Browsing Masters Theses by Duke Department "Medical Physics"

Now showing items 21-40 of 50

Feasibility of Weighted Dual-Energy Subtraction Using Quasi-Monochromatic Beams for a Dedicated Mammotomography System

Polemi, Andrew Michael (2013)

The goal of this research was to investigate the feasibility of using a weighted dual-energy subtraction method in dedicated breast CT using quasi-monochromatic x-ray beams, to better distinguish soft tissues in the ...
Higher Order Tensor Diffusion Imaging of Complex White Matter Fiber Tracts

Murphy, Nicole E. (2012)

Resolving multiple fiber orientations within one imaging voxel is critical for accurate quantification of tissue microstructure and faithful reconstruction of the complex neural fiber pathways. It is recognized that the ...
Inter-Instituion Application of Knowledge-Based IMRT Treatment Planning

Good, David (2012)

Intensity Modulated Radiation Therapy (IMRT) has allowed a large degree of healthy tissue sparing while delivering therapeutic dose to tumors. However, the treatment planning process for IMRT is iterative and time ...
Investigation of Patient Positioning Accuracy in Lung Stereotactic Body Radiation Therapy

Turner, Kathryn (2013)

Purpose: It has been shown that patients' irregular breathing can cause variation in the delineation of the internal target volume (ITV) and affect the accuracy of four dimensional computed tomography (4DCT) and cone-beam ...
Knowledge-Based IMRT Treatment Planning for Bilateral Head and Neck Cancer

Schmidt, Matthew Charles (2013)

Intensity-modulated radiotherapy (IMRT) remains the standard of care for external beam radiation therapy for head and neck cancers. Planning for IMRT requires a trial-and-error approach that is completely dependent on ...
Knowledge-Based IMRT Treatment Planning for Prostate Cancer: Experience with 101 cases from Duke Clinic

Dick, Deon (2012)

Intensity-modulated radiotherapy (IMRT) has become an effective tool for cancer treatment with radiation. However, even expert radiation planners still need to spend a substantial amount of time, approximately 4 hours, ...
Knowledge Based Radiation Therapy with Three Dimensional Registration of the Planning Target Volume

Busselberg, Christopher Lorin (2012)

Knowledge based radiation therapy planning was developed as a way to use a knowledge base of clinically approved radiation therapy plans to shorten the amount of time necessary to create a new treatment plan. The method ...
MOSFET Sensitivity Variation With Integrated Dose History, Application of MOSFET in CT Dosimetry, Physics Characterization of Portal Monitor and Analysis of Portal Monitor Usage for Screening Contaminated People Based on Queueing Theory

Fredrickson, Mats (2011)

<bold>Purpose</bold>: (1) Evaluate use of portal monitor in a radiological emergency, (2) study the variation of MOSFET sensitivity with integrated dose history and (3) assess the accuracy of AAPM 96 formalism for ...
Multi-Slice Imaging Using a Time-Dependent Phase Constraint Through Hadamard Excitation with SENSE Reconstruction (M-PHENSE)

Hoberg, Jacob Ray (2012)

Image acquisition time is one of the most important considerations for magnetic resonance imaging (MRI). This is especially true for dynamic imaging (such as functional MRI or dynamic contrast enhanced MRI) which require ...
The Need for Adaptive Intensity Modulated Radiotherapy Replanning in Head-and-Neck Patients with Anatomical Changes During Treatment

Rhee, Dong Joo (2013)

AbstractPurpose: The aim of this study is to quantify the effectiveness of adaptive radiation therapy (ART) when anatomical changes to the tumor and/or the organs are observed for head and neck patients during ...
Neutron Dosimetry of Mice Using Monoenergetic Neutron Beams

Fallin, Brent Alan (2011)

In 2009 the researchers at Triangle Universities Nuclear Laboratory (TUNL) participated in a series of experiments with the Radiation Countermeasures Center of Research Excellence (RadCCORE). This thesis project is a ...
Neutron Stimulated Emission Computed Tomography: Optimization of Acquisition Parameters Using Resolution and Dosimetry in the Context of Liver and Breast Cancers

Raterman, Gretchen Mary (2013)

Proposed is a method for investigating optimal acquisition parameters in NSECT, neutron stimulated emission computed tomography, for good image quality and low dose for diagnosing liver and breast cancers. These ...
A Novel Comprehensive Verification Method for Multifocal RapidArc Radiosurgery Treatments

Niebanck, Michael Henry (2012)

<bold>Purpose:</bold> Radiosurgery has become a widely used procedure in the treatment of both solid tumors and secondary metastases in the brain. In cases with multiple brain lesions, isocenters are typically set up ...
On the Feasibility of a Novel In-Vivo Dosimeter for Brachytherapy

Vidovic, Adria Katarina (2013)

Purpose: Clinical brachytherapy systems are capable of delivering very high doses with high dose gradients. It is important therefore to be able to accurately verify the doses calculated by brachytherapy treatment ...
Optimization of RapidArc for Head-and-Neck Radiotherapy

Salazar, Jessica Emily (2011)

<bold>Purpose:</bold> The goal of this planning study is to determine which sectors of the gantry rotation are most and least important in the treatment of head-and-neck carcinomas with Intensity Modulated Arc Therapy, ...
Organ Localization: Moving Toward Patient Specific Prospective Organ Dosimetry for CT

Rybicki, Kevin (2012)

<bold>Purpose:</bold> Radiation doses from computed tomography (CT) examinations have come under public and governmental scrutiny because of several recent misadministrations of radiation across the country. Current ...
Plate-Specific Gain Map Correction for the Improvement of Detective Quantum Efficiency in Computed Radiography

Schnell, Erich A. (2010)

The purpose of this work is to improve the NPS, and thus DQE, of CR images by correcting for pixel-to-pixel gain variations specific to each plate. Ten high-exposure, open field images were taken with an RQA5 spectrum, ...
Practical Considerations with the Clinical Implementation of TG-18 Guidelines

Greene, Travis C. (2010)

Quality control of soft-copy displays is critical to ensure the proper contrast rendition of medical images. The American Association of Physicists in Medicine's (AAPM) Task Group 18 (TG-18) has developed a set of ...
Prostate Bed Motion During Post Prostatectomy Radiotherapy

Xu, Zhengzheng (2012)

Purpose: To report the inter-fractional prostate bed motion (PBM), and its correlation to the mean anterior rectal wall and mean posterior bladder wall shifts during post prostatectomy radiotherapy using cone-beam ...
Quantitative Magnetic Susceptibility of the Developing Mouse Brain

Argyridis, Ioannis (2012)

Cerebral development involves a complex cascade of events which are difficult to visualize in vivo. In this study we combine information from Diffusion Tensor Imaging (DTI) and Quantitative Susceptibility ...