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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An evaluation of computerised tomography (CT) based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four field breast technique

Govender, Yoguvathie January 2007 (has links)
Submitted in fulfillment of Masters in Radiography, Durban University of Technology, Durban, 2007. / Aim/research questions The aim of the study was to evaluate CT-based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four-field breast technique, in terms of the depth of supraclavicular and axillary nodes, the variability of the breast tissue and the dose inhomogeneity at the matchline. The variability of the depth of supraclavicular and axillary nodes has not been documented in any local or national studies. When simulating patients for treatment, it is evident that the anatomical variability of patient chest wall thickness, shape and size is a contributing factor towards the final treatment plan and dose distribution achieved. Therefore knowing the correct depth of the nodes and being able to clearly demarcate the breast tissue should result in a favourable dose administration. The following questions were addressed:  What is the dose to the supraclavicular nodes from both plans?  What is the dose to the axillary nodes from both plans?  How do the plans differ in terms of dose coverage to the supraclavicular and axillary nodes?  What is the relationship between the depth of the supraclavicular nodes and the patient separation? ii  What is the relationship between the depth of the axillary nodes and the patient separation?  Does the target volume receive adequate dose coverage from the plans?  How is dose to the heart volume affected by target coverage on both plans?  How is dose to the lung volume affected by target coverage on both plans?  What is the dose variability along the matchline?  Are the plans over dosing?  Are the plans under dosing? / M
2

Tomographic reconstruction and denoising. / 斷層攝影的重建及降噪 / Duan ceng she ying de chong jian ji jiang zao

January 2011 (has links)
Ma, Ka Lim. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves [110]-117). / Abstracts in English and Chinese. / Chapter 1 --- Radon Transform and Medical Tomography --- p.1 / Chapter 1.1 --- Computed Tomography --- p.2 / Chapter 1.2 --- Emission Computed Tomography --- p.4 / Chapter 1.2.1 --- SPECT --- p.5 / Chapter 1.2.2 --- PET --- p.6 / Chapter 1.3 --- Radon Transform --- p.8 / Chapter 1.3.1 --- Properties of Radon Transform --- p.10 / Chapter 1.3.2 --- Fourier Slice Theorem --- p.11 / Chapter 1.4 --- Research Objective --- p.12 / Chapter 2 --- Popular Tomographic Reconstruction Algorithms --- p.14 / Chapter 2.1 --- Analytic Method --- p.15 / Chapter 2.1.1 --- Direct Fourier Method (DFM) --- p.15 / Chapter 2.1.2 --- Backprojection (BP) --- p.17 / Chapter 2.1.3 --- Backprojection Filtering (BPF) --- p.19 / Chapter 2.1.4 --- Filtered Backprojection (FBP) --- p.21 / Chapter 2.2 --- Iterative Method --- p.23 / Chapter 2.2.1 --- Maximum Likelihood - Expectation Maximization (ML-EM) --- p.25 / Chapter 2.2.2 --- Ordered Subsets Expectation Maximization (OSEM) --- p.27 / Chapter 3 --- Consistent Reconstruction --- p.30 / Chapter 3.1 --- Directional Filter Bank (DFB) --- p.30 / Chapter 3.1.1 --- Interpolation in horizontal function space --- p.32 / Chapter 3.1.2 --- Directional Multiresolution Analysis --- p.33 / Chapter 3.1.3 --- Iterated Filter Bank Equivalence --- p.36 / Chapter 3.1.4 --- Vertical Directional Function Space --- p.38 / Chapter 3.1.5 --- Summary --- p.40 / Chapter 3.2 --- Reconstruction Scheme --- p.42 / Chapter 3.2.1 --- Choices for basis function 6m --- p.43 / Chapter 3.2.2 --- Choices for coordinate mapping function wm --- p.46 / Chapter 3.2.3 --- Summary --- p.49 / Chapter 3.3 --- Experiment --- p.49 / Chapter 3.3.1 --- Experiment for consistent reconstruction with different choices --- p.50 / Chapter 3.3.2 --- Experiment for comparison with different reconstruction methods --- p.54 / Chapter 3.4 --- Conclusion --- p.56 / Chapter 4 --- Tomographic Denoising --- p.57 / Chapter 4.1 --- SURE-LET and PURE-LET denoising --- p.59 / Chapter 4.1.1 --- SURE-LET --- p.60 / Chapter 4.1.2 --- PURE-LET --- p.62 / Chapter 4.2 --- Experiment --- p.64 / Chapter 4.2.1 --- Experiment on SURE-LET Denoising --- p.65 / Chapter 4.2.2 --- Experiment on PURE-LET Denoising --- p.69 / Chapter 4.2.3 --- Conclusion --- p.76 / Chapter 5 --- Sinogram Retrieval --- p.77 / Chapter 5.1 --- Sinogram Retrieval Method --- p.78 / Chapter 5.1.1 --- MATLAB Radon Function --- p.79 / Chapter 5.1.2 --- Subordinate Gradient (SG) Algorithm --- p.81 / Chapter 5.1.3 --- Orthonormal Subordinate Gradient (OSG) Algorithm --- p.81 / Chapter 5.2 --- Experiment --- p.84 / Chapter 5.2.1 --- Limitation of Sinogram Retrieval --- p.84 / Chapter 5.2.2 --- Comparison of Sinogram Retrieval Algorithms --- p.86 / Chapter 5.2.3 --- Embedded in Tomographic Reconstruction --- p.88 / Chapter 5.2.4 --- Embedded in Tomographic Denoising --- p.90 / Chapter 5.3 --- Conclusion --- p.96 / Chapter 6 --- Conclusion --- p.97 / Chapter 6.1 --- Summary --- p.97 / Chapter 6.1.1 --- Tomographic Reconstruction --- p.97 / Chapter 6.1.2 --- Tomographic Denoising --- p.98 / Chapter 6.1.3 --- Sinogram Retrieval --- p.98 / Chapter 6.2 --- Future Research --- p.99 / Chapter 6.2.1 --- Tomographic Reconstruction --- p.99 / Chapter 6.2.2 --- Tomographic Denoising --- p.99 / Chapter 6.2.3 --- Sinogram Retrieval --- p.99 / Chapter A --- Examples of Radon Transform --- p.100 / Chapter B --- Experimental Phantom Image --- p.104 / Chapter C --- Results of sinogram retrieval experiments --- p.107 / Bibliography --- p.110
3

An evaluation of computerised tomography (CT) based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four field breast technique

Govender, Yoguvathie January 2007 (has links)
Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2007 xxiv, 142 leaves, Annexures A-L / The aim of the study was to evaluate CT-based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four-field breast technique, in terms of the depth of supraclavicular and axillary nodes, the variability of the breast tissue and the dose inhomogeneity at the matchline.
4

Can cross sectional imaging contribute to the investigation of unexplained child deaths? A literature review

Beck, Jamie J.W. January 2014 (has links)
This review examines the factors that can influence an investigation into the unexpected death of a child before considering if using imaging techniques could be of benefit. Method A systematic search strategy was adopted to search databases using keywords, these results were then subjected to inclusion and exclusion criteria to filter and refine the evidence base further. Discussion More research is published on the use of MRI in comparison with other modalities. There is evidence in the case of MRI in particular that its use could be of benefit in identifying and ruling out potential causes of death in children. Conclusion More research is needed on the use of CT but the routine use of MRI in child death investigation could now be considered. Ethical considerations appear to be a barrier to research in this area and discussions as to how such considerations can be overcome is necessary.

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