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Perturbation approach to the time-resolved transmittance for a spatially varying scattering inclusion in a diffusive slab
No full textIn the framework of the perturbation approach to the diffusion equation, an analytical expression is derived to describe the effects on the time-resolved transmittance due to the presence of a spatially varying scattering inclusion hidden inside a diffusive slab. This formula assumes that the reduced scattering coefficient of the inclusion is spatially Gaussian distributed and complements that obtained for the absorptive case. The accuracy and the application range of the perturbed transmittance are investigated through comparisons with the numerical solutions of the time-dependent diffusion equation given by using the finite-element method. The proposed perturbation model is validated through a fitting procedure that determines the relative error in retrieving the scattering perturbation parameter of the inclusion located at the midplane of the slab. �� 2006 Optical Society of America
Edge response function measurements with different masks for image quality investigation in time-resolved laser transillumination
No full textOptical characterization of scattering media with absorbing ink by time-resolved transmittance
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Differences in membrane electric properties between C3H10T1/2 mouse embryo fibroblasts and their ionizing radiation and chemical transformed counterpa
No full textDose and image-quality evaluation in synchrotron radiation mammography
No full textMonochromatic X-ray beam produced by synchrotron radiation may be considered an ideal probe in some fields of diagnostic radiology. In this paper the potential of monochromatic synchrotron radiation X-ray beam in mammography is analyzed. The image quality of four different phantom radiographs, obtained using two different energies equal to 17 and 18 keV, respectively, and a mammographic film/screen system, is assessed. The doses have been determined for both energies by using thermoluminescent dosimeters and a 5-cm thick phantom having a composition of 50% water and 50% fat. The results have been compared with those obtained in the same manner using a mammographic unit equipped with a molybdenum anode, molybdenum filter tube and antiscanner grid. The radiographs obtained with synchrotron radiation show higher contrast and less blur than those obtained with a conventional mammographic system. The average breast doses, 1.55 and 0.80 mGy at 17 and 18 keV, respectively, are comparable with the dose (1.51 mGy) of the conventional techniqu
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