A bibliometric analysis of the association between ultrasound and sarcopenia: Trends, networks, and future directions

Abstract

Objective:

With the escalating global prevalence of sarcopenia, the demand for effective diagnostic tools is critical. While ultrasound shows promise as a noninvasive assessment method, a comprehensive analysis of its research landscape is limited. This study employs a bibliometric approach to objectively map the field, identify key contributors, and explore future research frontiers.

Methods:

We systematically searched the Web of Science Core Collection for literature on ultrasound and sarcopenia published over the past 2 decades. Bibliometric software, including VOSviewer, CiteSpace, and R, was used to analyze publication trends, collaboration networks, and core research themes. Visualizations were generated to map research output across countries, institutions, journals, authors, and keywords.

Results:

A total of 907 publications were included. Japan emerged as the most prolific country, and Hacettepe University as the leading research institution. Among individual researchers, Takashi Abe had the highest publication count. Regarding journals, Nutrients published the most literatures, while the Journal of Cachexia, Sarcopenia and Muscle led in publication volume, impact factor, h-index, and g-index. The most frequent keyword was “Sarcopenia,” with “echo intensity” and “b-mode ultrasound” exhibiting the strongest burst intensity. Recent research hotspots have centered on topics such as “artificial intelligence,” “disease-related malnutrition,” “shear wave elastography,” “nonalcoholic fatty liver disease,” “phase angle,” and more.

Conclusions:

This bibliometric study offers an objective overview of the research landscape concerning ultrasound and sarcopenia, revealing a rapidly expanding domain. By mapping the current field, this work aims to inform future research directions and address critical knowledge gaps.

1. Introduction

With the accelerating global aging process, age-related skeletal muscle decline and functional impairment: known as sarcopenia: has become an important clinical concern. Characterized by progressive loss of muscle mass, strength, and physical function, sarcopenia is associated with increased risks of falls, cancers, cardiovascular events, and premature death.^[1] The global prevalence of sarcopenia ranges from approximately 8 to 36% in individuals under 60 years old, while it falls from 10 to 27% among those aged 60 years and older, with a rising trend.^[2] In Chinese hospitalized older adults, prevalence reaches 29.7% in males and 23% in females,^[3] while rates among patients with gastrointestinal cancer range from 12 to 78%.^[4] Moreover, sarcopenia is associated with poorer clinical outcomes following major cancer surgery and during hospitalization for acute and chronic diseases.^[4–11] Consequently, sarcopenia significantly impairs quality of life and imposes a substantial burden on public health and healthcare systems.

In clinical practice, sarcopenia is often overlooked and undertreated. Its diagnosis relies on a comprehensive evaluation of muscle mass, muscle strength, and physical function, with muscle mass assessment being particularly crucial.^[12] Current imaging methods like computed tomography (CT) are largely confined to research settings due to high cost, long examination time, and radiation risk, making them unsuitable for routine clinical use.^[13] Dual-energy X-ray absorptiometry (DXA) is widely used for body composition assessment due to its accuracy and repeatability. However, it cannot assess intramuscular fat infiltration or provide qualitative information about muscle tissue.^[12,14] DXA measurements are also susceptible to body thickness, hydration status, and fluid retention, which may compromise accuracy.^[12,14] In contrast, bioelectrical impedance analysis (BIA) is noninvasive, radiation-free, and easy to operate, making it recommended for sarcopenia diagnosis. However, it estimates muscle mass indirectly via predictive equations rather than direct measurement. Its accuracy is affected by hydration status and other factors, rendering it unsuitable for patients with edema, amputation, or implanted electronic devices.^[12,15]

Ultrasound has emerged as a promising tool for assessing muscle mass and structure in sarcopenia, offering advantages such as no radiation, dynamic soft tissue assessment, portability, and accessibility.^[16–18] The European Geriatric Medicine Society has proposed a consensus protocol for ultrasound muscle assessment, advocating its expanded use in sarcopenia evaluation.^[19] Similarly, the European Working Group on Sarcopenia in Older People (EWGSOP) has recommended ultrasound as a reliable method for assessing muscle quantity and quality.^[12] A review by Shi Wei Ang et al suggested that ultrasound may have higher diagnostic value for sarcopenia in Asian populations compared to BIA and DXA.^[20] Although standardized application of ultrasound still faces challenges, its clinical value and potential are widely recognized.

