Photoacoustic imaging holds great clinical promise because it achieves high-resolution tomographic imaging at depths. Moreover, its strong spectroscopic imaging capability provides a wealth of molecular and functional information based on. Still, despite recent advances, existing photoacoustic systems cannot be readily applied in the clinical environment. This dissertation aims to push the frontier of clinical photoacoustic imaging from both technological and applicational perspectives.
The first part of this dissertation describes the development of photoacoustic endoscopy (PAE) systems for imaging human Barrett\u27s esophagus and studying preterm birth. We have developed optical resolution-PAE, which significantly improved lateral resolutions, laparoscopic-PAE, which can guide minimally-invasive surgeries, and catheter-based-PAE, which opens up new opportunities to image the human esophagus. For each system, we tested and optimized the imaging performance in phantom and animal experiments, and then validated them in humans.
The second part of the dissertation describes advanced photoacoustic imaging aided by contrast agents. Specifically, gold nanoparticles were used to quantify biological diffusion photoacoustically. In addition, ion nanosensors were applied for continuously monitoring therapeutic lithium concentration in deep tissue in vivo
