The evolution of ultrasound in sarcopenia assessment: Global trends, technological shifts, and clinical frontiers

BackgroundSarcopenia is a progressive skeletal muscle disorder associated with increased disability, morbidity, and mortality. Ultrasound has gained increasing attention as an accessible and repeatable tool for muscle assessment.ObjectiveThis study aimed to map the global research trends and technological evolution in ultrasound-based sarcopenia assessment from 1997 to 2025.MethodsA total of 1574 records were retrieved from the Web of Science Core Collection. Bibliometric analyses were performed using CiteSpace, VOSviewer, and the bibliometrix R package. Sankey diagrams were used to visualize thematic flows between ultrasound assessment dimensions and outcome-related research topics.ResultsPublications showed a prolonged latent phase, steady growth, and rapid acceleration after 2019, peaking in 2025. Keyword and thematic-flow analyses identified a three-stage evolution: an early Morphometry Phase centered on muscle size and atrophy, a Qualitative Transition Phase emphasizing muscle quality and chronic disease contexts, and an Advanced Functional and AI Phase characterized by elastography, AI-assisted analysis, and outcome-related topics. Research contexts expanded across geriatrics, nephrology, critical care, surgical oncology, and rehabilitation-related research.ConclusionUltrasound-based sarcopenia research has shifted toward multidimensional muscle assessment and technology-assisted analysis. Because this study did not appraise individual study quality or clinical effect sizes, the findings should be interpreted as bibliometric patterns and research priorities rather than direct evidence of diagnostic or prognostic effectiveness.