As ultrasound technology has become more widely applied in sarcopenia research, the number of relevant studies has grown rapidly. However, a systematic bibliometric analysis of the research dynamics and knowledge structure in this field is still lacking. Traditional review articles often fail to provide a comprehensive and objective overview of the field developmental trajectory, collaboration networks, or evolving research hotspots. Bibliometrics, a quantitative method based on mathematical statistics, can systematically reveal developmental trends, research hotspots, core authors, and collaboration networks.^[21] Therefore, this study employs a bibliometric approach to comprehensively analyze the literature on ultrasound in sarcopenia research. It covers spatio-temporal distribution, collaboration network construction, and keyword co-occurrence and evolution analysis. The goal is to identify key research directions and emerging hotspots, thereby providing a scientific basis and new perspectives for future research.

2. Methods

2.1. Data source and search strategy

This bibliometric analysis was conducted in accordance with the Preliminary guideline for reporting bibliometric reviews of the biomedical literature (BIBLIO).^[22] The data used in this study were retrieved from the Web of Science Core Collection (WoSCC). This database is widely recognized for its extensive coverage of high-impact journals across various disciplines, its robust and reliable citation network, and its strong interdisciplinary nature, making it a preferred data source for bibliometric research.^[23,24] The search was limited to the “Science Citation Index Expanded” and “Social Sciences Citation Index” sub-databases within WoSCC. The search strategy was as follows: TS = (sarcopen* OR myopeni* OR dynaponi*) AND TS = (ultrasonic* OR ultrasonography OR ultrasound OR sonography OR ultraso*imaging OR echography OR elastography OR sonoelastography). An initial search yielded 1029 publications. The search time frame was then restricted from January 1, 2005, to August 27, 2025, and the document types were limited to research articles and reviews, with the language set to English. After excluding non-research documents such as meeting abstracts, letters, and editorials, and removing duplicate and retracted records, a final total of 907 publications were included for subsequent analysis. The entire search process was completed on August 28, 2025. A detailed search flow is shown in Figure 1.

Figure 1.

Flow chart of literature screening.

2.2. Data analysis

This study employed bibliometric methods, utilizing a combination of Excel, CiteSpace (6.3.R1), VOSviewer (1.6.20), and the R language (4.4.3) with the bibliometrix package for the analysis of the included literature. First, Excel was used to count the number of annual and cumulative publications and generate corresponding charts to reveal the temporal evolution of publication volume in this field. Building on this, CiteSpace, VOSviewer, and bibliometrix were further used to conduct in-depth analyses on dimensions such as country, author, institution, and journal distribution, as well as keyword co-occurrence. Scientific knowledge maps were generated to visualize these findings, providing a systematic and multi-dimensional representation of the research structure and dynamic hotspots in this field. In the collaboration network analysis, Betweenness centrality was used to quantify the importance of nodes in the collaboration network. A score > 0.1 indicates that a country/node acts as a critical hub, facilitating connections and knowledge flow between different research clusters.

2.3. Research ethics

The data employed in this study do not encompass any patient clinical information; consequently, ethical approval is deemed unnecessary.

3. Results

3.1. Annual scientific production

Figure 2 illustrates the trend of annual publications in the field of ultrasound and sarcopenia. Since 2005, the number of relevant papers has shown a significant growth trajectory. From 2005 to 2017, the number of publications was in a slow upward phase, with fewer than 30 literatures published annually. However, starting in 2018, the number of yearly publications began to increase markedly. Between 2018 and 2024, the number of literatures climbed year by year, first exceeding 100 in 2021 and reaching 151 in 2024, a threefold increase compared to 2018. This notable growth reflects a strong and increasing interest among researchers in the application of ultrasound in sarcopenia research. From January 1 to August 27, 2025, 106 papers have already been published, which is nearly on par with the average annual output from 2021 to 2023. Based on the current growth trend, the total number of papers for 2025 is expected to surpass that of 2024.

Figure 2.

The trend in annual scholarly article publications.

