California Institute Of Medical Science

Photoacoustic computed tomography (PACT) reveals biological structures, pharmacokinetics, and physiological functions. Although a premium PACT system with many ultrasound (US) transducers delivers high‐quality volumetric imaging, it suffers from high system costs and slow temporal resolution. Here, using a limited number of US elements, a hybrid diffusion model (HD‐PACT) is demonstrated that enhances dynamic multiparametric (structural, functional, and contrast‐enhanced) 3D PACT. Using just 256 out of the 1024 elements in a premier hemispherical US array for PACT, HD‐PACT improves structural images acquired in different planes, organisms, and wavelengths. In functional imaging, HD‐PACT enables 256‐element PACT to observe hypoxia, pharmacokinetics, and angiogenesis during tumor progression. Lastly, HD‐PACT is transferable to low‐end PACT (only 128 US elements), where it dynamically captures contrast‐free/enhanced organs, oxygen‐perturbed brains, and cardiac dynamics with high spatiotemporal resolution in live animals. It is believed that HD‐PACT will be valuable in oncology, cardiology, pharmacology, and endocrinology.