Diagnostic performance of sacroiliac and spinal MRI for the diagnosis of non-radiographic axial spondyloarthritis in patients with inflammatory back pain

Knowledge, Attitudes, and Practices of Moroccan Community Rheumatologists' Regarding the Management of Non-radiographic Axial Spondyloarthritis: A National Cross-Sectional Study

Introduction Non-radiographic axial spondyloarthritis (nr-axSpA) is within the spectrum of axial spondyloarthritis (axSpA). The emergence of the nr-axSpA concept, defined by the absence of significant erosive damage to the sacroiliac joints, has prompted numerous initiatives aimed at enhancing the early detection and management of this condition. The aim of the study was to assess the knowledge, attitudes, and practices related to the diagnosis and management of nr-axSpA by rheumatologists in Morocco. Methods We conducted a cross-sectional online survey among the rheumatologist community in Morocco. Rheumatologists received via e-mail a structured Google Forms (Google Inc., Mountainview, CA) questionnaire divided into four sections: sociodemographic data of rheumatologists, knowledge, attitudes, and practices related to the diagnosis and treatment management of nr-axSpA. Results A total of 110 rheumatologists (mean age of 44±13 years, 77.3% females, median professional experience of 12 years (4, 75; 26.25 years)) participated in the survey (response rate of 25%). Most responders reported a diagnosis delay issue in spondyloarthritis (SpA) (93.6%); 70.9% of rheumatologists incorrectly regarded the 2009 Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axSpA as diagnostic criteria. Rheumatologists' awareness of recommended magnetic resonance imaging (MRI) sequences for detecting sacroiliac joint inflammation and structural changes in SpA varied significantly, from 69.1% to 14.5%. Their knowledge of additional subchondral edema cases in these joints, beyond SpA, ranged from 48.2% to 87.3%. Almost all rheumatologists believed that the use of sacroiliac MRI would contribute to the early diagnosis of axSpA (97.3%) but could also lead to false positive diagnoses, according to 47.3% of rheumatologists; 73.6% believed that incorrectly using the 2009 ASAS classification criteria as diagnostic criteria in nr-axSpA could also result in false-positive diagnoses. In their practice, 2009 ASAS classification criteria were used as diagnostic criteria in axSpA by 39.1% of rheumatologists. Of the total participants, 91.8% indicated that they approach nr-axSpA similarly to radiographic axial spondyloarthritis, with disparities in recommendations of biological therapies. Conclusion Our survey provides insight into the current status of nr-axSpA management among Moroccan rheumatologists. It also addresses concerns regarding the risk of false positive diagnoses when using the 2009 ASAS classification criteria for axSpA as diagnostic criteria by rheumatologists and the potential risk of misdiagnosis associated with excessive reliance on MRI, despite its utility for early diagnosis.

Effects of disease-modifying anti-rheumatic drugs on sacroiliac MRI score in axial spondyloarthritis: a systematic review and meta-analysis

INTRODUCTION

Sacroiliac bone marrow edema is an important factor in the diagnosis and management of axial spondyloarthritis (axSpA). The aim of this meta-analysis is to assess the effect of the different bDMARDs and tsDMARDs on the SPARCC score at 12-16 and 48-52 weeks.

METHODS

A systematic review, performed on PubMed (including Medline), Cochrane (CENTRAL) and DOAJ databases, included randomized controlled studies evaluating the sacroiliac joint (SIJ) SPARCC score at 12-16 or 48-52 weeks in patients with axSpA meeting the ASAS 2009 criteria or the modified New York criteria. We included studies evaluating the effects of the different treatments on the SPARCC score of SIJ in axial spondyloarthritis in comparison to a control group.