3.2. Analysis of countries

Figure S1 displays the distribution of publications by country in the field of ultrasound and sarcopenia. According to Table 1, the top 3 countries by cumulative publication volume are Japan, the United States (U.S.), and China, with each having published over 100 papers in the last 2 decades. These are followed by Spain (95 papers), Italy (88 papers), England (72 papers), South Korea (62 papers), Turkey (53 papers), Canada (47 papers), and Brazil (42 papers). Centrality is used to assess a country influence and importance within the international collaboration network in this field. Countries with a centrality score exceeding 0.1 include Japan, the U.S., Spain, Italy, England, and Canada, indicating that these nations are more prominent in international collaborations and demonstrate stronger connectivity and academic influence.

Table 1.

Top 10 countries for publications.

Rank	Country/Region	Publications	Centrality
1	Japan	169	0.11
2	USA	148	0.29
3	China	130	0.04
4	Spain	95	0.21
5	Italy	88	0.26
6	England	72	0.24
7	South Korea	62	0.02
8	Turkey	53	0.03
9	Canada	47	0.13
10	Brazil	42	0.05

Centrality (betweenness centrality) measures a country influence in the international collaboration network; scores > 0.1 indicate critical hubs.

3.3. Contribution of authors

A total of 5124 authors contributed to papers on ultrasound-related research in the field of sarcopenia. Figure S2 shows the collaboration network of authors with 5 or more publications. According to Table 2, there are 4 authors with more than 20 publications in this field: Takashi Abe (29 papers), Murat Kara (22 papers), Jeremy P. Loenneke (21 papers), and Levent Özçakar (21 papers). The h-index is used to measure the number of a scientist core highly-cited papers, while the g-index reflects the overall impact of those highly-cited papers. Notably, Takashi Abe not only ranks first in terms of publication volume and average citations per paper but also holds the top position for both h-index and g-index, indicating his significant academic influence in this field.

Table 2.

Author impact analysis.

Rank	Author	Country	Documents	Avg. citations	h-index	g-index
1	Takashi Abe	Japan	29	41	18	29
2	Murat Kara	Turkey	22	25	11	22
3	Jeremy P. Loenneke	U.S.	21	34	16	21
4	Levent Özçakar	Turkey	21	30	12	21
5	Robert S. Thiebaud	U.S.	19	35	16	19
6	Mustafa Cankurtaran	Turkey	18	10	7	13
7	Burcu Balam Dogu	Turkey	15	6	5	9
8	Naoki Akazawa	Japan	14	21	10	14
9	Hideki Moriyama	Japan	14	21	10	14
10	Kimiyuki Tamura	Japan	14	21	10	14
11	Bayram Kaymak	Turkey	14	33	9	14

Avg. citations = total citations divided by number of documents; h-index measures the number of core highly-cited papers; g-index reflects the overall impact of highly-cited papers.

3.4. Analysis of journals

A total of 330 journals has published papers on research related to ultrasound and sarcopenia. Figure S3 illustrates the distribution of journals with 3 or more publications. Based on the data in Table 3, the top 3 journals by publication volume are Nutrients (44 papers), Journal of Cachexia Sarcopenia and Muscle (27 papers), and Scientific Reports (19 papers). Among these, the Journal of Cachexia Sarcopenia and Muscle have the highest impact factor (IF) among the top 11 journals by publication volume, reaching 9.1. Furthermore, Nutrients and the Journal of Cachexia Sarcopenia and Muscle are both leading in terms of publication volume, h-index and g-index. Additionally, journals such as Archives of Gerontology and Geriatrics, Aging Clinical and Experimental Research, Clinical Nutrition, Clinical Interventions in Aging, and Experimental Gerontology also show high h-index and g-index, reflecting their significant influence and academic contribution to this research area.

Table 3.

Top 11 journals for publications.

