Sacroiliac and spine imaging in spondyloarthritis: Does phenotype or sex matter?

BACKGROUND: Spondyloarthritis (SpA) encompasses a spectrum of immune-mediated inflammatory conditions primarily affecting the axial skeleton, including sacroiliitis and spondylitis, each with distinct features. This study aimed to investigate imaging disparities, focusing on sacroiliac magnetic resonance and spine radiography, across phenotypes and between males and females in axial SpA. METHOD: A cross-sectional study was conducted to assess clinical data, laboratory findings, magnetic resonance imaging (MRI) scores of sacroiliac joints using the Spondyloarthritis Research Consortium of Canada (SPARCC) and Sacroiliac Joint Structural Score (SSS), and cervical and lumbar spine radiographs utilizing the Modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The study aimed to compare these parameters between two groups: axial spondyloarthritis (axSpA, radiographic and non-radiographic) and axial psoriatic arthritis (axPsA), as well as between males and females. RESULTS: Ninety-four patients were included, with 62 patients in the axSpA group and 32 patients in the axPsA group. There were no differences in disease activity, mobility, radiographic damage in the spine (Modified Stoke Ankylosing Spondylitis Spine Score- mSASSS), or sacroiliac magnetic resonance imaging (MRI) scores (Spondyloarthritis Research Consortium of Canada Magnetic Resonance Imaging Index - SPARCC and Sacroiliac Joint Structural Score - SSS) between the two phenotypes. Regarding sex, in imaging exams, men had higher mSASSS (p = 0.008), SSS (p = 0.001), and fat metaplasia (MG) score based on SSS (p = 0.001), while women had significantly higher SPARCC scores (p = 0.039). In the male group, the presence of HLA-B27 allele had an impact on more structural lesions on MRI (SSS), p = 0.013. CONCLUSION: In this study, imaging of sacroiliac joints and spine in patients with axial SpA did not show differences in phenotypes but did reveal differences based on sex, which may have an impact on future diagnostic recommendations. Further studies are needed to confirm these findings.

Differences between radiographic and non-radiographic axial spondyloarthritis patients in a Mexican cohort.

To compare the demographic, clinical, and laboratory characteristics, disease onset, and clinical features of radiographic axial Spondyloarthritis (r-axSpA) and non-radiographic axial Spondyloarthritis (nr-axSpA) patients. All patients who attended outpatient spondylarthritis (SpA) clinics at Hospital General de Mexico and the Instituto Nacional de la Nutrición from 1998 to 2005 and met the rheumatologist diagnostic criteria for SpA were selected. Then the SpA patients were classified by European Spondyloarthropathy Study Group criteria (ESSG). We selected SpA patients with axial presentation as axial SpA (axSpA), and they were classified as r-axSpA if they met modified New York (mNY) criteria for sacroiliitis and as nr-axSpA if they did not meet mNY criteria; to compared clinical, demographic, and laboratory test between the subgroups. It included 148 SpA patients; 55 (37.2%) patients had r-axSpA, and 70 (47.3%) had nr-axSpA. The nr-axSpA patients had a lower proportion of males (58.6% vs 78.2%, P < 0.05), lower HLA-B27 frequency (54.3%. vs. 92.7%, P < 0.05), were older at disease onset (21 vs 16 years; P < 0.01) and had a higher frequency of infections at disease onset (9.1% vs 32.9, P < 0.05) than r-axSpA. BASFI (2.9 vs 4.8; P < 0.0001), Dougados functional index (7 vs. 14; P < 0.05), and BASDAI (4.1 vs. 5.2; P < 0.001) were lower in patients with nr-axSpA than r-axSpA, respectively. The factors that most influenced the presentation of r-axSpA were history of uveitis (OR 14, 95% CI 2.3-85), HLA-B27 (OR 7.97, 95% CI, 2.96-122), male sex (OR 6.16, 95% CI, 1.47-25.7), axial enthesopathy count (OR 1.17 95% CI, 1.03-1.33). This study provides insight into the differences between nr-axSpA and r-axSpA in Mexico. Patients with r-axSpA were mainly male, with a younger presentation age, a higher prevalence of HLA-B27, more history of uveitis, fewer episodes of dactylitis, more axial enthesopathy, and higher disease activity than nr-axSpA.

Reduced expression of miRNAs as potential biomarkers in axial spondyloarthritis.

