Figure 1: Laser optoacoustic imaging system 3D-brain images of ultra-small paramagnetic iron oxide nanoparticles (USPIO) treated rat brain obtained with the laser wavelength at 532 nm. (a) Before and (b) after administration of USPIO contrast agent (c) magnetic resonance image of (CLUSPIO) treated rat brain. T2* protocol reveals the hypointensities (note regions delimited by ellipsoids) allegedly caused by CLUSPIO seen with time to echo (TE) 25 ms. (d) Signal enhancement highlighting accumulation of iron oxide nanoparticles, bright structures, observed in tissues from CLUSPIO-treated ALS animals using surface enhanced nanoimaging based on stimulated vibrational microscopy