Rank	Journal	Documents	IF*	h-index	g-index
1	Nutrients	44	5.0	14	21
2	Journal of cachexia sarcopenia and muscle	27	9.1	14	27
3	Scientific reports	19	3.9	8	12
4	BMC geriatrics	18	3.8	7	11
5	Archives of gerontology and geriatrics	17	3.8	13	17
6	Journal of clinical medicine	17	2.9	10	16
7	Aging clinical and experimental research	16	3.4	11	16
8	European geriatric medicine	16	3.6	6	16
9	Clinical nutrition	15	7.4	13	15
10	Clinical interventions in aging	15	3.7	10	15
11	Experimental gerontology	15	4.3	10	15

^*IF = impact factor; IF in category according to Journal Citation Reports (2024).

3.5. Contribution of institutions

A total of 1564 institutions have published relevant papers in the field of ultrasound and sarcopenia research. Figure S4 shows the distribution of institutions with 5 or more publications. Among them, Hacettepe University leads significantly in publication volume with 46 papers, followed by the University of Mississippi and Yonsei University, with 19 and 18 papers, respectively (Table 4). However, in terms of average citations per paper, among the top 10 institutions by publication volume, the National Institute of Fitness and Sports in Kanoya ranks first with an average of 29 citations per paper.

Table 4.

Top 10 institutions for publications.

Rank	Institution	Country	Documents	Citations	Avg. citations
1	Hacettepe University	Turkey	46	804	13
2	University of Mississippi	U.S.	19	586	23
3	Yonsei University	South Korea	18	232	2
4	Kobe University	Japan	17	328	22
5	University of Birmingham	England	17	345	13
6	University of Nottingham	England	17	568	21
7	Manchester Metropolitan University	England	16	747	11
8	National Institute of Fitness and Sports in Kanoya	Japan	16	600	29
9	Instituto de Salud Carlos III	Spain	15	140	15
10	University of Malaga	Spain	15	151	11

Avg. citations = total citations divided by number of documents.

3.6. Analysis of keywords

Keyword co-occurrence analysis is a crucial bibliometric method for identifying research hotspots and predicting future trends. By statistically analyzing the frequency of keywords in this field (Figure S5), we have listed the top 20 high-frequency keywords (Table 5). These keywords primarily fall into 2 major themes: first, target populations and related diseases, such as sarcopenia, frailty, malnutrition, sarcopenic obesity, nonalcoholic fatty liver disease, aging, and older adults; and second, ultrasound techniques and assessment methods, such as ultrasound, ultrasonography, rectus femoris, muscle mass, muscle thickness, muscle strength, muscle quality, echo intensity, and body composition.

Table 5.

Top 20 most frequent keywords.

Rank	Keyword	Frequency
1	sarcopenia	438
2	ultrasound	191
3	ultrasonography	103
4	muscle mass	71
5	aging	65
6	frailty	60
7	body composition	58
8	muscle	55
9	muscle thickness	55
10	muscle strength	46
11	malnutrition	40
12	muscle quality	40
13	skeletal muscle	40
14	older adults	39
15	skeletal muscle mass	34
16	echo intensity	32
17	nonalcoholic fatty liver disease	30
18	obesity	27
19	rectus femoris	25
20	sarcopenic obesity	23

Furthermore, we extracted the top 25 keywords with the highest burst strength and significant duration through burst analysis (Fig. 3). Among these, the keywords with the strongest bursts were “echo intensity” and “b-mode ultrasound.” Keywords that are currently still in a burst state include: older adults, liver fibrosis, chronic kidney disease, shear wave elastography (SWE), disease-related malnutrition, and handgrip strength.

Figure 3.

Top 25 keywords with the strongest citation burst.

To gain a deeper understanding of recent research hotspots, we visualized the high-frequency keywords that appeared each year (Fig. 4). The results show that recent research hotspots in this field primarily exhibit the following trends: first, the continuous expansion of ultrasound technology applications, with more attention given to topics such as point-of-care ultrasound, muscle ultrasound, artificial intelligence (AI), and shear wave elastography; second, the emergence of new clinical focal points, such as nonalcoholic fatty liver disease, sarcopenic obesity, heart failure, and head and neck cancer; and third, related assessment methods, including morphofunctional assessment, bioelectrical impedance analysis, phase angle (PhA), and activities of daily living.

Figure 4.

Keywords timeline diagram of ultrasound-based sarcopenia research.