RESULTS

Eighteen studies were included in the meta-analysis. Nine studies evaluated the effect of TNFα inhibitors (TNFi), three for IL-17 inhibitors, and four for JAK inhibitors. At 12 and 16 weeks, SIJ SPARCC score was significantly improved by TNFi (WMD: - 3.29 [95% CI - 4.25; - 2, 34]), by IL-17 inhibitors (WMD: - 4.66 [95% CI - 6.22; - 3.09]), and by JAK inhibitors (JAKi) (WMD: - 3.06 [95% CI - 3.24; - 2.89]). There was no difference between the molecule subgroups. At 48-52 weeks, TNFα inhibitors reduced more SIJ SPARCC, but not significantly (WMD: - 2.26 [95% CI - 4.94; 0.42]), than placebo groups who began a TNFi treatment with delay.

CONCLUSION

Our meta-analysis shows a comparable improvement of the SIJ SPARCC score regarding TNFi, JAKi, and IL-17 inhibitors at three months and suggests the presence of an opportunity window. Key Points • Anti-TNF Ab, anti-IL17 Ab, and JAK inhibitor treatments reduce the sacroiliac joint SPARCC scores. • There is no difference between the different treatments in the reduction of the sacroiliac joint SPARCC score after 3 months in axial spondyloarthritis.

Research on automatic recognition radiomics algorithm for early sacroiliac arthritis based on sacroiliac MRI imaging

OBJECTIVE

To create an automated machine learning model using sacroiliac joint MRI imaging for early sacroiliac arthritis detection, aiming to enhance diagnostic accuracy.

METHODS

We conducted a retrospective analysis involving 71 patients with early sacroiliac arthritis and 85 patients with normal sacroiliac joint MRI scans. Transverse T1WI and T2WI sequences were collected and subjected to radiomics analysis by two physicians. Patients were randomly divided into training and test groups at a 7:3 ratio. Initially, we extracted the region of interest on the sacroiliac joint surface using ITK-SNAP 3.6.0 software and extracted radiomic features. We retained features with an Intraclass Correlation Coefficient > 0.80, followed by filtering using max-relevance and min-redundancy (mRMR) and LASSO algorithms to establish an automatic identification model for sacroiliac joint surface injury. Receiver operating characteristic (ROC) curves were plotted, and the area under the ROC curve (AUC) was calculated. Model performance was assessed by accuracy, sensitivity, and specificity.

RESULTS

We evaluated model performance, achieving an AUC of 0.943 for the SVM-T1WI training group, with accuracy, sensitivity, and specificity values of 0.878, 0.836, and 0.943, respectively. The SVM-T1WI test group exhibited an AUC of 0.875, with corresponding accuracy, sensitivity, and specificity values of 0.909, 0.929, and 0.875, respectively. For the SVM-T2WI training group, the AUC was 0.975, with accuracy, sensitivity, and specificity values of 0.933, 0.889, and 0.750. The SVM-T2WI test group produced an AUC of 0.902, with accuracy, sensitivity, and specificity values of 0.864, 0.889, and 0.800. In the SVM-bimodal training group, we achieved an AUC of 0.974, with accuracy, sensitivity, and specificity values of 0.921, 0.889, and 0.971, respectively. The SVM-bimodal test group exhibited an AUC of 0.964, with accuracy, sensitivity, and specificity values of 0.955, 1.000, and 0.875, respectively.

CONCLUSION

The radiomics-based detection model demonstrates excellent automatic identification performance for early sacroiliitis.

New bone formation at the sacroiliac joint in axial spondyloarthritis: characterization of backfill in MRI and CT

OBJECTIVE

MRI findings of the SI joint space in axial SpA (axSpA) include inflammation and fat metaplasia inside an erosion; the latter is also termed 'backfill'. We compared such lesions with CT to better characterize whether they represent new bone formation.

METHODS

We identified patients with axSpA who underwent both CT and MRI of the SI joints in two prospective studies. MRI datasets were jointly screened by three readers for joint space-related findings and grouped into three categories: type A-high short tau inversion recovery (STIR) and low T1 signal; type B-high signal in both sequences; type C-low STIR and high T1 signal. Image fusion was used to identify MRI lesions in CT before we measured Hounsfield units (HU) in each lesion and surrounding cartilage and bone.

