Implementation and comparison of reconstruction algorithms for two-dimensional optoacoustic tomography using a linear array

Our goal is to compare and contrast various image reconstruction algorithms for optoacoustic tomography (OAT) assuming a finite linear aperture of the kind that arises when using a linear-array transducer. Because such transducers generally have tall, narrow elements, they are essentially insensitive to out-of-plane acoustic waves, and the usually 3-D OAT problem reduces to a 2-D problem. Algorithms developed for the 3-D problem may not perform optimally in 2-D. We have implemented and evaluated a number of previously described OAT algorithms, including an exact (in 3-D) Fourier-based algorithm and a synthetic-aperture-based algorithm. We have also implemented a 2-D algorithm developed by Norton for reflection mode tomography that has not, to the best of our knowledge, been applied to OAT before. Our simulation studies of resolution, contrast, noise properties, and signal detectability measures suggest that Norton's approach-based algorithm has the best contrast, resolution, and signal detectability.