 0.15/0.89 ± 0.06 m/s). CONCLUSION: The freely accessible platform supports the comparison of MRE results obtained with different inversion methods, filter thresholds, or excitation frequencies, promoting reproducibility in MRE across community-developed methods.

Microscopic multifrequency MR elastography for mapping viscoelasticity in zebrafish.

PURPOSE: The zebrafish (Danio rerio) has become an important animal model in a wide range of biomedical research disciplines. Growing awareness of the role of biomechanical properties in tumor progression and neuronal development has led to an increasing interest in the noninvasive mapping of the viscoelastic properties of zebrafish by elastography methods applicable to bulky and nontranslucent tissues. METHODS: Microscopic multifrequency MR elastography is introduced for mapping shear wave speed (SWS) and loss angle (φ) as markers of stiffness and viscosity of muscle, brain, and neuroblastoma tumors in postmortem zebrafish with 60 µm in-plane resolution. Experiments were performed in a 7 Tesla MR scanner at 1, 1.2, and 1.4 kHz driving frequencies. RESULTS: Detailed zebrafish viscoelasticity maps revealed that the midbrain region (SWS = 3.1 ± 0.7 m/s, φ = 1.2 ± 0.3 radian [rad]) was stiffer and less viscous than telencephalon (SWS = 2.6 ± 0. 5 m/s, φ = 1.4 ± 0.2 rad) and optic tectum (SWS = 2.6 ± 0.5 m/s, φ = 1.3 ± 0.4 rad), whereas the cerebellum (SWS = 2.9 ± 0.6 m/s, φ = 0.9 ± 0.4 rad) was stiffer but less viscous than both (all p < .05). Overall, brain tissue (SWS = 2.9 ± 0.4 m/s, φ = 1.2 ± 0.2 rad) had similar stiffness but lower viscosity values than muscle tissue (SWS = 2.9 ± 0.5 m/s, φ = 1.4 ± 0.2 rad), whereas neuroblastoma (SWS = 2.4 ± 0.3 m/s, φ = 0.7 ± 0.1 rad, all p < .05) was the softest and least viscous tissue. CONCLUSION: Microscopic multifrequency MR elastography-generated maps of zebrafish show many details of viscoelasticity and resolve tissue regions, of great interest in neuromechanical and oncological research and for which our study provides first reference values.

Certolizumab pegol treatment in axial spondyloarthritis mitigates fat lesion development: 4-year post-hoc MRI results from a phase 3 study.

OBJECTIVES: Fat lesions (FLs) on MRI T1 sequences are considered to be early indicators of structural spinal progression in axial spondyloarthritis (axSpA) patients. In this post-hoc analysis from RAPID-axSpA, we assess whether tumour necrosis factor inhibitor (TNFi) treatment over 4 years impacts FLs in spinal vertebral edges (VEs) of patients with axSpA. METHODS: In RAPID-axSpA (NCT01087762), a 4-year, phase 3 randomized trial, participants were randomized to certolizumab pegol (CZP; 400 mg loading dose at Weeks 0/2/4 then 200/400 mg every 2/4 weeks) or placebo (PBO) at baseline; PBO-randomized participants switched to CZP at Week 16/24 (denoted PBO-randomized/CZP). Spinal MRI scans were taken at Weeks 0, 12, 48, 96 and 204. Changes in proportions of VEs with FLs are reported as odds ratios (ORs) between time points. RESULTS: Overall, 136 participants (CZP: 89, PBO-randomized/CZP: 47) had a baseline and ≥1 post-baseline MRI. The OR (95% confidence interval) vs baseline of FLs was higher in PBO-randomized/CZP vs CZP-randomized participants at Weeks 48 [3.35 (2.16-5.19) vs 1.45 (1.07-1.97)], 96 [2.62 (1.77-3.88) vs 1.84 (1.36-2.48)] and 204 [2.55 (1.59-4.06) vs 1.71 (1.23-2.37)]. Across 204 weeks, FLs increased more in VEs with baseline inflammation [Week 204 OR: 4.84 (2.56-9.18)] than those without [OR: 1.15 (0.78-1.71)]. VEs in which inflammation was resolved by Week 12 had lower FL prevalence at Weeks 48, 96 and 204 compared with VEs with unresolved inflammation. CONCLUSIONS: Early and sustained suppression of inflammation mitigates the risk of long-term FL development in the spine in study participants with axSpA evaluated over 4 years. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT01087762.

Feasibility of Intestinal MR Elastography in Inflammatory Bowel Disease.