OBJECTIVE: This study aimed to investigate the value of miR-29a-3p, miR-27a, miR126-3p, miR-146a-5p, miR-625-3p, miR-130a, miR-32, miR-218, miR-131, and miR5196 in the diagnosis of axial spondyloarthritis and to determine whether there is a difference in miRNA expression levels between radiographic axial spondyloarthritis and non-radiographic axial spondyloarthritis, as well as the relationship between miRNA expression levels, disease activity, and uveitis history. METHODS: This study included 50 patients with axial spondyloarthritis (25 with radiographic axial spondyloarthritis and 25 with non-radiographic axial spondyloarthritis) and 25 healthy individuals. The fold change of miRNA expression for each miRNA was calculated using the 2-ΔΔCt method. RESULTS: The expression of all miRNAs except miR-130a was downregulated in axial spondyloarthritis patients (miR-27a: fold regulation: -11.21, p<0.001; miR-29a-3p: fold regulation: -2.63, p<0.001; miR-32: fold regulation: -2.94, p=0.002; miR-126-3p: fold regulation -10.94, p<0.001; miR-132: fold regulation: -2.18, p<0.001; miR-146-5p: fold regulation: -9.78, p<0.001; miR-218: fold regulation: -2.65, p<0.001; miR-625-3p: fold regulation: -2.01, p=0.001; miR-5196-3p: fold regulation: -7.04, p<0.001). The expression levels of these miRNAs did not differ significantly between non-radiographic axial spondyloarthritis and radiographic axial spondyloarthritis patients (p>0.05 for all). CONCLUSION: Particularly, miR-27a, miR-126-3p, miR-146-5p, and miR-5196-3p were found to be substantially downregulated in both non-radiographic axial spondyloarthritis and radiographic axial spondyloarthritis patients, suggesting their potential as diagnostic biomarkers for axial spondyloarthritis.

Prevalence of spondyloarthritis in inflammatory bowel disease according ASAS and ultrassonography and its correlation with plasma calprotectin.

BACKGROUND: Enteropathic spondyloarthritis is underdiagnosed and inflammatory biomarkers and ultrasonography (US) could be useful for screening inflammatory bowel disease (IBD) patients. The objective of this study was to evaluate the prevalence of spondyloarthritis (SpA) in IBD patients, according to the Assessment of SpondyloArthritis International Society (ASAS) criteria and the correlation of results of US of entheses and joints with plasma calprotectin levels. METHODS: This was an observational cross-sectional study. Patients from the IBD outpatient clinic of a reference center were evaluated according to ASAS criteria classification, results of US of entheses and joints, and inflammatory biomarker measurements (erythrocyte sedimentation rates, C-reactive protein levels, fecal and plasma calprotectin levels). A p value lower than 0.05 was considered significant. RESULTS: A total of 30.5% of the studied sample (n = 118) of patients with IBD presented at least one inflammatory musculoskeletal manifestation. The overall prevalence of enteropathic SpA was 13.55%, with 10.16% axial SpA and 4.23% peripheral SpA according to the ASAS criteria. A total of 42.1% of patients had an MASEI score greater than 18, 35.2% had synovitis, and 14.7% had tenosynovitis on US, increasing the frequency of diagnosis of enteropathic SpA to 22.8%. Plasma calprotectin levels were similar to those in healthy controls, and correlated only with the fecal calprotectin level (p 0.041). CONCLUSIONS: A total of 13.5% of patients met the criteria in accordance with the ASAS criteria for enteropathic SpA, which increased to 22.8% with the addition of US. The prevalence of enthesitis, synovitis and tenosynovitis by US of symptomatic joints and entheses were 42%, 35% and 14.7% respectively. Plasma calprotectin was correlated with fecal calprotectin but not with inflammatory biomarkers or US or ASAS criteria.

Assessment of enthesopathy in conventional pelvis radiography: Another tool for spondyloarthritis diagnosis beyond sacroiliitis.

