FIGURE 5.
A, Schematic overview of photoacoustic imaging principle; after injection of a tumor-targeting agent the imaging agent will target tumor cells and produces an enhanced photoacoustic signal, after excitation with a laser. The agent can target the cancer at multiple locations depending on the size; e.g. intravascular, receptors on the cell membrane, or intracellular. B, Top: Schematic overview showing the principle of photoacoustic imaging; the thermo-elastic expansion caused by heating of the tissue due to the laser will lead to acoustic waves that can be converted into both ultrasound and molecular images. Bottom: Tumor-targeted photoacoustic imaging. Mice bearing FTC133 tumors were photoacoustically imaged using 680 and 750 nm light before and after the injection of a MMP-targeting probe [From Levi et al, 2013134].