BACKGROUND: While MR enterography allows detection of inflammatory bowel disease (IBD), the findings continue to be of limited use in guiding treatment-medication vs. surgery. PURPOSE: To test the feasibility of MR elastography of the gut in healthy volunteers and IBD patients. STUDY TYPE: Prospective pilot. POPULATION: Forty subjects (healthy volunteers: n = 20, 37 ± 14 years, 10 women; IBD patients: n = 20 (ulcerative colitis n = 9, Crohn's disease n = 11), 41 ± 15 years, 11 women). FIELD STRENGTH/SEQUENCE: Multifrequency MR elastography using a single-shot spin-echo echo planar imaging sequence at 1.5 T with drive frequencies of 40, 50, 60, and 70 Hz. ASSESSMENT: Maps of shear-wave speed (SWS, in m/s) and loss angle (φ, in rad), representing stiffness and solid-fluid behavior, respectively, were generated using tomoelastography data processing. Histopathological analysis of surgical specimens was used as reference standard in patients. STATISTICAL TESTS: Unpaired t-test, one-way analysis of variance followed by Tukey post hoc analysis, Pearson's correlation coefficient and area under the receiver operating characteristic curve (AUC) with 95%-confidence interval (CI). Significance level of 5%. RESULTS: MR elastography was feasible in all 40 subjects (100% technical success rate). SWS and φ were significantly increased in IBD by 21% and 20% (IBD: 1.45 ± 0.14 m/s and 0.78 ± 0.12 rad; healthy volunteers: 1.20 ± 0.14 m/s and 0.65 ± 0.06 rad), whereas no significant differences were found between ulcerative colitis and Crohn's disease (P = 0.74 and 0.90, respectively). In a preliminary assessment, a high diagnostic accuracy in detecting IBD was suggested by an AUC of 0.90 (CI: 0.81-0.96) for SWS and 0.84 (CI: 0.71-0.95) for φ. DATA CONCLUSION: In this pilot study, our results demonstrated the feasibility of MR elastography of the gut and showed an excellent diagnostic performance in predicting IBD. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

[Positive experiences of specialist assistants and physicians with respect to the delegation research project StaerkeR : Evaluation of the training and experiences within the framework of this project]. / Positive Erfahrungen von Fachassistent:innen und Ärzt:innen hinsichtlich des Delegations-Forschungsprojekts StärkeR : Evaluation der Schulung und Erfahrungen im Rahmen dieses Projekts.

INTRODUCTION: The delegation of medical services to rheumatology assistants (RFA) has proven to be safe and effective in the evaluation of the research project "StaerkeR". Afterwards, the experiences of the participating RFAs and rheumatologists with delegation were surveyed and discussed within the framework of an opinion research project. METHODS: At the end of the project, the participating RFAs and rheumatologists were surveyed via an online questionnaire (quantitative analysis) (21 questions for physicians and 44 questions for RFAs). In addition, focus group meetings were held for the RFAs, which were led by a moderator and a secretary. The results of the focus group sessions (qualitative analyses) were analyzed according to the structured method of Kuckartz. RESULTS: All 31 RFAs and 25 rheumatologists involved in the project participated in the online surveys and 9 RFAs took part in the 2 focus groups. In the online surveys, both the RFAs and the rheumatologists gave predominantly good to very good ratings with respect to RFA training, the implementation of delegation in the practices and outpatient clinics, the role of the RFAs and the overall evaluation of the delegation concept. In the focus group discussions, many possible limitations regarding acceptance and implementation of the delegation concept were mentioned. CONCLUSION: The delegation of medical tasks to RFAs is a concept that is positively assessed and highly accepted by both sides, the rheumatologists and the RFAs. In a comparison between the individual practices and hospital outpatient departments, there is still a clear heterogeneity with respect to the willingness and logistical possibilities in the implementation of the delegation concept.

Separation of fluid and solid shear wave fields and quantification of coupling density by magnetic resonance poroelastography.

PURPOSE: Biological soft tissues often have a porous architecture comprising fluid and solid compartments. Upon displacement through physiological or externally induced motion, the relative motion of these compartments depends on poroelastic parameters, such as coupling density ( ρ12 ) and tissue porosity. This study introduces inversion recovery MR elastography (IR-MRE) (1) to quantify porosity defined as fluid volume over total volume, (2) to separate externally induced shear strain fields of fluid and solid compartments, and (3) to quantify coupling density assuming a biphasic behavior of in vivo brain tissue. THEORY AND METHODS: Porosity was measured in eight tofu phantoms and gray matter (GM) and white matter (WM) of 21 healthy volunteers. Porosity of tofu was compared to values obtained by fluid draining and microscopy. Solid and fluid shear-strain amplitudes and ρ12 were estimated both in phantoms and in in vivo brain. RESULTS: T1 -based measurement of tofu porosity agreed well with reference values (R = 0.99, P < .01). Brain tissue porosity was 0.14 ± 0.02 in GM and 0.05 ± 0.01 in WM (P < .001). Fluid shear strain was found to be phase-locked with solid shear strain but had lower amplitudes in both tofu phantoms and brain tissue (P < .05). In accordance with theory, tofu and brain ρ12 were negative. CONCLUSION: IR-MRE allowed for the first time separation of shear strain fields of solid and fluid compartments for measuring coupling density according to the biphasic theory of poroelasticity. Thus, IR-MRE opens horizons for poroelastography-derived imaging markers that can be used in basic research and diagnostic applications.