INTRODUCTION/OBJECTIVES: Enthesitis is a cardinal feature of spondylarthritis (SpA), and the pelvis is a common site of enthesitis. This study aimed to establish the association between pelvic enthesis involvement on pelvic X-ray and SpA diagnosis through a radiographic enthesis index (REI) and to assess the reliability and accuracy of this REI. MATERIALS AND METHODS: The participants were SpA patients and a control group composed of patients with chronic lumbar pain without SpA. Three blinded observers assessed each pelvic radiography three times. Three zones were used: Zone I (ZI), the iliopubic ramus; Zone II (ZII), the pubic symphysis, and Zone III (ZIII), the ischiopubic ramus. A grading system was created from 0 to 3 [Grade 0, normal; Grade 1, minimal changes (subcortical bone demineralization and/or periosteal wishkering, seen as radiolucency and trabeculation of the cortical bone upon tendon insertion); Grade 2, destructive changes (Grade 1 findings and erosions at the enthesis site); and Grade 3, findings of Grade 2 plus >2 mm whiskering out of the cortical bone) for the REI. The sum of the results of the three zones was called the total REI. For statistical analysis, we used the weighted kappa statistic adjusted for prevalence and bias using Gwet's agreement coefficient. RESULTS: We enrolled 161 patients, 111 of them with SpA (39.6 % with axial SpA and 47.7 % with peripheral SpA) and 50 without SpA. In the SpA group, 36.7 % and 25.7 % had REI Grades 2 and 3 in ZIII, respectively, while only 6 % of the controls had these grades. For ZI, the frequency of Grades 1 to 3 was 42.3 % in the SpA group (8.1 %, 14.4 %, and 19.8 %, respectively), compared to only 2 % in the controls. ZII was unaffected in most of the patients with SpA (82.9 %) and in the controls (98 %). In the control group, Grade 0 was the most common REI grade in all three zones. The agreement was almost perfect for each zone and between the independent readers. The ROC-curve analysis showed that the highest performance areas were the total REI, ZIII, and ZI. Most (75 %) of the SpA patients without sacroiliitis on X-ray were REI-positive. The sensitivity of the REI for SpA diagnosis was 82 %, while the sensitivity of sacroiliitis on X-ray was 38.7 %. CONCLUSIONS: The assessment of pelvic enthesis using the REI on pelvic radiography may be useful for SpA diagnosis. Total REI, ZIII, and ZI had the highest accuracy and almost perfect reliability. The REI is especially helpful in patients without sacroiliitis on imaging.

Non-radiographic axial spondyloarthritis in South America. Burden of disease and differential features with respect to ankylosing spondylitis at time of diagnosis. A comprehensive analysis with a focus on images.

BACKGROUND: Non-radiographic axial spondyloarthritis (nr-axSpA) data from South America are scarce, especially regarding image features. Objective To estimate the frequency of nr-axSpA and ankylosing spondylitis (AS) in a cohort of Argentinian patients with chronic low back pain (LBP) and to analyze the difference between both, with focus on magnetic resonance imaging (MRI) lesions, at diagnosis. METHODS: Patients with LBP and a diagnosis of axSpA who participated in a reuma-check program were included. All patients with a suspicion of SpA were evaluated using blood analytics, HLA-B27, and images (MRI). Sociodemographic data, SpA features, diagnostic dela,y and clinimetrics were assessed by an operator who was blinded to the patient's test results. On MRI, the presence of SpA lesions was assessed and a concordance exercise was carried out between rheumatologists and radiologist. RESULT: Of 198 LBP patients, 97 had axSpA, 54% of whom were nr-axSpA. A positive MRI was found in 50%. No difference in terms of disease activity, functional impact, laboratory or treatments between nr-axSpA and AS were found. Higher frequencies of male sex and chronic lesions on sacroiliac MRI were found in AS patients. In the logistic regression, an independent association with AS diagnosis was found: male (odds ratio [OR] 4.8), MRI fat replacement (OR 4.6), MRI sclerosis (OR 7.6), and diagnostic delay of more than 2 years (OR 10). The concordance between rheumatologists and radiologists was considered good to very good (κ 0.7-0.8). CONCLUSION: The frequency of nr-axSpA was 54%. We found a higher frequency of being male, more SpA features, and a longer diagnostic delay in patients with AS. Patients with AS had more structural lesions, with a good concordance between rheumatologist and radiologist.

Radiomic Quantification for MRI Assessment of Sacroiliac Joints of Patients with Spondyloarthritis.

