Prospects of molecular photoacoustic imaging at 1064 nm wavelength

An analysis of the photoacoustic (PA) signal from murine tissue in vivo revealed several benefits of contrastenhanced PA imaging at a wavelength of 1064 nm. Of all the wavelengths tested in a range from 710 to 1064 nm, the background PA signal from tissue in vivo was lowest and more homogeneous at 1064 nm. For blood-laden tissue, the background PA signal was up to 70% less at 1064 nm. Furthermore, when plasmonic nanoparticles, such as silver nanoplates, were introduced in vivo as contrast agents, the contrast in PA images at 1064 nm increased 38% compared to 750 nm. Therefore, contrast-enhanced PA imaging at 1064 nm is advantageous because of the low and homogeneous signal from native tissue, enabling high contrast in PA imaging when exogenous, molecularly targeted agents are employed.