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Full-Text Articles in Engineering
Design Of X-Ray Source For Real-Time Computed Tomography, Wesley William Tucker
Design Of X-Ray Source For Real-Time Computed Tomography, Wesley William Tucker
Doctoral Dissertations
"The reduction of motion blur in computed tomography (CT) drives the current research for multisource CT. Due to their compact nature, the current multisource systems utilize stationary angled anodes. Unfortunately, these configurations neither simplify the imaging geometry, nor satisfy the need for managing the high thermal loads demanded by real-time CT (30 acquisition frames per second). To add to the current field of knowledge, two x-ray tube concepts are presented in this dissertation. First, a simulation of transient thermal analysis was performed on a compact transmission-type x-ray tube anode operating in pulse-mode. A correlation was found between deposited beam power …
Iterative Ct Reconstruction From Few Projections For The Nondestructive Post Irradiation Examination Of Nuclear Fuel Assemblies, Muhammad Imran Khan Abir
Iterative Ct Reconstruction From Few Projections For The Nondestructive Post Irradiation Examination Of Nuclear Fuel Assemblies, Muhammad Imran Khan Abir
Doctoral Dissertations
The core components (e.g. fuel assemblies, spacer grids, control rods) of the nuclear reactors encounter harsh environment due to high temperature, physical stress, and a tremendous level of radiation. The integrity of these elements is crucial for safe operation of the nuclear power plants. The Post Irradiation Examination (PIE) can reveal information about the integrity of the elements during normal operations and off‐normal events. Computed tomography (CT) is a tool for evaluating the structural integrity of elements non-destructively. CT requires many projections to be acquired from different view angles after which a mathematical algorithm is adopted for reconstruction. Obtaining many …
An Investigation Of Markov Random Fields For Bayesian Reconstruction Of Single Photon Emission Computed Tomography, Lloyd Fredrick Arrowood
An Investigation Of Markov Random Fields For Bayesian Reconstruction Of Single Photon Emission Computed Tomography, Lloyd Fredrick Arrowood
Doctoral Dissertations
This research investigates the use of Markov random fields for Bayesian reconstruction algorithms to be used with high-resolution and high-sensitivity SPECT systems for small animal imaging. It extends previous research on mechanical models for Bayesian image reconstruction by using a three-dimensional nonconforming finite element model and linear elasticity concepts to derive minimum potential energy functionals which regularize the reconstruction process. It combines dual collimator SPECT projection data by using high-resolution data to penalize lower-resolution data. It compares the new three-dimensional penalized reconstruction technique with existing penalized techniques through the use of modulation transfer and contrast discrimination functions.