Spondyloarthritis (SpA) is a group of diseases primarily involving chronic inflammation of the spine and peripheral joints, as evaluated by magnetic resonance imaging (MRI). Considering the complexity of SpA, we performed a retrospective study to discover quantitative/radiomic MRI-based features correlated with SpA. We also investigated different fat-suppression MRI techniques to develop detection models for inflammatory sacroiliitis. Finally, these model results were compared with those of experienced musculoskeletal radiologists, and the concordance level was evaluated. Examinations of 46 consecutive patients were obtained using SPAIR (spectral attenuated inversion recovery) and STIR (short tau inversion recovery) MRI sequences. Musculoskeletal radiologists manually segmented the sacroiliac joints for further extraction of 230 MRI features from gray-level histogram/matrices and wavelet filters. These features were associated with sacroiliitis, SpA, and the current biomarkers of ESR (erythrocyte sedimentation rate), CRP (C-reactive protein), BASDAI (Bath Ankylosing Spondylitis Activity Index), BASFI (Bath Ankylosing Spondylitis Functional Index), and MASES (Maastricht Ankylosing Spondylitis Enthesis Score). The Mann-Whitney U test showed that the radiomic markers from both MRI sequences were associated with active sacroiliitis and with SpA and its axial and peripheral subtypes (p < 0.05). Spearman's coefficient also identified a correlation between MRI markers and data from clinical practice (p < 0.05). Fat-suppression MRI models yielded performances that were statistically equivalent to those of specialists and presented strong concordance in identifying inflammatory sacroiliitis. SPAIR and STIR acquisition protocols showed potential for the evaluation of sacroiliac joints and the composition of a radiomic model to support the clinical assessment of SpA.

Brazilian recommendations for the use of nonsteroidal anti-inflammatory drugs in patients with axial spondyloarthritis.

Spondyloarthritis (SpA) is a group of chronic inflammatory systemic diseases characterized by axial and/or peripheral joints inflammation, as well as extra-articular manifestations. Over some decades, nonsteroidal anti-inflammatory drugs (NSAIDs) have been the basis for the pharmacological treatment of patients with axial spondyloarthritis (axSpA). However, the emergence of the immunobiologic agents brought up the discussion about the role of NSAIDs in the management of these patients. The objective of this guideline is to provide recommendations for the use of NSAIDs for the treatment of axSpA. A panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis of randomized clinical trials for 15 predefined questions. The Grading of Recommendations, Assessment, Development and Evaluation methodology to assess the quality of evidence and formulate recommendations were used, and at least 70% agreement of the voting panel was needed. Fourteen recommendations for the use of NSAIDs in the treatment of patients with axSpA were elaborated. The purpose of these recommendations is to support clinicians' decision making, without taking out his/her autonomy when prescribing for an individual patient.

A study of MRI-based radiomics biomarkers for sacroiliitis and spondyloarthritis.

PURPOSE: To evaluate the performance of texture-based biomarkers by radiomic analysis using magnetic resonance imaging (MRI) of patients with sacroiliitis secondary to spondyloarthritis (SpA). RELEVANCE: The determination of sacroiliac joints inflammatory activity supports the drug management in these diseases. METHODS: Sacroiliac joints (SIJ) MRI examinations of 47 patients were evaluated. Thirty-seven patients had SpA diagnoses (27 axial SpA and ten peripheral SpA) which was established previously after clinical and laboratory follow-up. To perform the analysis, the SIJ MRI was first segmented and warped. Second, radiomics biomarkers were extracted from the warped MRI images for associative analysis with sacroiliitis and the SpA subtypes. Finally, statistical and machine learning methods were applied to assess the associations of the radiomics texture-based biomarkers with clinical outcomes. RESULTS: All diagnostic performances obtained with individual or combined biomarkers reached areas under the receiver operating characteristic curves ≥ 0.80 regarding SpA related sacroiliitis and and SpA subtypes classification. Radiomics texture-based analysis showed significant differences between the positive and negative SpA groups and differentiated the axial and peripheral subtypes (P < 0.001). In addition, the radiomics analysis was also able to correctly identify the disease even in the absence of active inflammation. CONCLUSION: We concluded that the application of the radiomic approach constitutes a potential noninvasive tool to aid the diagnosis of sacroiliitis and for SpA subclassifications based on MRI of sacroiliac joints.

Machine learning techniques for computer-aided classification of active inflammatory sacroiliitis in magnetic resonance imaging.

