ABSTRACT
This chapter reviews the currently used reconstruction algorithms for real-time photoacoustic imaging with a linear array transducer, and explains the theoretical background for optimization of the irradiation geometry. It demonstrates the potential of a combined photoacoustic/echo-ultrasound imaging device for the characterization of small tissue structures. In contrast to echo-ultrasound imaging, which is based on acoustical tissue properties, photoacoustic imaging is based on optical tissue properties. In order to exploit efficiently the advantages of the photoacoustic modality in ultrasound imaging, special image processing algorithms suited for the combined visualization of information have to be developed. It is clear that in the case of blood vessel imaging, the echo-ultrasound and the photoacoustic modality give different results, depending on the size and the spatial orientation of the vessels. The geometry of irradiation is crucial when photoacoustic signals are acquired with a linear array transducer.