4. Discussion

4.1. General bibliometric discussion

In the past 2 decades, the number of publications on ultrasound in sarcopenia research has shown a continuous upward trend, with a notable acceleration after 2018. This trend may stem from 2 reasons: on 1 hand, sarcopenia is receiving increasing attention from researchers as a major component of geriatric syndromes.^[25] On the other hand, in 2018, the European Geriatric Medicine Society presented a consensus on the standardized use of ultrasound for muscle assessment, while the EWGSOP also recommended the use of ultrasound for sarcopenia assessment in its updated definition and diagnostic consensus.^[12,19] The publication of these consensuses has significantly propelled the application and development of ultrasound technology in this field. Notably, the annual publication volume has exceeded 400 papers in the last 4 years, indicating that the application of ultrasound in sarcopenia research is in a stage of rapid development.

Globally, Japan, the U.S., and China are the main contributing countries to research on ultrasound and sarcopenia. Interestingly, the results show that publication volume does not always equate to collaborative influence. For instance, while Japan leads in total output, the United States and Spain exhibit higher betweenness centrality scores (>0.1). This indicates that these nations serve as “knowledge bridges” or hubs in the global network. High centrality suggests that these countries are more likely to participate in cross-continental collaborations and international consensus building, whereas countries with high volume but lower centrality might focus more on large-scale domestic or regional population studies. An analysis of the top ten countries by publication volume reveals that Asian countries are the most numerous, including Japan, China, South Korea, and Turkey; followed by European countries, including Spain, Italy, and England; and American countries, including the U.S., Canada, and Brazil. This distribution suggests a multipolar development pattern in this field globally. The leading countries in publication volume are mainly concentrated in Asia, Europe, and America, a pattern that may be related to the regional nature of sarcopenia diagnostic consensuses. In 2019, the EWGSOP published a definition and diagnostic consensus based on European populations.^[12] Subsequently, the Asian Working Group for Sarcopenia (AWGS) released a corresponding consensus to accommodate the distinct characteristics of the Asian population.^[26] These 2 major consensuses have jointly driven the rapid development of sarcopenia research in Asian, European, and American countries. Although Japan leads in publication volume, the U.S., Spain, Italy, and England demonstrate stronger influence and connectivity in the global collaboration network. In contrast, Asian countries have room for further improvement in their influence in global collaborations. At the institutional level, Hacettepe University in Turkey has the highest publication volume, serving as a major research force in the country and demonstrating its leading position in this field. The University of Mississippi in the U.S. not only excels in publication volume but also has a high average citation count, reflecting its significant research activity and academic influence. It is particularly noteworthy that while the National Institute of Fitness and Sports in Kanoya in Japan has a relatively small publication volume, its average citation count is the highest among the top ten institutions by publication volume, indicating the high quality and academic influence of its research output. At the author level, the top 11 authors by publication volume are mainly from Japan, Turkey, and the U.S. Five of the Turkish authors are from Hacettepe University, suggesting they may belong to 1 or more closely collaborative research teams. Of particular note are Takashi Abe, Jeremy P. Loenneke, and Robert S. Thiebaud from the University of Mississippi, who have demonstrated outstanding performance in publication volume, average citations, h-index, and g-index, showing significant academic influence in this field. By analyzing countries, institutions, and authors, this study can provide a reference for researchers to identify potential collaborators and accurately track the latest research trends. However, current research in this field is still highly concentrated in developed countries, with a significant lack of research data from regions like Africa. In the future, it is urgent to promote more globally representative collaborative research, especially in resource-limited areas, to facilitate the balanced global development of the ultrasound assessment system for sarcopenia.

A comprehensive evaluation of the publication volume and influence of journals in the field of ultrasound and sarcopenia provides valuable references for researchers seeking to publish their work and track academic frontiers. The overall analysis shows that journals with a high publication volume in this field are mainly concentrated in geriatrics, nutrition, and muscle-related areas. Nutrients, Journal of Cachexia Sarcopenia and Muscle, and Scientific Reports rank in the top 3 for publication volume. While publication volume can, to some extent, reflect a journal interest in a specific field, it may also be influenced by the journal publishing strategy and other factors, making it insufficient to fully represent its long-term academic influence. IF, h-index, and g-index are widely recognized indicators of a journal academic influence. The Journal of Cachexia Sarcopenia and Muscle performs excellently in IF, h-index, and g-index, demonstrating its significant publication scale and academic influence in this field. Additionally, journals such as Nutrients, Archives of Gerontology and Geriatrics, Aging Clinical and Experimental Research, Clinical Nutrition, Clinical Interventions in Aging, and Experimental Gerontology also show high h-indices and g-indices, providing reliable publication options for researchers in this field.

