Bibliometric Analysis of Global Research Trends on Ultrasound Microbubble: A Quickly Developing Field

Abstract

Background: Microbubbles are widely used as highly effective contrast agents to improve the diagnostic capability of ultrasound imaging. Mounting evidence suggests that ultrasound coupled with microbubbles has promising therapeutic applications in cancer, cardiovascular, and neurological disorders by acting as gene or drug carriers. The aim of this study was to identify the scientific output and activity related to ultrasound microbubble through bibliometric approaches.Methods: The literature related to ultrasound microbubble published between 1998 and 2019 was identified and selected from the Science Citation Index Expanded of Web of Science Core Collection on February 21, 2021. The Scopus database was also searched to validate the results and provided as supplementary material. Quantitative variables including number of publications and citations, H-index, and journal citation reports were analyzed by using Microsoft Excel 2019 and GraphPad Prism 8.0 software. VOS viewer and CiteSpace V were used to perform coauthorship, citation, co-citation, and co-occurrence analysis for countries/regions, institutions, authors, and keywords.Results: A total of 6088 publications from the WoSCC were included. The United States has made the largest contribution in this field, with the majority of publications (2090, 34.3%), citations (90,741, 46.6%), the highest H-index (138), and close collaborations with China and Canada. The most contributive institution was the University of Toronto. Professors De Jong N and Dayton P A have made great achievements in this field. However, the research cooperation between institutions and authors was relatively weak. All the studies could be divided into four clusters: “ultrasound diagnosis study,” “microbubbles’ characteristics study,” “gene therapy study,” and “drug delivery study.” The average appearing years (AAY) of keywords in the cluster “drug delivery study” was more recent than other clusters. For promising hot spots, “doxorubicin” showed a relatively latest AAY of 2015.49, followed by “nanoparticles” and “breast cancer.”Conclusion: There has been an increasing amount of scientific output on ultrasound microbubble according to the global trends, and the United States is staying ahead in this field. Collaboration between research teams still needs to be strengthened. The focus gradually shifts from “ultrasound diagnosis study” to “drug delivery study.” It is recommended to pay attention to the latest hot spots, such as “doxorubicin,” “nanoparticles,” and “breast cancer.”

Current State and Future Directions of Intranasal Delivery Route for Central Nervous System Disorders: A Scientometric and Visualization Analysis

“…H-index, defined as the number of papers with citation number ≥ h, is an important indicator to simultaneously characterize the quality and quantity of scientific output (Hirsch, 2005;Merigó and Yang, 2017). Thus, it is one of the dominant metrics for quantifying the productivity and impact of an author, a country or an institution (De-Castilhos-Ghisi et al, 2020;Wu et al, 2021a). Our study revealed that the United States was the leading country both in the total number of publications and H-index.…”

“…In this study, CiteSpace was used to conduct research cooperation relationships of institutions, co-occurring network of subject categories, the dual-map overlay of journals, reference and keyword bursts. The indicator of betweenness centrality of a node can measure the importance of each node in the network, and the node with a higher centrality is commonly considered as a key point or pivotal turning point in the field (Wu et al, 2021a;Wu et al, 2021b). For additional detailed information about CiteSpace software, a manual is available at http://cluster.ischool.…”

“…An academic journal distribution analysis is helpful for scholars to determine the dominant journals in a certain field, and to select the most appropriate scientific journals for publication of their research results (Li et al, 2021;Wu et al, 2021a). Thus, we have listed the 10 journals with the most publications related to intranasal administration research in Table 3.…”

“…Citation counts is a commonly used evaluation metric of scientometric analysis to quantify the relative impact of scientific papers in a subject area, as the influence and recognition of a paper is usually proportional to number of citations that the paper received (Li et al, 2021;Wu et al, 2021a). It is often assumed that highly-cited publication refers to high-quality studies with great influence and innovation in a certain field, which is also regarded as the knowledge base and essential readings for scholars wishing to engage in this field.…”

“…Consequently, numerous studies have proposed promising strategies to improve the delivery of therapeutic agents to the brain by circumventing or overcoming the BBB during the last decades. These strategies include intracerebroventricular injections (Lopachev et al, 2019), convection enhanced delivery (Zhan and Wang, 2018), inhibition of efflux transporters (Sanchez-Covarrubias et al, 2014), chemical modification (Al-Ahmady, 2018), and the application of hyperosmotic agents (Patel et al, 2009) or focused ultrasound (Dauba et al, 2020;Lin et al, 2020;Wu et al, 2021a), and so on. However, the limitation of these administration routes is marred by safety concerns, invasive, and erratic efficacy.…”