Future use of musculoskeletal ultrasonography and magnetic resonance imaging in rheumatoid arthritis

External Validation of the Machine Learning-Based Thermographic Indices for Rheumatoid Arthritis: A Prospective Longitudinal Study

External validation is crucial in developing reliable machine learning models. This study aimed to validate three novel indices-Thermographic Joint Inflammation Score (ThermoJIS), Thermographic Disease Activity Index (ThermoDAI), and Thermographic Disease Activity Index-C-reactive protein (ThermoDAI-CRP)-based on hand thermography and machine learning to assess joint inflammation and disease activity in rheumatoid arthritis (RA) patients. A 12-week prospective observational study was conducted with 77 RA patients recruited from rheumatology departments of three hospitals. During routine care visits, indices were obtained at baseline and week 12 visits using a pre-trained machine learning model. The performance of these indices was assessed cross-sectionally and longitudinally using correlation coefficients, the area under the receiver operating curve (AUROC), sensitivity, specificity, and positive and negative predictive values. ThermoDAI and ThermoDAI-CRP correlated with CDAI, SDAI, and DAS28-CRP cross-sectionally (ρ = 0.81; ρ = 0.83; ρ = 0.78) and longitudinally (ρ = 0.55; ρ = 0.61; ρ = 0.60), all p < 0.001. ThermoDAI and ThermoDAI-CRP also outperformed Patient Global Assessment (PGA) and PGA + C-reactive protein (CRP) in detecting changes in 28-swollen joint counts (SJC28). ThermoJIS had an AUROC of 0.67 (95% CI, 0.58 to 0.76) for detecting patients with swollen joints and effectively identified patients transitioning from SJC28 > 1 at baseline visit to SJC28 ≤ 1 at week 12 visit. These results support the effectiveness of ThermoJIS in assessing joint inflammation, as well as ThermoDAI and ThermoDAI-CRP in evaluating disease activity in RA patients.

Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory multisystemic disease of unknown etiology and autoimmune nature that predominantly affects peripheral joints in a symmetrical fashion. Although much progress has been made in understanding the pathophysiology of RA, its etiology remains unknown. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 play the important roles in the pathogenesis and maintenance of inflammation in RA. The presence of anti-citrullinated peptide antibodies aids in the diagnosis in patients with undifferentiated polyarthritis and is associated with a more aggressive RA. The natural history of RA causes joint deformity and disability, as well as reduced life expectancy, both due to increased cardiovascular risk, pulmonary involvement, infections, iatrogenesis or tumors. Early diagnosis and the use of targeted drugs to induce early remission have improved the RA prognosis.

E-learning and practical performance in musculoskeletal ultrasound: a multicentre randomized study

OBJECTIVES

To examine the effect of pre-course e-learning on residents' practical performance in musculoskeletal ultrasound (MSUS).

METHODS

This was a multicentre, randomized controlled study following the Consolidated Standards of Reporting Trials (CONSORT) statement. Residents with no or little MSUS experience were randomized to either an e-learning group or a traditional group. One week before a 2-day face-to-face MSUS course, the e-learning group received access to an interactive platform consisting of online lectures, assignments, and practical instruction videos aligned with the content of the course. The traditional group only received standard pre-course information (program, venue, and time). All participants performed a pre- and post-course practical MSUS examination and were assessed by two individual raters, blinded to the group allocation, using the validated Objective Structured Assessment of Ultrasound Skills (OSAUS) tool.

RESULTS

Twenty-eight participants completed the study. There were no statistically significant differences in the pre- or post-course practical MSUS performance between the e-learning group and the traditional group; the mean pre-course OSAUS score (s.d.) in the -learning group was 5.4 (3.7) compared with 5.2 (2.4) in the traditional group (P = 0.8), whereas the post-course OSAUS score in the e-learning group was 11.1 (2.8) compared with 10.9 (2.4) in the traditional group (P = 0.8). There was a significant difference between the mean pre- and post-course scores (5.74 points, P < 0.001). The OSAUS assessment tool demonstrated good inter-rater reliability (intra-class correlation = 0.84).

CONCLUSION

We found no significant impact of pre-course e-learning on novices' acquisition of practical MSUS skills. Hands-on training is of the utmost importance and improves MSUS performance significantly. The OSAUS assessment tool is an applicable tool with high interrater reliability.

TRIAL REGISTRATION

https://clinicaltrials.gov/ NCT04959162.