4.2. Thematic evolution and emerging research frontiers

Ultrasound, as a noninvasive, portable, and highly reproducible imaging technology, has been widely applied in the diagnostic research of sarcopenia. Currently, ultrasound primarily assesses muscle mass and quantity by measuring lower limb muscles, such as the rectus femoris, gastrocnemius, and quadriceps femoris, with relatively less use of upper limb and trunk muscles.^[17] B-mode ultrasound is mainly used to evaluate muscle morphology and structure, such as muscle thickness and cross-sectional area.^[27] Research shows that among numerous ultrasound measurement parameters, muscle thickness is the most widely used indicator, followed by cross-sectional area and echo intensity.^[17] One meta-analysis found that, based on the recognized EWGSOP2 and AWGS2 diagnostic criteria, the muscle thickness of the rectus femoris has the highest area under the curve in diagnosing sarcopenia in older adults.^[28] However, another meta-analysis based on a wider range of diagnostic criteria (e.g., EWGSOP1, EWGSOP2, AWGS 2014, AWGS 2019, the International Working Group on Sarcopenia, the Foundation for the National Institutes of Health Sarcopenia Project, etc.) noted that the diagnostic accuracy of muscle thickness for muscles like the gastrocnemius and rectus femoris is only moderate. This study also suggested that combining muscle quantity indicators (such as cross-sectional area) with muscle quality indicators (such as echo intensity), for example, the combination of cross-sectional area and echo intensity of the biceps brachii or rectus femoris, is superior to using a single indicator alone, which indicates that multi-parameter combined assessment may provide higher diagnostic accuracy.^[17] Nevertheless, there is still variability in the diagnostic accuracy of ultrasound for sarcopenia, which may be related to various factors such as the study population, the muscle being measured, the choice of ultrasound parameters, and the diagnostic reference standard. Furthermore, the accuracy of ultrasound diagnosis is highly dependent on the operator experience, which can lead to inconsistent results, and the qualitative or quantitative analysis of images is time-consuming, all of which limit its widespread clinical adoption.

To overcome the limitations of traditional ultrasound, researchers have begun exploring new ultrasound technologies, particularly the application of SWE in sarcopenia diagnosis.^[29–31] Muscle changes caused by disease or aging, such as fibrosis or increased intramuscular fat tissue, lead to changes in muscle stiffness. SWE can assess muscle quality by quantifying muscle stiffness and has high reliability and reproducibility.^[32] One study evaluated the incidence of sarcopenia in patients with type 2 diabetes by measuring the SWE of the medial gastrocnemius muscle and considered SWE a valuable tool for objectively assessing sarcopenia in this population.^[30] However, the translation of SWE from a research tool to a clinical application still faces significant challenges. First, there is a lack of diagnostic standardization, making it difficult to establish reliable normative reference values. Second, there is currently a lack of large-scale validation studies to support its widespread use.^[33] Future validation studies should include large-scale multicenter cohorts to establish population-specific reference ranges, comparisons with established diagnostic standards (e.g., DXA, CT, AWGS/EWGSOP criteria) to determine optimal thresholds, longitudinal studies to evaluate prognostic value, and reproducibility analyses across operators and devices. These efforts are essential to support the clinical implementation of SWE in sarcopenia assessment.

Given the shortcomings of traditional ultrasound in efficiency and standardization, researchers have begun to explore AI-assisted ultrasound diagnosis in an attempt to overcome these bottlenecks.^[34,35] For instance, Zi-Tong Chen et al developed a convolutional neural network model based on muscle ultrasound images, which was proven to be a superior sarcopenia screening tool. When this model was combined with clinical and laboratory data, its diagnostic performance was further enhanced.^[34] Additionally, another study has shown that combining ultrasound radiomics with machine learning can significantly improve the diagnostic accuracy of sarcopenia in nursing home residents.^[36] Despite the great potential of AI, research in this area remains in its early stages. Key challenges that must be addressed to enhance assessment accuracy and clinical applicability include algorithm optimization, improved image processing techniques, large-scale sample validation, and strengthened interdisciplinary collaboration.