BACKGROUND: Currently, magnetic resonance imaging (MRI) is used to evaluate active inflammatory sacroiliitis related to axial spondyloarthritis (axSpA). The qualitative and semiquantitative diagnosis performed by expert radiologists and rheumatologists remains subject to significant intrapersonal and interpersonal variation. This encouraged us to use machine-learning methods for this task. METHODS: In this retrospective study including 56 sacroiliac joint MRI exams, 24 patients had positive and 32 had negative findings for inflammatory sacroiliitis according to the ASAS group criteria. The dataset was randomly split with ~ 80% (46 samples, 20 positive and 26 negative) as training and ~ 20% as external test (10 samples, 4 positive and 6 negative). After manual segmentation of the images by a musculoskeletal radiologist, multiple features were extracted. The classifiers used were the Support Vector Machine, the Multilayer Perceptron (MLP), and the Instance-Based Algorithm, combined with the Relief and Wrapper methods for feature selection. RESULTS: Based on 10-fold cross-validation using the training dataset, the MLP classifier obtained the best performance with sensitivity = 100%, specificity = 95.6% and accuracy = 84.7%, using 6 features selected by the Wrapper method. Using the test dataset (external validation) the same MLP classifier obtained sensitivity = 100%, specificity = 66.7% and accuracy = 80%. CONCLUSIONS: Our results show the potential of machine learning methods to identify SIJ subchondral bone marrow edema in axSpA patients and are promising to aid in the detection of active inflammatory sacroiliitis on MRI STIR sequences. Multilayer Perceptron (MLP) achieved the best results.

The Brazilian Society of Rheumatology guidelines for axial spondyloarthritis - 2019.

Spondyloarthritis is a group of chronic inflammatory systemic diseases characterized by axial and/or peripheral joints inflammation, as well as extra-articular manifestations. The classification axial spondyloarthritis is adopted when the spine and/or the sacroiliac joints are predominantly involved. This version of recommendations replaces the previous guidelines published in May 2013.A systematic literature review was performed, and two hundred thirty-seven studies were selected and used to formulate 29 recommendations answering 15 clinical questions, which were divided into four sections: diagnosis, non-pharmacological therapy, conventional drug therapy and biological therapy. For each recommendation the level of evidence supporting (highest available), the strength grade according to Oxford, and the degree of expert agreement (inter-rater reliability) is informed.These guidelines bring evidence-based information on clinical management of axial SpA patients, including, diagnosis, treatment, and prognosis.

Ultrasound of sacroiliac joints in spondyloarthritis: a systematic review.

Ultrasound (US) is an accessible imaging technique with a possible role to diagnose active sacroiliitis, so this technique is projected as a promising diagnostic tool for the diagnosis of SpA. We analyse the available evidence about the use of US as a diagnostic tool in sacroiliitis in patients with SpA, by a systemic review of the literature fulfilling OMERACT criteria. A systematic literature search for original articles was carried out using four databases (Medline, Embase, Scopus and Web of Science). Data from studies were included only if participants had SpA and a US examination of sacroiliac joint (SIJ) was performed. The methodological quality of the studies was assessed using QUADAS-2 tool. Thirteen studies were included. All studies were observational, prospective and cross-sectional. In most articles (76.9%), the main US finding compatible with sacroiliitis evaluated was the presence of vascularisation (Doppler signals) with measurements of the resistive index (RI). The sensitivity and specificity analysis were performed in seven studies (58.8%) and were good, with a median of 90 and 89.2%, respectively. The studies showed a positive to moderate a strong correlation between the US and the gold standard but this was optimal only in four studies. In general, the agreement was good in all studies (≥ 0.80). The methods of evaluation of sacroiliitis vary between the studies included. To date, there is not enough evidence to support the use of ultrasound as a diagnostic method for sacroiliitis but it has potential to identify structural lesions at SIJ's level.

Performance of the classification criteria in patients with late-onset axial spondyloarthritis.

AIM: To evaluate the performance of four different classification criteria for spondyloarthritis (SpA) in patients with late-onset symptoms and to compare the clinical, laboratory and radiographic outcomes among the patients with symptoms before and after 45 years of age. PATIENTS AND METHODS: A total of 329 patients with SpA were enrolled in this prospective cohort. Patients with psoriatic arthritis, reactive arthritis, colitis associated arthritis and peripheral or undifferentiated SpA were excluded. The remaining individuals were divided into two groups based on their ages at the time of onset of symptoms: from 16 to 45 years of age (adult-onset, A-O) and after 45 years of age (late-onset, L-O). The clinical data were collected, including BASDAI, BASFI, BASMI, mSASSS, ASDAS, as were concomitant diseases and medications, efficacy and safety data. The performance of four SpA classification criteria, including modified New York, ESSG, Amor and ASAS, was evaluated in both groups. p value <.05 was considered as significant. RESULTS: Thirty-two patients (9.72%) had L-O axial SpA. Mean age of diagnosis and symptoms were 57.6 (8.0) years and 7.6 (5.1) years, respectively. L-O patients had statistically worse functional impairment and higher disease activity. However, they had lower radiographic sacroiliac and spine damage (p < .001). CONCLUSION: Our data showed that almost 10% of the patients with SpA had late-onset of symptoms. Moreover, they had higher disease activity, worse physical function and lower spine radiographic damage than A-O SpA patients. Additionally, the ASAS classification criteria had the best performance and might be used in clinical practice.

