Optoacoustic tomography (OAT), also known as photoacoustic tomography, is arapidly emerging hybrid imaging technique that possesses great potential for awide range of biomedical imaging applications. In OAT, a laser is employed toilluminate the tissue of interest and acoustic signals are produced via thephotoacoustic effect. From these data, an estimate of the distribution of theabsorbed optical energy density within the tissue is reconstructed, referred toas the object function. This quantity is defined, in part, by the distributionof light fluence within the tissue that is established by the laser source.When performing three-dimensional imaging of large objects, such as a femalehuman breast, it can be difficult to achieve a relatively uniform coverage oflight fluence within the volume of interest when the position of the lasersource is fixed. To circumvent this, researchers have proposed illuminationschemes in which the relative position of the laser source and ultrasound probeis fixed, and both are rotated together to acquire a tomographic data set. Aproblem with this rotating-illumination scheme is that the tomographic data areinconsistent; namely, the acoustic data recorded at each tomographic view angle(i.e., probe position) are produced by a distinct object function. In thiswork, the impact of this data inconsistency on image reconstruction accuracy isinvestigated systematically. This is accomplished by use of computer-simulationstudies and application of mathematical results from the theory of microlocalanalysis. These studies specify the set of image discontinuities that can bestably reconstructed with a non-stationary optical illumination set-up. Thestudy also includes a comparison of the ability of iterative and analytic imagereconstruction methods to mitigate artifacts attributable to the datainconsistency.
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