Development of Photoacoustic Tomography Technologies for Preclinical Application

As a novel imaging modality that combines optical excitation with acoustic detection, photoacoustic tomography (PAT) offers high resolution and deep tissue imaging of animal and human, based on either endogenous or exogenous contrast agents. As a useful biomedical imaging tool, PAT has been developed rapidly over the past few years. In this dissertation, we have further facilitated the development of PAT in the following three aspects: finer spatial resolution, better imaging system, and higher imaging contrast. There are 5 chapters in this dissertation. Chapter 1 is the introduction, which gives backgrounds on PAT, and introduces the novelty of this dissertation. Chapter 2 discusses a coherent-weighted (CoW) based three-dimensional (3D) reconstruction algorithm to improve elevation resolution in linear transducer array-based PAT systems. Chapter 3 introduces two new PAT systems. One is the compact, ultrafast laser-based PAT system that enables deep tissue imaging in animal and human. The other is the multiphoton PAT system through upconversion energy transfer, which allows visible contrast agents to be photoacoustically detected in deep tissue under near infrared (NIR) excitation. Chapter 4 describes high-contrast PAT, and presents various photoacoustic applications of two exogenous contrast agents. Conclusion and discussions about the future continuation of these works are presented in Chapter 5. With promising results shown in this dissertation, PAT is expected to find more applications in both preclinical and clinical imaging.