Difficult to treat rheumatoid arthritis in a comprehensive evaluation program: frequency according to different objective evaluations

Difficult-to-treat Rheumatoid Arthritis (RA-D2T) is a condition in which patients do not achieve the treatment target despite multiple advanced therapies, more others features. Aims: to estimate the frequency of RA-D2T in a cohort comprehensively evaluated (clinical, serology, imaging), and to analyze the associated characteristics. In a second part, the frequency of RA-D2T after 1 year of follow-up, analyzing the predictive variables at baseline and therapeutic behavior. Cross-sectional and prospective study, consecutive RA were included, then those who completed the one-year follow-up were evaluated. RA-D2T frequency was estimated (DAS28-CDAI-SDAI-Ultrasonography (US)-HAQ) at baseline and 1 year. The variables associated and those baseline predictive characteristics of D2T at 1 year, and their independent association by logistic regression were analyzed. The treatment approach was described. Two hundred seventy-six patients completed the evaluation, frequency of RA-D2T (all scores): 27.5%. Anemia, RF high titers and higher HAQ score were independent associated. At year, 125 competed follow-up. RA-D2T (all scores): 33%, D2T-US and D2T-HAQ were 14 and 18.4% (p 0.001). Predictive baseline characteristics D2T (all score): ACPA + (OR: 13.7) and X-ray erosion (OR: 2.9). D2T-US: X-ray erosion (OR: 19.7). Conventional DMARDs, corticosteroids and TNF-blockers were the drugs most used by D2T patients, Jaki were the most used in the switch. We showed different frequencies of RA-D2T according to different objective parameters (scores, images) and their association with patient characteristics. In turn, predictive variables (erosions-ACPA) for RA-D2T at 1 year were analyzed. It was shown that the Jaki were the most used drug in these patients.

Vascular supply of the metacarpophalangeal joint

Objective

To describe in detail the arterial vasculature of metacarpophalangeal joints 2–5 on cadaver specimens and to compare it to ultrasound imaging of healthy subjects.

Methods

Eighteen hands of donated human cadavers were arterially injected and investigated with either corrosion casting or cryosectioning. Each layer of cryosectioned specimens was photographed in high-resolution. Images were then segmented for arterial vessels of the metacarpophalangeal (MCP) joints 2–5. The arterial pattern of the joints was reconstructed from the segmented images and from the corrosion cast specimens. Both hands of ten adult healthy volunteers were scanned focusing on the vasculature of the same joints with high-end ultrasound imaging, including color Doppler. Measurements were made on both cryosectioned arteries and Doppler images.

Results

The arterial supply of MCP joints 2–5 divides into a metacarpal and a phalangeal territory, respectively. The metacarpal half receives arteries from the palmar metacarpal arteries or proper palmar digital arteries, while the phalangeal half is supplied by both proper and common palmar digital arteries. Comparing anatomical and ultrasonographic results, we determined the exact anatomic location of normal vessels using Doppler images acquired of healthy joints. All, except three branches, were found with less than 50% frequency using ultrasound. Doppler signals were identified significantly more frequently in MCP joints 2–3 than on 4–5 (p < 0.0001). Similarly, Doppler signals differed in the number of detectable small, intraarticular vessels (p < 0.009), but not that of the large extraarticular ones (p < 0.1373). When comparing measurements acquired by ultrasound and on cadaver vessels, measurements using the former technique were found to be larger in all joints (p < 0.0001).

Conclusion

Using morphological and ultrasonographic techniques, our study provides a high-resolution anatomical maps and an essential reference data set on the entire arterial vasculature of healthy human MCP 2–5 joints. We found that Doppler signal could be detected in less than 50% of the vessels of healthy volunteers except three locations. Intraarticular branches were detected with ultrasound imaging significantly more frequently on healthy MCP 2–3 joints, which should be taken into account when inflammatory and normal Doppler signals are evaluated. Our study also provides reference data for future, higher-resolution imaging techniques.

Assessment of inflammation in patients with rheumatoid arthritis using thermography and machine learning: a fast and automated technique

Objectives

Sensitive detection of joint inflammation in rheumatoid arthritis (RA) is crucial to the success of the treat-to-target strategy. In this study, we characterise a novel machine learning-based computational method to automatically assess joint inflammation in RA using thermography of the hands, a fast and non-invasive imaging technique.

Methods

We recruited 595 patients with arthritis and osteoarthritis, as well as healthy subjects at two hospitals over 4 years. Machine learning was used to assess joint inflammation from the thermal images of the hands using ultrasound as the reference standard, obtaining a Thermographic Joint Inflammation Score (ThermoJIS). The machine learning model was trained and tuned using data from 449 participants with different types of arthritis, osteoarthritis or without rheumatic disease (development set). The performance of the method was evaluated based on 146 patients with RA (validation set) using Spearman’s rank correlation coefficient, area under the receiver-operating curve (AUROC), average precision, sensitivity, specificity, positive and negative predictive value and F1-score.

Results

ThermoJIS correlated moderately with ultrasound scores (grey-scale synovial hypertrophy=0.49, p<0.001; and power Doppler=0.51, p<0.001). The AUROC for ThermoJIS for detecting active synovitis was 0.78 (95% CI, 0.71 to 0.86; p<0.001). In patients with RA in clinical remission, ThermoJIS values were significantly higher when active synovitis was detected by ultrasound.

