13
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The characterization of an economic and portable LED-based photoacoustic imaging system to facilitate molecular imaging

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Graphical abstract

          Highlights

          • We characterized a commercially available LED-based photoacoustic imaging system.

          • The LED beam profile, spatial/temporal resolution, and penetration depth were measured.

          • Indocyanine green and methylene blue were utilized as exogenous contrast agent, and their detection limits were calculated.

          • The capability for in vivo experiments was demonstrated using human mesenchymal stem cells labeled with a near-infrared dye (DiR) in living mice.

          Abstract

          Photoacoustic imaging (PAI) is a non-invasive, high-resolution hybrid imaging modality that combines optical excitation and ultrasound detection. PAI can image endogenous chromophores (melanin, hemoglobin, etc.) and exogenous contrast agents in different medical applications. However, most current equipment uses sophisticated and complicated OPO lasers with tuning and stability features inconsistent with broad clinical deployment. As the number of applications of PAI in medicine increases, there is an urgent need to make the imaging equipment more compact, portable, and affordable. Here, portable light emitting diode – based photoacoustic imaging (PLED-PAI) was introduced and characterized in terms of system specifications, light source characterizations, photoacoustic spatial/temporal resolution, and penetration. The system uses two LED arrays attached to the sides of a conventional ultrasound transducer. The LED pulse repetition rate is tunable between 1 K Hz, 2 K Hz, 3 K Hz, and 4 K Hz. The axial resolution was 0.268 mm, and the lateral resolution was between 0.55 and 0.59 mm. The system could detect optical absorber (pencil lead) at a depth of 3.2 cm and the detection limits of indocyanine green (ICG) and methylene blue (MB) were 9 μM and 0.78 mM. In vivo imaging of labeled human mesenchymal stem cells was achieved to confirm compatibility with small animal imaging. The characterization we report here may have value to other groups evaluating commercially available photoacoustic imaging equipment.

          Related collections

          Most cited references39

          • Record: found
          • Abstract: found
          • Article: not found

          Contrast agents for molecular photoacoustic imaging.

          Photoacoustic imaging (PAI) is an emerging tool that bridges the traditional depth limits of ballistic optical imaging and the resolution limits of diffuse optical imaging. Using the acoustic waves generated in response to the absorption of pulsed laser light, it provides noninvasive images of absorbed optical energy density at depths of several centimeters with a resolution of ∼100 μm. This versatile and scalable imaging modality has now shown potential for molecular imaging, which enables visualization of biological processes with systemically introduced contrast agents. Understanding the relative merits of the vast range of contrast agents available, from small-molecule dyes to gold and carbon nanostructures to liposome encapsulations, is a considerable challenge. Here we critically review the physical, chemical and biochemical characteristics of the existing photoacoustic contrast agents, highlighting key applications and present challenges for molecular PAI.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            A Brain Tumor Molecular Imaging Strategy Using A New Triple-Modality MRI-Photoacoustic-Raman Nanoparticle

            The vexing difficulty in delineating brain tumor margins represents a major obstacle toward better outcome of brain tumor patients. Current imaging methods are often limited by inadequate sensitivity, specificity, and spatial resolution. Here we show that a unique triple-modality Magnetic resonance imaging - Photoacoustic imaging – surface enhanced Raman scattering (SERS) nanoparticle (MPR) can accurately help delineate the margins of brain tumors in living mice both pre- and intra-operatively. The MPRs were detected by all three modalities with at least picomolar sensitivity both in vitro and in living mice. Intravenous injection of MPRs into glioblastoma-bearing mice led to specific MPR accumulation and retention by the tumors, allowing for non-invasive tumor delineation by all three modalities through the intact skull. Raman imaging allowed guidance of intra-operative tumor resection, and histological correlation validated that Raman imaging is accurately delineating brain tumor margins. This novel triple-modality nanoparticle approach holds promise to enable more accurate brain tumor imaging and resection.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Biomedical applications of photoacoustic imaging with exogenous contrast agents.

              Photoacoustic imaging is a biomedical imaging modality that provides functional information, and, with the help of exogenous contrast agents, cellular and molecular signatures of tissue. In this article, we review the biomedical applications of photoacoustic imaging assisted with exogenous contrast agents. Dyes, noble metal nanoparticles, and other constructs are contrast agents which absorb strongly in the near-infrared band of the optical spectrum and generate strong photoacoustic response. These contrast agents, which can be specifically targeted to molecules or cells, have been coupled with photoacoustic imaging for preclinical and clinical applications ranging from detection of cancer cells, sentinel lymph nodes, and micrometastasis to angiogenesis to characterization of atherosclerotic plaques. Multi-functional agents have also been developed, which can carry drugs or simultaneously provide contrast in multiple imaging modalities. Furthermore, contrast agents were used to guide and monitor the therapeutic procedures. Overall, photoacoustic imaging shows significant promise in its ability to assist in diagnosis, therapy planning, and monitoring of treatment outcome for cancer, cardiovascular disease, and other pathologies.
                Bookmark

                Author and article information

                Contributors
                Journal
                Photoacoustics
                Photoacoustics
                Photoacoustics
                Elsevier
                2213-5979
                26 November 2017
                March 2018
                26 November 2017
                : 9
                : 10-20
                Affiliations
                [a ]Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92092, United States
                [b ]Shiley Eye Institute, Department of Ophthalmology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92092, United States
                [c ]Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92092, United States
                [d ]Department of Radiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92092, United States
                Author notes
                [* ]Corresponding author at: Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92092, United States. jjokerst@ 123456ucsd.edu
                Article
                S2213-5979(17)30020-4
                10.1016/j.pacs.2017.11.001
                5723278
                29234601
                8ce4ef43-b82c-489a-95af-ad93b01b3ba8
                © 2017 The Authors

                This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

                History
                : 27 April 2017
                : 6 November 2017
                : 19 November 2017
                Categories
                Research Article

                portable photoacoustic imaging,led,optoacoustic imaging,molecular imaging

                Comments

                Comment on this article