Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"dual-energy CT"”.
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Improving ion beam therapy treatment planning for metal implants by using dual-energy CT scanning
… of ion ranges in the patient’s tissue from CT images. The presence of non-tissue-equivalent mate- rials and materials with high photon attenuation like metals may aggravate this problem. Dual Energy Computed Tomography (DECT) allows to compute the electron density and effective atomic …
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Performance Evaluation of Material Decomposition Using Rapid Kvp-Switching Dual-Energy Ct For Assessing Bone Mineral Density
… trabecular bone, and has previously been characterized with dual-energy x-ray absorptiometry (DXA) or single-energy computed tomography (SECT). Dual-energy computed tomography (DECT) is able to create two three-dimensional sets of images representing the densities of two materials in a given …
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Evaluation and Clinical Implementation of a Dual-Energy CT Stopping-Power Ratio Mapping Technique for Proton-Therapy Treatment Planning
… at the end of the proton-beam range is correctly aligned to the edge of the clinical target volume (CTV). However, its clinical potential is dependent on the accurate localization of the Bragg-peak position from predicted stopping-power ratio maps. The method that is most commonly used in …
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Upscaling Lithology and Porosity Types from Microscopic to Core Domain with Thin Section Petrography, Dual Energy CT, and Rock Types: Creation of Diagenesis and Porosity Type Logs
… from the Microscope to the Core with Thin Section Petrography, Dual Energy CT, and Rock Types: Creation of Diagenesis and Porosity Type Logs Authors: Jacob M. Proctor, André W. Droxler, Naum Derzhi, Heath H. Hopson, Paul (Mitch) Harris, Pankaj Khanna, and Daniel J. Lehrmann ABSTRACT The …
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Functional and Molecular Imaging Using Nanoparticle Contrast Agents for Dual-Energy Computed Tomography
<p>X-ray computed tomography (CT) is one of the most useful diagnostic tools for clinicians, with widespread availability, fast scan times, and low cost. CT imaging can reveal a patient’s anatomy in exquisite detail and is extremely useful in the diagnosis of a wide variety of diseases. However, CT …
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Advanced Applications of Cardiac Computed Tomography for the Difficult-to-Image Patient
… the development of computed tomographic (CT) imaging the challenges of capturing the heart, with its perpetual, vigorous motion, and in particular the tiny detail within the coronary arteries, has driven technological progress. Today, CT is a widely used and rapidly growing modality for …
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Reduction of Dose Calculation Errors For Patients With Metal Implants Receiving Photon Radiation Therapy
… therapy have metal implants that can affect their treatment, and these metal implants can degrade the accuracy of dose calculations. Dose calculation errors result from limitations of modern dose calculation algorithms in modeling metal/tissue interface effects. Metals also cause streak …
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Advanced Statistical Modeling for Model-Based Iterative Reconstruction for Single-Energy and Dual-Energy X-Ray CT
Model-based iterative reconstruction (MBIR) has been increasingly broadly applied as an improvement over traditional, analytical image reconstruction methods in X-ray CT, primarily due to its significant advantage in drastic dose reduction without diagnostic loss. Early success of the method in …
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Characterization of Low Density Intracranial Lesions Using Dual-Energy Computed to mography
… the MR images that cannot be classified. Single-energy CT (SECT) can be used to identify lesions with attenuation over 100 HU as calcific, however lesions with lower attenuation cannot be reliably identified. While calcific lesions are unlikely to cause harm, hemorrhagic lesions carry a risk of …
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Improvements In Four-Dimensional and Dual Energy Computed to mography
<p>Dual energy and 4D computed tomography (CT) seek to address some of the limitations in traditional CT imaging. Dual energy CT, among other purposes, allows for the quantification and improved visualization of contrast materials, and 4D CT is often used in radiation therapy applications as it …
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Simulation studies on X-ray imaging of brain parenchyma and tumors
Computed Tomography (CT) is an imaging modality with many advantages but is lacking of the ability to image the tissues in the parenchyma of the brain and brain tumours in early stages. Aim of the presented research is to investigate whether CT could be used to image the soft tissue of the brain …
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Dual energy image reconstruction and systems for application in proton therapy treatment planning
… be known. This parameter is dependent on the electron density and effective atomic number of the material and describes the energy loss per unit length in the tissue. In current clinical practice, the SPR of patient tissues is obtained through single energy CT (SECT) scanning. The SECT scan …
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Robust Treatment Planning and Robustness Evaluation for Proton Therapy of Head and Neck Cancer
… approaches, which account for uncertainties directly into the plan optimization process, are able to generate high quality plans robust against uncertainties compared to a PTV margin expansion approach. During radiation treatment, patients are prone to present anatomical variations during the …
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Alternating Minimization Algorithms for Dual-Energy X-Ray CT Imaging and Information Optimization
… contributes toward solutions to two distinct problems linked through the use of common information optimization methods. The first problem is the X-ray computed tomography (CT) imaging problem and the second is the computation of Berger-Tung bounds</p><p>for the lossy distributed source …
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Dual Energy Computed to mography For Proton Therapy Treatment Planning
… is gaining popularity because of the unique characteristics of its dose distribution, e.g., high dose-gradient at the distal end of the percentage-depth-dose curve (known as the Bragg peak). The high dose-gradient offers the possibility of delivering high dose to the target while still sparing …
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Feasibility of Using Virtual Unenhanced Images to Replace Pre-Contrast Images In Multiphase Renal Ct Examinations
<p>Multiphase renal CT exams are a commonly used imaging technique for the diagnosis of renal masses. The pre-contrast, or true unenhanced (TUE), image provides a baseline for enhancement measurements which is an important criteria used to characterize renal lesions, consequently it is crucial that …