ABSTRACT
This chapter presents a ring-shaped virtual point detector and demonstrates its application in photoacoustic tomography (PAT). The virtual point detector provides PAT with the advantages of a real point detector, that is, high spatial resolution that is uniform throughout the field of view. At the same time, it has a larger actual size and produces lower thermal noise than a real point detector. The chapter analyzes the principle of the virtual point detector, then presents simulation and experimental data, and discusses the results. The virtual point detector provides omni-directional detection, which means that the detection is free of any aperture effect. Being the center of a physical ring, the virtual point detector can be scanned along a track inside a physically inaccessible medium to improve the resolution and signal-noise ratio (SNR). The virtual point detector can also be potentially used in other ultrasound-related technologies such as ultrasound tomography or pulse-echo-based ultrasonography.
