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Full-Text Articles in Physical Sciences and Mathematics
Stereotactic Localization And Targeting Accuracy For Experimental Proton Radiosurgery, Yin Chen
Stereotactic Localization And Targeting Accuracy For Experimental Proton Radiosurgery, Yin Chen
Theses Digitization Project
The purpose of this study was to improve an existing experimental proton radiosurgery system at Loma Linda University Medical Center to reach sub-millimeter accuracy before proton radiosurgery with narrow beams can be used in a clinical trial. Protons, different from photons (i.e., x-rays or gamma rays), are charged with particles that slow down in matter and release a burst of energy near the end of their range (maximum depth of penetration), which is called the Bragg peak, named after the physicist William Henry Bragg who discovered it in 1903. Photon beams deliver most doses over a large area near the …
Alternative Hull Detection Techniques For Preprocessing In Proton Computed Tomography Reconstruction, Blake Edward Schultze
Alternative Hull Detection Techniques For Preprocessing In Proton Computed Tomography Reconstruction, Blake Edward Schultze
Theses Digitization Project
The purpose of this study was to develop computationally efficient hull detection techniques appropriate for image reconstruction using sparse matrices. The hull detection techniques investigated were space carving (SC), modified space carving (MSC), and space modeling (SM) and these were compared to the cone-beam version of filtered back projection (FBP) algorithm in terms of their computation time and the quality of the object hull they produced.
Fiducial-Free Alignment Verification Techniques For Intracranial Radiosurgery, Kenneth Matthew Williams
Fiducial-Free Alignment Verification Techniques For Intracranial Radiosurgery, Kenneth Matthew Williams
Theses Digitization Project
This thesis serves as the basis for a method using image registration to automate patient alignment in an effort to eliminate the dependency on the fiducial markers as well as improve the accuracy efficiency of the alignment process. Proton beams are an external beam modality of radiation therapy that can be used effectively for radiosurgical applications due to the dosimetry advantage of the Bragg peak. The Bragg peak is a phenomenon exploited by proton beam therapy to concentrate the effect of the beams on the tumor while minimizing damage to critical structures and other health tissues within the patient.
Impact Of Varied Low Resolution Phantoms On Intensity Modulated Proton Therapy Dose Distributions, Aarohi Shyam Padhye
Impact Of Varied Low Resolution Phantoms On Intensity Modulated Proton Therapy Dose Distributions, Aarohi Shyam Padhye
Theses Digitization Project
The primary purpose of this thesis is to discuss the usefulness of image segmentation techniques in creating accurate proton dose distribution plans. The calculation of the proton dose distribution has to take into account the material (tissue, bone, brain) in the treatment area of the patients body.
Reordered Subsets Reconstruction Of Proton Computed Tomography, Wenzhe Xue
Reordered Subsets Reconstruction Of Proton Computed Tomography, Wenzhe Xue
Theses Digitization Project
This project investigates the improvement of iterative reconstruction using reordered subsets. Block iterative projection and Ordered Subset reconstruction algorithms are developed to improve the performance of image reconstruction. Contains source code.
Optimized And Integrated Alignment System For Functional Proton Radiosurgery, Fadi Easa Shihadeh
Optimized And Integrated Alignment System For Functional Proton Radiosurgery, Fadi Easa Shihadeh
Theses Digitization Project
In this thesis work, a system for proton beam alignment was studied and optimized in many of its functional areas. The resulting system was named Positioning Alignment Control System (PACS). The PACS system is an integrated and efficient system as a result of the work done on it in the course of this thesis work.
Software-Based Gradient Nonlinearity Distortion Correction, Thomas Seward Lee
Software-Based Gradient Nonlinearity Distortion Correction, Thomas Seward Lee
Theses Digitization Project
The primary purpose of the thesis is to discuss the use of Magnetic Resonance Imaging (MRI) in functional proton radiosurgery. The methods presented in this thesis were specifically designed to correct gradient nonlinearity distortion, the single greatest hurdle that limits the deployment of MRI-based functional proton radiosurgery systems. The new system central in the thesis fully utilized MRI to provide localization of anatomical targets with submillimeter accuracy. The thesis provides analysis and solutions to the problems related to gradient nonlinearity distortion. The characteristics of proton radiosurgery are introduced, in addition to a discussion of its advantages over other current methods …
Optimization Of A Sequential Alignment Verification And Positioning System (Savps) For Proton Radiosurgery, Mahesh Raj Neupane
Optimization Of A Sequential Alignment Verification And Positioning System (Savps) For Proton Radiosurgery, Mahesh Raj Neupane
Theses Digitization Project
Functional proton-beam stereotactic radiosurgery requires sub-millimeter alignment accuracy. A patient tracking system called Sequential Alignment and Position Verification System (SAVPS) is under development at Loma Linda University Medical Center. An optical positioning system (OPS), manufactured by Vicon Peak, has been chosen to verify the correct alignment of the target with the proton beam axis. The main objective of this thesis is to optimize an existing version of SAVPS by conducting error analysis. An image processing algorithm was developed and applied to estimate the error introduced by the Patient Positioning System (PPS) in order to derive the true error of the …