fig2
![Theranostic extracellular vesicles: a concise review of current imaging technologies and labeling strategies](https://image.oaes.cc/568c3a1f-8d1e-41f9-8faf-0f79596dee31/5567.fig.2.jpg)
Figure 2. Milestones in EV imaging. Keywords including “exosome” or “extracellular vesicle”, and imaging modalities were referenced in PubMed (https://pubmed.ncbi.nlm.nih.gov/) to obtain articles that employed a particular imaging technology for the first time to observe EVs. The bar graph represents the total number of publications on EV research per year.