Among various body composition assessment methods, BIA and ultrasound are favored for their low cost, high portability, and bedside usability. Currently, the AWGS 2019 consensus provides cutoff values for diagnosing sarcopenia using BIA.^[26] However, ultrasound examination for sarcopenia diagnosis still lacks a validated protocol or cutoff values. Therefore, researchers often compare ultrasound parameters with BIA as a reference standard to evaluate ultrasound discriminatory ability and correlation in sarcopenia diagnosis. Multiple studies have explored this.^[37–39] Moreover, some researchers are starting to combine BIA and ultrasound metrics to more comprehensively assess a patient sarcopenia status. For example, 1 study designed a muscle quality index that combines cross-sectional area and PhA, which performed better than using any single indicator alone in diagnosing sarcopenia.^[40] This suggests that combining parameters from different technologies may offer a superior solution for the diagnosis and assessment of sarcopenia. Notably, the combination of BIA-derived PhA and ultrasound-measured cross-sectional area could serve as a pragmatic bedside protocol. BIA-derived PhA reflects cellular integrity and nutritional status, while ultrasound-derived cross-sectional area or muscle thickness provides structural information on muscle quantity. Integrating these complementary parameters may facilitate rapid screening and risk stratification in clinical settings, particularly in hospitals, rehabilitation units, and community care environments. Future studies should develop simplified bedside algorithms that integrate ultrasound measurements with BIA indicators to enhance feasibility, reduce assessment time, and support clinical decision-making.

Furthermore, the keyword analysis results of this study show that “ultrasound-sarcopenia” research is no longer limited to the traditional scope of geriatrics but has formed a research cluster centered on “older adults” and “aging” and radiating to various other chronic systemic diseases, such as sarcopenic obesity, nonalcoholic fatty liver disease, liver fibrosis, chronic kidney disease, heart failure, head and neck cancer, and disease-related malnutrition. The formation of this research cluster reflects that sarcopenia is not merely a single muscle problem but a systemic syndrome related to multi-systemic dysfunction, and its research scope is continuously broadening. Recent studies have found that multiple diseases can induce the onset of sarcopenia, and conversely, sarcopenia can affect the prognosis of these diseases. For example, disease-related malnutrition is increasingly prevalent in older patients and those with multiple comorbidities, characterized by insufficient nutritional intake leading to changes in body composition (e.g., reduced muscle mass) and a decline in physical function, which may ultimately trigger sarcopenia.^[41] Especially in cancer patients, the prevalence of disease-related malnutrition is as high as 50–80%, and it is more severe in older patients and those with upper gastrointestinal, head and neck, or lung cancer.^[41] In addition, as research deepens, the role of sarcopenia in the pathological processes of diseases like nonalcoholic fatty liver disease and liver fibrosis has also been progressively revealed.^[42] Regarding the clinical feasibility of detection devices, MRI and CT are not suitable as routine clinical practice tools due to their high cost and lack of portability; DXA has limited accessibility globally (especially in developing countries in Asia); and the diagnostic cutoff values for BIA are population- and device-dependent, which restricts its universality. In contrast, ultrasound, with its portability and ease of access, is becoming an ideal choice for sarcopenia screening and assessment.^[20] Therefore, exploring standardized methods for ultrasound diagnosis of sarcopenia and its application in different scenarios is crucial for promoting this technology.

4.3. Suggestions for future research

Based on the findings of this bibliometric analysis, future research should prioritize several directions to advance the clinical application of ultrasound in sarcopenia. First, standardized scanning protocols and population-specific cutoff values should be established through large-scale, multicenter prospective studies, enabling ultrasound to transition from a complementary tool to a primary diagnostic modality. Second, the clinical translation of advanced technologies, particularly SWE and ultra-high-frequency ultrasound, should be further explored to provide more refined qualitative information on muscle stiffness and microarchitecture. Third, the integration of AI and radiomics should be accelerated to automate image analysis, reduce operator dependency, and identify novel imaging biomarkers of muscle quality.

