Ultra-compact micro-photoacoustic tomography for brain imaging in vivo

Applied Physics Letters, Volume 119, Issue 21, November 2021. In vivo wide-field brain microscopy has remained a non-trivial challenge in life science research, which would provide indispensable preclinical insight into the whole-brain metabolism and hemodynamic. Here, we developed an ultra-compact micro-photoacoustic tomography (μPAT) system for fast brain imaging equipped with a 10 MHz 256-element full-ring ultrasound transducer array and 100 MS/s/ch multi-channel parallel data acquisition. The system design and calibration are presented in detail, along with the 62 μm in-plane resolution comparable to the level of acoustic-resolution photoacoustic microscopy. The μPAT system provided the ability to noninvasively use high-resolution mapping of the microvascular network of the full-view brain at different depths, cerebral ischemia, and intracerebral foreign-body. Ultra-compact μPAT holds great potential to take the technology out of the lab for preclinical imaging and clinical translation.