Topographic MRI evaluation of the sacroiliac joints in patients with axial spondyloarthritis.

OBJECTIVE: To evaluate the imaging features of spondyloarthritis in magnetic resonance imaging (MRI) of the sacroiliac (SI) joint and topography (in thirds) and affected margin, considering that this issue is rarely addressed in the literature. METHODS: A cross-sectional study evaluating MRI (1.5T) of SI in 16 patients with axial spondyloarthritis, for the presence of acute (subchondral bone edema, enthesitis, synovitis and capsulitis) and chronic (erosions, subchondral bone sclerosis, bony bridges, and fatty infiltration) changes, performed by two blinded radiologists. MRI findings were correlated with clinical data, including age, duration of disease, medications, HLA-B27, BASDAI, ASDAS-ESR and ASDAS-CRP, BASMI, BASFI, and mSASSS. RESULTS: Bone edema pattern and erosions were predominant in the upper third of SI (p=0.050 and p=0.0014, respectively). There was a correlation between disease duration and structural changes by affected third (p=0.028-0.037), as well as between the presence of bone bridges with BASMI (p=0.028) and mSASSS (p=0.014). Patients with osteitis in the lower third showed higher values for ASDAS (ESR: p=0.011 and PCR: p=0.017). CONCLUSION: Chronic inflammatory changes and the pattern of bone edema predominated in the upper third of SI, but a simultaneous involvement of middle or lower thirds of the joint was also noted. The location of involvement in the upper third of SI is insufficient to differentiate between degeneration and inflammation.

Topographic MRI evaluation of the sacroiliac joints in patients with axial spondyloarthritis / Avaliação topográfica das articulações sacroilíacas por ressonância magnética em pacientes com espondiloartrite axial

Abstract Objective: To evaluate the imaging features of spondyloarthritis in magnetic resonance imaging (MRI) of the sacroiliac (SI) joint and topography (in thirds) and affected margin, considering that this issue is rarely addressed in the literature. Methods: A cross-sectional study evaluating MRI (1.5 T) of SI in 16 patients with axial spondyloarthritis, for the presence of acute (subchondral bone edema, enthesitis, synovitis and capsulitis) and chronic (erosions, subchondral bone sclerosis, bony bridges, and fatty infiltration) changes, performed by two blinded radiologists. MRI findings were correlated with clinical data, including age, duration of disease, medications, HLA-B27, BASDAI, ASDAS-ESR and ASDAS-CRP, BASMI, BASFI, and mSASSS. Results: Bone edema pattern and erosions were predominant in the upper third of SI (p = 0.050 and p = 0.0014, respectively). There was a correlation between disease duration and structural changes by affected third (p = 0.028-0.037), as well as between the presence of bone bridges with BASMI (p = 0.028) and mSASSS (p = 0.014). Patients with osteitis in the lower third showed higher values for ASDAS (ESR: p = 0.011 and PCR: p = 0.017). Conclusion: Chronic inflammatory changes and the pattern of bone edema predominated in the upper third of SI, but a simultaneous involvement of middle or lower thirds of the joint was also noted. The location of involvement in the upper third of SI is insufficient to differentiate between degeneration and inflammation.

Resumo Objetivo: Avaliar as características de imagem das espondiloartrites na ressonância magnética (RM) das articulações sacroilíacas (SI) quanto à topografia (em terços) e margem acometida, uma vez que esse aspecto é pouco abordado na literatura. Métodos: Estudo transversal com avaliação por RM (1,5 T) das SI em 16 pacientes com diagnóstico de espondiloartrite axial quanto à presença de alterações agudas (edema ósseo subcondral, entesite, sinovite e capsulite) e crônicas (erosões, esclerose óssea subcondral, ponte óssea e substituição gordurosa), feita por dois radiologistas, cegos para os dados clínicos. Os achados da RM foram correlacionados com dados clínicos, incluindo idade, tempo de doença, medicações, HLA-B27, BASDAI, ASDAS-VHS e ASDAS-PCR, BASMI, BASFI e mSASSS. Resultados: Padrão de edema ósseo e erosões apresentaram predomínio no terço superior das SI (p = 0,050 e p = 0,0014, respectivamente). Houve correlação entre o tempo de doença e alterações estruturais por terço acometido (p = 0,028-0,037), bem como a presença de pontes ósseas com o BASMI (p = 0,028) e o mSASSS (p = 0,014). Pacientes com osteíte no terço inferior apresentaram maiores valores de ASDAS (VHS: p = 0,011 e PCR: p = 0,017). Conclusão: As alterações inflamatórias crônicas e o padrão de edema ósseo predominaram no terço superior das SI, mas também havia acometimento concomitante dos terços médio ou inferior da articulação. A localização do acometimento no terço superior das SI se mostra insuficiente para a diferenciação entre degeneração e inflamação.

