Ultrasonography in Rheumatology: 5 Years of Transformation and the Road Ahead

Over the past 5 years, musculoskeletal ultrasonography (MSUS) has undergone significant development in rheumatology. Formerly regarded mainly as a supplementary tool to physical examination—useful for procedures and clarifying early inflammatory arthritis—MSUS has now become a crucial imaging modality, increasingly supported by evidence, standardized methods, and greater integration into patient care pathways. Technological advancements, international consensus initiatives, and expanding clinical applications have collectively repositioned MSUS as a vital component of precise, patient-centered rheumatology. During this period, the APLAR Imaging SIG has actively promoted structured training in MSUS and expanded its use in diagnosing various rheumatic diseases. This editorial highlights the major developments of the last 5 years, their implications for rheumatology practices across diverse global settings, the priorities necessary for further progress, and the role of organizations such as SIGs in fostering relevant training. A significant milestone in the development of MSUS has been the ongoing standardization of definitions and scoring methods. Collaborative efforts, especially through the EULAR–OMERACT partnership, have refined and validated definitions and scoring techniques for synovitis, tenosynovitis, and other important pathologies. These initiatives have improved the consistency, reliability, and interpretability of MSUS findings across centers, enabling meaningful comparison of data between studies and supporting its use in clinical trials [1-4]. This improved standardization has increased recognition of MSUS as a reliable outcome measure in research. It has allowed multicenter and international studies to include MSUS endpoints more confidently—a vital step towards integrating imaging into treat-to-target strategies. For future development, continued global cooperation is essential to ensure these frameworks remain relevant and adaptable across different resource settings and across various machine manufacturers. A key development with significant clinical implications is the expanding role of power Doppler (PD). Evidence now consistently shows that the persistence of PD signals—even in clinically inactive joints—correlates to higher risks of flare-ups, structural progression, and poorer clinical outcomes [5-7]. This understanding encourages a paradigm shift in which MSUS is not just a diagnostic tool but also a prognostic one, assisting in risk assessment and treatment planning. For rheumatologists, this emerging evidence raises critical questions: How should PD activity guide treatment decisions, such as tapering or continuing biologic therapy? Can “ultrasound remission” become a meaningful goal alongside clinical remission? While the potential benefits are promising, imaging-guided treatment strategies require validation through pragmatic trials to confirm their practicality and long-term value across different healthcare systems. Existing evidence, including data from earlier ARCTIC and TaSER trials or recent studies, so far does not support the necessity of ultrasound-driven treat-to-target approaches in the management of rheumatoid arthritis [8-11]. To address longstanding concerns surrounding operator dependency, several quantitative and functional imaging techniques are gaining popularity. Shear-wave elastography (SWE), which measures tissue stiffness, has shown promise in distinguishing active inflammatory synovitis from chronic, fibrotic changes and in monitoring treatment response [12, 13]. Likewise, efforts are underway to quantify synovial vascularity through automated Doppler signal analysis, aiming to improve reproducibility and minimize subjectivity [14, 15]. These techniques could enhance reliability across centers and equipment vendors, which is vital for broader adoption in research and clinical practice. However, their use in routine care is still constrained by differences between ultrasound platforms, a lack of standardization, and the need for more comprehensive longitudinal studies linking quantitative metrics to patient outcomes. Building a unified, cross-vendor framework remains a top priority. In many areas—especially in low- and middle-income countries and regions like many APLAR areas—where access to expert MSUS training is limited, AI-supported devices with fast internet may eventually democratize high-quality ultrasound assessment. With the advancement of technology, automated ultrasound systems performed by robots that incorporate AI for scoring disease activity have been studied [18, 19]. Although they were reported to be safe and well-received by patients, these systems are currently only used for scanning the hands. Most AI models and robotic systems are still in the proof-of-concept stage. Greater external validation, diverse population training datasets, ethical safeguards, and regulatory approvals are essential before widespread clinical deployment. Collaboration among clinicians, technologists, and regulatory authorities will be crucial to ensuring safe and fair implementation. Despite notable progress, equitable access to MSUS remains challenging. Training opportunities vary significantly across regions, and disparities in equipment availability persist. The growth of point-of-care ultrasound (POCUS) has generated enthusiasm, particularly for swift clinical decision-making; however, structured competency-based training must accompany its expansion to ensure safe and effective use. APLAR Imaging SIG has started an initiative in such training through a series of webinars on point-of-care rheumatology ultrasound (POCRUS), which has been widely appreciated [22]. Innovations such as simulation-based learning, tele-mentoring, standardized curricula, and AI-supported training tools hold promise for expanding capacity. For journals like the International Journal of Rheumatic Diseases, there is a vital role in promoting research and implementation strategies from low-resource settings to ensure global relevance and inclusivity. Several obstacles still hinder the widespread adoption of MSUS. These include well-recognized issues such as operator dependence and workflow constraints in busy clinical settings. More robust evidence on its cost-effectiveness and outcome-driven data is needed to persuade healthcare administrators to make MSUS a standard rheumatology service. Furthermore, the variability in machine performance and the absence of cross-vendor standardization also need to be addressed. Limited access to training programs in certain regions, especially within APLAR countries, remains a challenge. Overcoming these issues will require international collaboration, strategic investment, and ongoing research into harmonization and technology-driven training. The next stage of MSUS advancement may need to focus on specific areas. It will be important to further define the roles of MSUS applications in various clinical scenarios to guide our daily management decisions. Disseminating such crucial updated knowledge among rheumatologists through different channels is necessary. Widespread implementation of standardized core training will be essential. Training for the use of MSUS in specialized areas, including vascular, salivary glands, lung, and pediatric applications, should be given attention. Advancing quantitative ultrasound with the aid of AI will certainly enhance performance consistency and facilitate integration into routine practice. Furthermore, promoting research from diverse global regions will ensure the applicability of existing clinical standards across different populations. If these goals are achieved, MSUS will become a universally accessible, consistent, and effective tool that meaningfully enhances diagnostic accuracy, treatment outcomes, and patient-centered care. The last 5 years have seen MSUS evolve from a supportive to a strategic role within rheumatology. Advances in standardization, prognostic Doppler assessment, quantitative techniques, AI augmentation, and broader clinical application showcase a modality quickly gaining both maturity and momentum. Fully realizing the potential of MSUS will depend on validating its impact on long-term outcomes, ensuring global access to structured and high-quality training, and embracing technological innovations that improve consistency and equity. With thoughtful implementation, MSUS can become a cornerstone of modern, precision-driven rheumatology—delivering better outcomes for patients worldwide. K.O.K. and G.K.-W.L. contributed equally to the construction, idea generation, writing, and proofreading. This editorial was jointly written by us, inspired by our work over the years as convener and coconvener of the APLAR Imaging SIG, especially through supporting the APLAR Pre-Congress MSUS Workshops over the years, regional MSUS Workshops in member countries, and the APLAR 2025 Pre-Congress Workshop on “Giant Cell Arteritis, Polymyalgia Rheumatica, and Takayasu Arteritis: A Unified Spectrum of Large Vessel Vasculitis.” We sincerely thank all members of the APLAR Imaging SIG for their ongoing support. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.