title: Contrast agents for molecular photoacoustic imaging.
abstract: 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.
authors.affiliation: Department of Physics, University of Cambridge, Cambridge, UK.|Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
authors.forename: Judith
authors.initials: J
authors.lastname: Weber
authors.affiliation: Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Beard
authors.affiliation: Department of Physics, University of Cambridge, Cambridge, UK.|Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
authors.forename: Sarah E
authors.identifier: 0000-0003-0371-8635
authors.initials: SE
authors.lastname: Bohndiek
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry; D061088:Photoacoustic Techniques / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D003287:Contrast Media