Ultrasonography assessment of heel entheses in patients with spondyloarthritis: a comparative study with magnetic resonance imaging and conventional radiography.

The aim of the present study was to determine the agreement between ultrasonography (US), magnetic resonance imaging (MRI), and conventional radiography (CR) in the detection of findings indicative of enthesopathy in spondyloarthritis (SpA) patients. A cross-sectional study was performed in 40 SpA patients. Heel entheses (Achilles tendon and plantar fascia) were bilaterally examined by US, MRI, and CR. The three imaging modalities were carried out by three independent operators blinded to the other imaging modality data. Soft tissue abnormalities indicative of enthesopathy as thickening, structural changes, and bursitis were assessed by both US and MRI, and cortical bone abnormalities indicative of enthesopathy as erosions and enthesophytes were assessed by the three imaging modalities. The unweighted kappa values between US and MRI were 0.80, 0.66, 0.69, 0.70, and 0.70 for thickening, structural changes, bursitis, enthesophytes, and bone erosions, respectively. With respect to the detection of enthesophytes, the unweighted kappa values between CR and both US and MRI were 0.78 and 0.76, respectively. At last, for the recognition of bone erosions, the unweighted kappa values between CR and both US and MRI were 0.38 and 0.45, respectively. Using MRI as standard reference method, US was more sensitive with respect to CR revealing bone erosions. The present study provides evidence about the high overall agreement between US and MRI for all abnormal comparable findings at entheseal level and between US, MRI, and CR for the detection of enthesophytes in SpA patients.

MRI assessment of bone marrow oedema in the sacroiliac joints of patients with spondyloarthritis: is the SPAIR T2w technique comparable to STIR?

OBJECTIVE: To compare short tau inversion-recovery (STIR) with another fat saturation method in the assessment of sacroiliac joint inflammation. METHODS: This prospective cross-sectional study comprised 76 spondyloarthritis (SpA) patients who underwent magnetic resonance imaging of the sacroiliac joints in a 1.5-T scanner, using STIR, spectral attenuated inversion recovery (SPAIR) T2w and spectral presaturation with inversion recovery (SPIR) T1w post-contrast sequences. Two independent readers (R1 and R2) assessed the images using the Spondyloarthritis Research Consortium of Canada (SPARCC) score. We assessed agreement of the SPARCC scores for SPAIR T2w and STIR with that for T1 SPIR post-contrast (reference standard) using the St. Laurent coefficient. We evaluated each sequence using the concordance correlation coefficient (CCC). RESULTS: We observed a strong agreement between STIR and SPAIR T2w sequences. Lin's CCC was 0.94 for R1 and 0.84 for R2 for STIR and 0.94 for R1 and 0.84 for R2 for SPAIR. The interobserver evaluation revealed a good CCC of 0.79 for SPAIR and 0.78 for STIR. CONCLUSION: STIR technique and SPAIR T2w sequence showed high agreement in the evaluation of sacroiliac joint subchondral bone marrow oedema in patients with SpA. SPAIR T2w may be an alternative to the STIR sequence for this purpose. KEY POINTS: • There are no studies evaluating which fat saturation technique should be used. • SPAIR T2w may be an alternative to STIR for sacroiliac joint evaluation. • The study will lead to changes in guidelines for spondyloarthritis.

Factors associated with the decision of the rheumatologist to order sacroiliac joints magnetic resonance imaging (SI-MRI) or HLA-B27 testing in the diagnostic work-up of patients with spondyloarthritis in clinical practice.

