Spiral volumetric optoacoustic tomography (SVOT) of mice from head to tail

Small animal preclinical research is indispensable to study human disease progression and to monitor potential treatment therapies. Optoacoustic tomography has been recognized as a powerful imaging modality for preclinical whole-body imaging of rodents. In particular, spiral volumetric optoacoustic tomography (SVOT) capitalizes on the large angular coverage of a spherical transducer array to provide otherwise-unattainable optoacoustic images of mice. However, only thoracic and/or abdominal regions of the animal could be imaged with this approach. Efficient whole-body coverage indeed demands continuous acoustic coupling between the animal and the detector surface. In this work, we implement panoramic (360⁰) head-to-tail imaging of mice with SVOT combined with multi-beam illumination. For this, a dedicated animal holder enables uninterrupted acoustic coupling for whole-body scans. Proper coverage of cranial regions in addition to thoracic and abdominal regions is then feasible in a single set up. Self-gated motion rejection and dual speed-of-sound correction algorithms were employed to optimize the image fidelity. The developed system is highly suitable for label-free imaging of hemodynamics across individual organs, total body accumulation and clearance dynamics of molecular agents and drugs, as well as for monitoring responses to stimuli with unparalleled contrast and spatio-temporal resolution.