Analysis of various parameters affecting signals in resting-state mouse brain photoacoustic microscopy: A simulation study

Photoacoustic imaging is an emerging modality which is being developed due to its high capabilities. At the other hand, one of the most interesting areas of research is brain imaging. Photoacoustic imaging has been used in brain imaging due to its capability of both functional and anatomical imaging. Photoacoustic spectral analysis is one of the last research areas in this field. But, as our point of view, only looking to frequency components of photoacoustic signals doesn't make all available required data. Thus, in this work, our study presents both time-domain and frequency-domain analysis of photoacoustic signals and demonstrates that going deeper through the brain will decrease contrast and resolution of photoacoustic microscopy system for imaging of resting-state mouse brain vasculature and this can be solved by using an exogenous contrast agent like Indocyanine Green. Also, by using analysis of photoacoustic signals, we demonstrated that Indocyanine Green will increase both depth resolution and contrast. Also, simulations and analysis done on different sizes of hemoglobin absorber containers demonstrated that there is a need to ultra-broadband transducers for reaching more precise analysis of photoacoustic signals, and this means Acoustic-Resolution Photoacoustic Microscopes are less efficient for being used for spectral analysis.