OBJECTIVES: To evaluate the patients' characteristics associated with the clinical decision to request SI-MRI and/or HLA-B27 in patients with SpA in daily practice. METHODS: Patients referred to a rheumatology outpatient-clinic in a national referral-centre were selected. Patients with a clinical diagnosis of SpA according to the rheumatologist were included. SI-MRI and HLA-B27 was available for patients in whom the rheumatologists had ordered these tests. Characteristics associated with ordering SI-MRI or HLA-B27 were identified with univariable analyses. Variables with p-value <0.05 and >80% completeness were selected for further analysis. A multivariable logistic regression analysis was used to evaluate the determinants related with the decision to perform SI-MRI and/or HLA-B27 and odds ratios with 95% confidence intervals were calculated. RESULTS: In total, 581 patients with SpA were included in the cohort, 72% were men, mean age 34.6±12.1 and disease duration 7.3±9.7 years. Of these patients, 24% (n=137) had SI-MRI and 77% (n=441) had HLA-B27 tests ordered. Independently predictive factors for ordering a SI-MRI were the presence of IBP (OR=1.81), enthesitis (OR=1.57) and the number of initial-symptoms at presentation (OR=1.27 per additional symptom present). Independently predictive factors of HLA-B27 testing were the number of initial-symptoms (OR=1.45 per symptom) and uveitis (OR=3.19). CONCLUSIONS: This study strongly suggests that rheumatologists use certain clinical clues to decide if they order expensive and scarce tests in the diagnostic work-up of SpA patients. These manifestations may increase the efficiency of these tests in clinical practice and suggest that clinical reasoning follows principles of Bayesian theory.

Espondiloartritis anquilosante: revisión de hallazgos imagenológicos en la columna / Ankylosing spondyloarthritis: review of spinal imaging findings

Abstract: Introduction. Ankylosing spondyloarthritis (AS) is the most common and representative of seronegative spondyloarthropathy. It is characterised by chronic inflammation of the axial skeleton, leading to chronic back pain and progressive stiffness. It typically occurs in young patients, with symptoms often appearing with peak onset between 20 and 30 years of age, and is strongly associated with human leukocyte antigen B-27 (HLA B-27). Current imaging techniques are central in the management of these patients. The recognition of its classic imaging findings and its complications is essential for radiologists. Objectives. To present a pictorial review of the spinal imaging findings in patients with AS. Methods and materials. An analysis will be made of the spinal imaging findings in conventional radiography, CT and MRI in multiple patients from our medical centre. The most representative findings, complications, differential diagnoses, and some radiological key points will be shown.

Resumen: Introducción. La espondilitis anquilosante (EA) es la artropatía seronegativa más común y representativa. Se caracteriza por inflamación crónica del esqueleto axial, dolor referido a la columna vertebral de tipo inflamatorio y rigidez progresiva. Típicamente se manifiesta en pacientes jóvenes que inician su sintomatología entre los 20-30 años de edad y está ligada al antígeno leucocitario humano B-27 (HLA B-27). Las imágenes son fundamentales en el manejo de estos pacientes. Es deber del radiólogo reconocer los hallazgos imagenológicos presentes. Objetivos. Realizar una revisión pictográfica de hallazgos imagenológicos presentes en la columna vertebral de pacientes portadores de EA. Material y método. Análisis de las manifestaciones imagenológicas de columna más representativas de la EA en pacientes de nuestro centro en radiografía convencional, TC y RM, junto con posibles complicaciones y diagnósticos diferenciales.

Use of (99m)Tc-anti-TNF-α scintigraphy in a patient with non-radiographic axial spondyloarthritis.

The aim of this study was to describe the use of (99m)Tc-anti-TNF-α scintigraphy for detecting inflammation of the sacroiliac joints in a patient with non-radiographic axial spondyloarthritis. A 47-year-old female patient, non-smoker and non-drinker, complained of a low back pain inflammation, which began 4 years before her condition have exacerbated to morning stiffness and anterior uveitis in the last 6 months. Initially diagnosed as mechanical low back pain, she irregularly took non-steroidal anti-inflammatory drugs and corticosteroids, without significant long-lasting results. Radiographic findings were negative. There was increased uptake of (99m)Tc-anti-TNF-α in an area corresponding to the topography of ileum and sacroiliac right joint upon (99m)Tc-anti-TNF-α scintigraphy. Magnetic resonance imaging (MRI), the most used image diagnosis tool, showed minimum impregnation of gadolinium in the right sacroiliac joint and at the iliac face of the inferior third of the right sacroiliac joint. We suggest that (99m)Tc-anti-TNF-α can facilitate early diagnosis of patients with non-radiographic axial spondyloarthritis. More studies are now ongoing.