Noninvasive in vivo monitoring of collagenase induced intracerebral hemorrhage by photoacoustic tomography.

Photoacoustic tomography (PAT) is an emerging noninvasive biomedical imaging modality that can be used for visualizing the structure and function of brain in high resolution. Here we report an application of PAT to imaging intracerebral hemorrhage (ICH) in a mouse model. In vivo photoacoustic images were obtained in mice with right basal ganglia hemorrhage induced by microinjection of collagenase. With multi-spectral light excitation, cortical vascular network was clearly revealed at 532 nm, and ICH associated hematoma lesions and perihemmatoma regions were accurately mapped over time at 750 nm and 875 nm, respectively. Our results suggest that PAT provides a unique tool for visualizing hemodynamics involved in brain diseases such as ICH.