In addition, future studies should adopt longitudinal designs to evaluate ultrasound sensitivity in monitoring intervention responses, such as nutritional and exercise therapies, and explore the synergistic value of multimodal assessment strategies combining ultrasound with BIA or biochemical markers. To promote global equity, research collaborations should be extended to underrepresented regions, including Africa and Southeast Asia, to validate the generalizability of ultrasound-based diagnostic frameworks across diverse populations. Addressing the underrepresentation of Africa and other low- and middle-income countries requires equity-focused collaborative strategies, such as establishing international multicenter research networks, promoting technology transfer and structured training programs, and developing simplified, low cost protocols suitable for resource-limited settings. Furthermore, global initiatives should prioritize data-sharing platforms and joint cohort studies to enhance the generalizability of diagnostic criteria across diverse healthcare systems. These efforts may help reduce global disparities and support broader clinical implementation of ultrasound-based sarcopenia assessment.

Given the superiority of multi-parameter assessment over single indicators, future studies should also aim to develop standardized composite indices for ultrasound-based sarcopenia evaluation. Integrating parameters such as muscle thickness, cross-sectional area, echo intensity, and stiffness (e.g., SWE) into a unified muscle quality score may improve diagnostic accuracy and clinical usability. These composite indices should be validated against established diagnostic criteria and clinical outcomes to determine their predictive value. The development of standardized scoring systems may further facilitate clinical implementation and improve comparability across studies.

5. Limitations

First, it is important to acknowledge the inherent methodological constraints of bibliometric analysis. Although this study offers a quantitative summary of publication trends, it cannot fully capture the qualitative depth of the research. Aspects such as a study novelty, the clinical relevance of its findings, and the rigor of its design are not adequately reflected in publication or citation metrics. Moreover, the dataset used here is restricted to the WoSCC, which may omit relevant literature available in other databases, such as Scopus or PubMed.

6. Conclusions

This bibliometric analysis reveals that ultrasound-based sarcopenia research is evolving rapidly. The marked increase in publications since 2018 is largely driven by key international diagnostic consensuses. Geographically, the field shows a multipolar pattern: Japan, the U.S., and China lead in publication volume, while Western nations demonstrate stronger collaborative influence. Methodologically, traditional B-mode ultrasound parameters remain foundational, but advanced techniques such as SWE and AI are being actively explored to enhance diagnostic accuracy and overcome limitations related to operator dependency and standardization. Research focus is also broadening from geriatric populations to various chronic systemic diseases, underscoring the systemic nature of sarcopenia and its prognostic relevance. Despite ultrasound demonstrated potential, challenges remain in standardization and clinical application, and no single parameter currently enables precise assessment. Future research should prioritize multimodal integration: combining ultrasound parameters with clinical data, laboratory indicators, and AI analysis: to build more accurate assessment models. The ultimate goal is to develop a portable, scalable screening protocol for early sarcopenia detection and intervention in community and primary care settings, thereby improving patients’ quality of life and reducing public health burdens.

Take-home messages for practical applications and training practices:

• [1]Ultrasound is a promising and portable tool for sarcopenia screening, particularly suitable for bedside and community settings.
• [2]Standardized scanning protocols and structured training programs are essential to improve measurement reliability.
• [3]Multi-parameter ultrasound assessment is preferable to single parameter evaluation.
• [4]Integration of ultrasound with clinical and functional assessments may improve diagnostic accuracy.
• [5]Emerging technologies such as SWE and AI should be incorporated into future training and clinical practice.

Author contributions

Formal analysis: Xueling Ma, Chao Yuan.

Methodology: Xueling Ma, Chao Yuan.

Writing – original draft: Xueling Ma, Chao Yuan.

Conceptualization: Guoqing Zhang, Jiaguo Huang.

Funding acquisition: Guoqing Zhang.

Supervision: Guoqing Zhang, Jiaguo Huang.

Writing – review & editing: Guoqing Zhang, Jiaguo Huang.