Figure 6.

Multiwavelength in vivo photoacoustic showing spectral dependence of INDT-BT nanoparticles (SPN4) and vasculature: Subsample of photoacoustic images (a) before and (b) after subcutaneous injection of a 10 μL solution, containing 1.6 μg of SPN4, into the flank of a SCID mouse. x-y MIPs (top rows, area 14 × 14 mm²) and y-z MIPs (bottom rows, area 14 × 6 mm²) acquired at different excitation wavelengths are shown. (c) Normalized wavelength dependence of SPN4 absorption from the in vivo photoacoustic images shown in (b), normalized in vitro PA spectra of SPN4 and the normalized specific absorption of oxyhemoglobin and deoxyhemoglobin.