RESULTS

Ninety-seven patients with axSpA were identified and we included 48 type A, 88 type B, and 84 type C lesions (maximum 1 lesion per type and joint). The HU values were 73.6 (s.d. 15.0) for cartilage, 188.0 (s.d. 69.9) for spongious bone, 1086.0 (s.d. 100.3) for cortical bone, 341.2 (s.d. 96.7) for type A, 359.3 (s.d. 153.5) for type B and 446.8 (s.d. 123.0) for type C lesions. Lesion HU values were significantly higher than those for cartilage and spongious bone, but lower than those for cortical bone (P < 0.001). Type A and B lesions showed similar HU values (P = 0.93), whereas type C lesions were denser (P < 0.001).

CONCLUSION

All joint space lesions show increased density and might contain calcified matrix, suggesting new bone formation, with a gradual increase in the proportion of calcified matrix towards type C lesions (backfill).

Distribution of Acute and Chronic Lesions in the Sacroiliac Joints of Patients with Axial Spondyloarthritis

Objective

In this study, we aimed to investigate whether there was a pattern of distribution of acute and chronic lesions in the sacroiliac joints (SIJ) of patients with axial spondyloarthritis (axSpA).

Methods

A total of 96 patients diagnosed as axSpA were retrospectively included in this study. The Spondyloarthritis Research Consortium of Canada sacroiliac joint inflammation score (SIS) and structural score (SSS) were used to evaluate the acute and chronic lesions in the SIJs. Scores representing the distribution of bone marrow edema, fatty lesions and erosions were extracted respectively. By dividing the SIJs into sacral or iliac sections, upper or lower sections, anterior and posterior levels, differences of scores representing acute and chronic lesions were analyzed by Kruskal Wallis’ tests.

Results

SIS scores were not significantly different in sacral or iliac sections, in upper or lower sections, on anterior or posterior levels. SSS scores were also not significantly different in different sections, except for higher occurrence rates of erosions in the iliac sections. Post-hoc analysis showed that there was a higher erosion score in the left ilium than left sacrum, as well as in right ilium than left sacrum.

Conclusion

There was no specific distribution pattern of acute or chronic lesions in the SIJs in patients with axSpA. A bigger study sample was needed to confirm the distribution of erosions in sacral or iliac sections.

Australian Consensus Statements for the Assessment and Management of Non-radiographic Axial Spondyloarthritis

Background

The understanding of non-radiographic axial spondyloarthritis (nr-axSpA) has accelerated over the last decade, producing a number of practice-changing developments. Diagnosis is challenging. No diagnostic criteria exist, no single finding is diagnostic, and other causes of back pain may act as confounders.

Aim

To update and expand the 2014 consensus statement on the investigation and management of non‐radiographic axial spondyloarthritis (nr-axSpA).

Methods

We created search questions based on our previous statements and four new topics then searched the MEDLINE and Cochrane databases. We assessed relevant publications by full-text review and rated their level of evidence using the GRADE system. We compiled a GRADE evidence summary then produced and voted on consensus statements.

Results

We identified 5145 relevant publications, full-text reviewed 504, and included 176 in the evidence summary. We developed and voted on 22 consensus statements. All had high agreement. Diagnosis of nr-axSpA should be made by experienced clinicians, considering clinical features of spondyloarthritis, blood tests, and imaging. History and examination should also assess alternative causes of back pain and related conditions including non-specific back pain and fibromyalgia. Initial investigations should include CRP, HLA-B27, and AP pelvic radiography. Further imaging by T1 and STIR MRI of the sacroiliac joints is useful if radiography does not show definite changes. MRI provides moderate-to-high sensitivity and high specificity for nr-axSpA. Acute signs of sacroiliitis on MRI are not specific and have been observed in the absence of spondyloarthritis. Initial management should involve NSAIDs and a regular exercise program, while TNF and IL-17 inhibitors can be used for high disease activity unresponsive to these interventions. Goals of treatment include improving the frequent impairment of social and occupational function that occurs in nr-axSpA.

Conclusions

We provide 22 evidence-based consensus statements to provide practical guidance in the assessment and management of nr-axSpA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00416-7.