Ring-shaped confocal photoacoustic computed tomography for small-animal whole-body imaging

We report herein a novel three-dimensional photoacoustic computed tomography (PACT) system for small-animal whole-body imaging. The PACT system, based on a 512-element full-ring ultrasonic transducer array, was cylindrically focused and capable of forming a two-dimensional image in 1.6 seconds. The pulsed laser could either illuminate directly from the top or be reshaped to illuminate the sample from the side. Top illumination was mainly used for mouse brain and mouse embryo imaging. Side illumination provided in vivo anatomical images of an adult mouse. By translating the mouse along the elevational direction, the system provided serial cross-sectional images