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    Diffraction tomography (DT) is a well-known method for reconstructing the complex-valued refractive index distribution of weakly scattering objects. A reconstruction theory of intensity DT (I-DT) has been proposed [Gbur and Wolf, JOSA A, 2002] that can accomplish such a reconstruction from knowledge of only the wavefield intensities on two different transverse planes at each tomographic view angle. In this work, we elucidate the relationship between I-DT and phase-contrast tomography and demonstrate that I-DT reconstruction theory contains some of the existing reconstruction algorithms for phase-contrast tomography as special cases.
    Diffraction tomography
    Tomographic reconstruction
    Intensity
    Citations (16)
    In clinical x-ray phase imaging, the significant tissue attenuation cannot be ignored. In x-ray phase tomography, the presence of tissue attenuation requires acquisition of at least two images for the retrieval of tissue phase for a given tomographic view. This paper presents an important observation that the same map of the projected electron densities can determine both the phase and attenuation maps of soft tissues, provided that the dominance of incoherent scattering holds. Based on this observation a new strategy to perform the phase retrieval was developed. A 3-D phase tomography reconstruction formula was derived, which combines the three-dimensional inverse Radon transform with the phase retrievals for soft tissues. This new formula alleviates all the technical difficulties associated with the requirement of acquiring two images per tomographic view for phase-retrievals in x-ray phase tomography.
    Citations (11)
    We develop an analytical model for three dimensional phase contrast tomography for a pure phase object. The model incorporates an extended source, which is suitable for a laboratory based microfocus x-ray source. From the modeled intensities for the tomographic data set we obtain a model reconstruction and define a reconstruction quality factor that allows us to optimize the tomographic reconstruction for given feature sizes in an object.
    Tomographic reconstruction
    Feature (linguistics)
    Citations (4)
    This chapter contains sections titled: Introduction Fundamentals of Phase-Space Tomography Phase-Space Tomography of Beams Separable in Cartesian Coordinates Radon Transform Example: Tomographic Reconstruction of the WD of Gaussian Beams Experimental Setup for the Measurements of the WD Projections Reconstruction of WD: Numerical and Experimental Results Practical Work for Postgraduate Students Conclusions Acknowledgments References
    Tomographic reconstruction
    Radon transform
    Tomography is defined as an image reconstruction technique that exploits different points of view, and different observation points. Generally, tomographic images can be constructed by illuminating the target with a microwave signals and measuring the energy that passes through the target e.g. transmission tomography, or reflected from the target as in reflection tomography. Reflection tomography is used in some cases when the transmission tomography cannot be accomplished due to physical limitations, or high attenuation losses due to high material impedance. In this paper, we investigate the impact of surfaces placed beside the transmitter and/or the receiver, and quantify these effects via image analysis at high frequency domain. Our goal in this paper is to reduce the effect of side-lobes that may appear as result of these surfaces. We reduce the reflected waves from the surfaces by designing the surfaces using specific materials or by changing the placement of both the transmitter and/or receiver antenna. Moreover, the resulting tomographic image will be processed using the Winner filter to remove any remaining noise.
    Tomographic reconstruction
    Reflection
    Microwave Imaging
    Nowadays, X-ray tomography is one of the most pertinent directions of the development of non-destructive testing methods. Besides the experimental setup to conduct the X-ray tomographic measurements, it is necessary to have stable and flexible software. In most cases, existing software packages for the reconstruction of tomographic data are not freeware. This makes tomographic experiments not flexible because of the restriction of the source code correction. This papers explains how to implement one of important parts of tomographic research, namely, experimental data simulation, which allows to test reconstruction algorithms further.
    Tomographic reconstruction
    Industrial computed tomography
    Radon transform
    Code (set theory)