Conclusions

ThermoJIS was able to detect joint inflammation in patients with RA, even in those in clinical remission. These results open an opportunity to develop new tools for routine detection of joint inflammation.

Musculoskeletal ultrasound for treating rheumatoid arthritis to target-a systematic literature review

OBJECTIVE

We aimed to systematically review the literature to retrieve evidence on the diagnostic and prognostic value of musculoskeletal ultrasound for a treat to target (T2T) approach in RA.

METHODS

Eight research questions were developed addressing the role of ultrasound (including different ultrasound scores and elementary lesions) for diagnosis, monitoring and prognosis of RA. PubMed and EMBASE were searched (2005-2020). Articles on RA and reporting data on musculoskeletal ultrasound were included and extracted according to the underlying questions, and risk of bias assessed according to the study design.

RESULTS

Out of 4632 records, 60 articles were included. Due to clinical heterogeneity, meta-analysis was not possible. Ultrasound better predicted disease relapses with respect to clinical examination in patients in remission, while both methods performed similarly in predicting response to therapy, achievement of remission and radiographic progression. Ultrasound was superior to clinical examination in diagnosing joint involvement using another imaging modality, such as magnetic resonance imaging, as reference. Limited ultrasound scores performed like more extensive evaluations for the detection of joint inflammation and for outcome prediction. Higher ultrasound scores of synovitis were linked to poor outcomes at all disease stages, but a specific cut-off distinguishing between low- and high-risk groups did not emerge.

CONCLUSIONS

These data confirm the pivotal role of ultrasound when evaluating synovial inflammation and when identifying RA patients at higher risk of relapse. Further research is needed to better define the role of ultrasound in a T2T management strategy in moderately-to-highly active RA.

Training and assessment of musculoskeletal ultrasound and injection skills-a systematic review

OBJECTIVES

To examine how residents are trained and assessed in musculoskeletal ultrasound (MSUS), MSUS-guided and landmark-guided joint aspiration and injection. Additionally, to present the available assessment tools and examine their supporting validity evidence.

METHODS

A systematic search of PubMed, Cochrane Library, and Embase was conducted in accordance with the PRISMA guidelines and studies published from January 1, 2000 to May 31, 2021 were included. Two independent reviewers performed the search and data extraction. The studies were evaluated using the Medical Education Research Quality Instrument (MERSQI).

RESULTS

9,884 articles were screened, and 43 were included; 3 were randomized studies, 21 pre- and post-test studies, 16 descriptive studies, and 3 studies developing assessment tools. The studies used various theoretical training modalities e.g. lectures, anatomical quizzes and e-learning. The practical training models varied from mannequins and cadavers to healthy volunteers and patients. The majority of studies used subjective "comfort level" as assessment, others used practical examination and/or theoretical examination. All training programs increased trainees' self-confidence, theoretical knowledge, and/or practical performance, however few used validated assessment tools to measure the effect. Only one study met the MERSQI high methodical quality cut-off score of 14.

CONCLUSION

The included studies were heterogeneous, and most were of poor methodological quality and not based on contemporary educational theories. This review highlights the need for educational studies using validated theoretical and practical assessment tools to ensure optimal MSUS training and assessment in rheumatology.

A broad look into the future of rheumatoid arthritis

Despite all improvements in rheumatoid arthritis, we are still not able to prevent or cure the disease. Diagnostic delays due to lack of access to a specialist and costly therapies are still a major obstacle for many patients. Even in first-world countries, the treat-to-target principle and the goal of disease remission are often missed. Thus, rheumatoid arthritis (RA) is still the reason for disability and reduced quality of life for many patients. So, is it time to move the goalpost even further? Where are we heading next? And will we finally be able to cure the disease? These questions are addressed in our review article.

Current Practice of Imaging-Guided Interventional Procedures in Rheumatic and Musculoskeletal Diseases: Results of a Multinational Multidisciplinary Survey

Objectives: To investigate opinion and routine practice of specialists from different disciplines on imaging techniques for interventional procedures related to rheumatic and musculoskeletal diseases (RMDs). Methods: An English-language questionnaire was developed by an international working group and distributed to health care providers of various disciplines involved in the care of people with RMDs via an online survey tool (SoSci Survey®) from December 2019 to May 2020. Results: A total of 1,105 respondents from 56 countries completed the survey, over 60% of participants were rheumatologists. The majority of respondents (88%) performed interventional procedures in RMDs patients and 90% of them used imaging guidance. Ultrasonography was the most frequently used technique, particularly among rheumatologists. X-ray and computed tomography were mainly used by radiologists. A discrepancy emerged between the importance assigned to certain items such as the availability of a second operator and their actual implementation in clinical practice. Local barriers, lack of resources and facilities were mentioned as the most relevant obstacles in this regard. Lack of training on imaging and/or imaging guided procedures did not emerge as a barrier to perform such interventions; in fact, 19% of respondents performing the procedures indicated not to have received adequate training in this field. Conclusions: This is the first multinational multidisciplinary survey exploring in detail the opinions and practice on imaging guidance for interventional procedures in RMDs. A harmonization of protocols based on international guidelines, along with adequate training programmes and interventions on barriers at national/local levels are the main unmet needs requiring attention.

First assessment of thermoacoustic tomography for in vivo detection of rheumatoid arthritis in the finger joints detection of rheumatoid arthritis in the finger joints

BACKGROUND

The diagnosis of rheumatoid arthritis (RA) is complicated because of the complexity of symptoms and joint structures. Current clinical imaging techniques for the diagnosis of RA have strengths and weaknesses. Emerging imaging techniques need to be developed for the diagnosis or auxiliary diagnosis of RA.

PURPOSE

This study aimed to demonstrate the potential of thermoacoustic tomography (TAT) for in vivo detection of RA in the finger joints.

METHODS

Finger joints were imaged by a TAT system using three different microwave illumination methods including pyramidal horn antenna, and parallel in-phase and anti-phase microwave illuminations. Both diseased and healthy joints were imaged and compared when the three microwave illumination methods were used. Magnetic resonance imaging (MRI) of all the joints was performed to validate the TAT findings. In addition, two diseased joints were imaged at two time points by the pyramidal horn antenna-based TAT to track/monitor the progression of RA during a time period of 16 months. Three-dimensional (3-D) TAT images of the joints were also obtained.

RESULTS

The TAT images of the diseased joints displayed abnormalities in bone and soft tissues compared to the healthy ones. The TAT images by pyramidal horn antenna and in-phase microwave illumination showed high similarity in image appearance, while the anti-phase-based TAT images provided different information about the disease. We found that the TAT findings matched well with the MRI images. The 3-D TAT images effectively displayed the stereoscopic effect of joint lesions. Finally, it was evident that TAT could detect the development of the lesions in 16 months.

CONCLUSION

TAT can noninvasively visualize bone lesions and soft tissue abnormalities in the joints with RA. This first in vivo assessment of TAT provides a foundation for its clinical application to the diagnosis and monitoring of RA in the finger joints.

Reappraisal of bone scintigraphy as a new tool for the evaluation of disease activity in patients with rheumatoid arthritis

We aimed to compare the reliability of bone scintigraphy (BS) and fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)-derived parameters in the detection of active arthritis in 28-joint areas and evaluate the reliability of joint counts between BS and clinical assessment in patients with rheumatoid arthritis (RA). We enrolled 106 patients (67 in the development group and 39 in the validation groups) with active RA who underwent BS, ¹⁸F-FDG PET/computed tomography (CT), and clinical evaluation of disease activity. We compared the results of BS-derived joint assessment with those of PET-derived and clinical joint assessments. Subsequently we developed a disease activity score (DAS) using BS-positive joints and validated it in an independent group. The number of BS-positive joints in 28-joint areas significantly correlated with the swollen /tender joint counts (SJC/TJC) and PET-derived joint counts. A BS uptake score of 2 (strong positive) was significantly more sensitive compared with a BS uptake score of 1 (weak positive) in detecting a PET-positive joint among the 28-joints. After conducting multivariate analyses including erythrocyte sediment rate (ESR) and patient global assessment (PGA) in addition to BS-derived parameters, BS/DAS was obtained as follows: 0.056 × number of BS-positive joints in 28 joints + 0.012 × ESR + 0.030 × PGA. A significant correlation between BS/DAS and DAS28-ESR was confirmed in the validation group. Strong positive uptake of BS is sensitive and reproducible for the detection of active joints, and can complement the clinical assessment of disease activity in RA.

The Role of Imaging in Predicting the Development of Rheumatoid Arthritis

Rheumatoid arthritis (RA) remains a chronic debilitating disease with a significant negative societal impact, despite the expanding landscape of treatment options. This condition is often preceded by a phase of systemic autoimmunity with circulating autoantibodies, elevated pro-inflammatory cytokines, or subtle structural changes. The capability of identifying individuals in the preclinical phase of RA disease makes a "preventive window of opportunity" possible. Much recent work has focused on the role of imaging modalities including ultrasound (US), magnetic resonance imaging (MRI), and high-resolution peripheral quantitative computer tomography (HR-pQCT) in identifying at-risk individuals with or without early joint symptoms for the development of inflammatory arthritis. This article will review the evidence and discuss the challenges as well as opportunities of proactive risk assessment by imaging in RA.