Pharmacodynamics Of Monoamine Transporter Releasing Agents And Reuptake Inhibitors, Alexa Holloway

Theses and Dissertations

Ligands of the human monoamine transporters encompass a wide range of both illicit and therapeutic drugs that act upon neural circuitry related to reward, motivation, and the processing of salient stimuli. The present study utilizes two methods for analyzing transporter substrates and inhibitors in order to characterize activity and assess potency. The first measures transient changes in intracellular calcium as a surrogate for transporter activity by harnessing the electrical coupling of monoamine transporters and L-type calcium channels. This is used to analyze novel chimera of the strong hDAT inhibitors methylphenidate and ��-PPP in order to assess the contribution of specific …

Development And Implementation Of A Homogeneous And A Heterogeneous Anthropomorphic End To End Quality Assurance Audit System Phantom For Magnetic Resonance Guided Radiotherapy Modalities Ranging From 0.35 T To 1.50 T, Angela Steinmann

Dissertations and Theses (Open Access)

Introduction: Magnetic resonance (MR) guided radiation therapy (MRgRT) is an emerging field that integrates an MR imager with either a linear accelerator or three radioactive cobalt-60 sources. Before institutions participate in multi-institutional NCI-sponsored clinical trials, they are required to perform a credentialing test provided by IROC-Houston. During the credentialing test, end-to-end phantoms are used to evaluate the institution’s ability to perform consistent and accurate radiation treatments. IROC-Houston’s conventional anthropomorphic phantoms are not visible in MR, thus they are insufficient for MRgRT systems. The purpose of this work was to create an anthropomorphic thorax and a head and neck (H&N) phantom …

Development Of 3d-Printed Patient Specific Bolus For Clinical Use In To Tal Scalp Irradiation, Garrett Baltz

Dissertations and Theses (Open Access)

Total scalp irradiation (TSI) is a specialized radiation therapy technique that aims to deliver a uniform dose to the entire scalp. Original electron-based TSI techniques had limited homogeneity due to hot and cold spots created at field junctions due to the multiple matched fields that were required to treat the entire scalp. The transition to photon volumetric-modulated arc therapy based TSI techniques has improved homogeneity, to the point where non-conformal bolus is now a limiting factor. Bolus is required to build-up full dose to the scalp surface in total scalp irradiation. Creating bolus that is conformal to the scalp is …

Plasma Medicine: A Brief Introduction, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years. Today, research is being conducted on a number of applications including wound healing and cancer treatment. Although a lot of knowledge has been created and our understanding of the fundamental mechanisms that play important roles in the interaction between low temperature plasma and …

Evaluation And Adaptation Of Live-Cell Interferometry For Applications In Basic, Translational, And Clinical Research, Kevin A. Leslie

Theses and Dissertations

Cell mass is an important indicator of cell health and status. A diverse set of techniques have been developed to precisely measure the masses of single cells, with varying degrees of technical complexity and throughput. Here, the development of a non-invasive, label-free optical technique, termed Live-Cell Interferometry (LCI), is described. Several applications are presented, including an evaluation of LCI’s utility for assessing drug response heterogeneity in patient-derived melanoma lines and the measurement of CD3+ T cell kinetics during hematopoietic stem cell transplantation. The characterization of mast cells during degranulation, the measurement of viral reactivation kinetics in Kaposi’s Sarcoma, and drug …

Volumetric, Magnetic Resonance-Visible, And Radiation-Sensitive Detectors For Magnetic Resonance Image-Guided Radiation Therapy, Hannah J. Lee

Dissertations and Theses (Open Access)

VOLUMETRIC, MAGNETIC RESONANCE-VISIBLE, AND RADIATION-SENSITIVE DETECTORS FOR MAGNETIC RESONANCE IMAGE-GUIDED RADIATION THERAPY

Hannah Jungeun Lee

Advisory Professor: Geoffrey S. Ibbott, Ph.D.

Due to the superior soft-tissue contrast of magnetic resonance imaging (MRI) compared to conventional computed tomography (CT) and other on-board imaging techniques, several groups have integrated MRI and radiation treatment machine systems. The advent of MR image-guided radiation therapy (MR-IGRT) using systems, such as the 1.5 MRI – 7 MV linear accelerator (MR-Linac), now allow for improved soft-tissue on-board imaging for patient position and tumor target localization verification and the ability to assess functional biological tissue characteristics with MRI, …

Numerically Solving A System Of Pdes Modeling Chronic Wounds Treated With Oxygen Therapy, Stefan Stryker

Mahurin Honors College Capstone Experience/Thesis Projects

Chronic wounds such as diabetic foot ulcers are the leading cause of non-traumatic amputations in developed countries. For researchers to better understand the physiology of these wounds, a mathematical model describing oxygen levels at the wound site can be used to help predict healing responses. The model utilizes equations that are modified from work by Guffey (2015) that consists of four variables – oxygen, bacteria, neutrophils, and chemoattractant within a system of partial differential equations. Our research focuses on numerically solving these partial differential equations using a finite volume approach. This numerical solver will be important for future research in …

High Performance Computation Of Cardiac Models In Real-Time Using Webgl, Abouzar Kaboudian, Flavio H. Fenton

Biology and Medicine Through Mathematics Conference

No abstract provided.

Low Energy Defibrillation By Synchronization; 90 % Less Energy Compared To One Shock., Flavio H. Fenton, Yanyan Ji, Ilija Uzelac, Niels Otani, Elizabeth M. Cherry

Biology and Medicine Through Mathematics Conference

No abstract provided.

Strategies Of Balancing: Regulation Of Posture As A Complex Phenomenon, Allison Leich Hilbun

Electronic Theses and Dissertations

The complexity of the interface between the muscular system and the nervous system is still elusive. We investigated how the neuromuscular system functions and how it is influenced by various perturbations. Postural stability was selected as the model system, because this system provides complex output, which could indicate underlying mechanisms and feedback loops of the neuromuscular system. We hypothesized that aging, physical pain, and mental and physical perturbations affect balancing strategy, and based on these observations, we constructed a model that simulates many aspects of the neuromuscular system. Our results show that aging changes the control strategy of balancing from …

Improving Attenuation Correction In Hybrid Positron Emission To Mography, Hua Asher Ai

Dissertations and Theses (Open Access)

Hybrid positron emission tomography imaging techniques such as PET/CT and PET/MR have undergone significant developments over the last two decades and have played increasingly more important roles both in research and in the clinic. A unique advantage PET has over other clinical imaging modalities is its capability of accurate quantification. However, as the most critical component of PET quantification, attenuation correction in hybrid PET systems is challenged in several different aspects, including the spatial- temporal mismatch between the PET emission images and the associated attenuation images provided by the complementary modality, and the difficulty in bone identification in the MR-based …

Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed To Mography, Jessica L. Nute

Dissertations and Theses (Open Access)

Calcific and hemorrhagic foci of susceptibility are frequently encountered on routine brain MR studies. Both etiologies cause variations in local magnetic field strength, leading to dark regions on 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 subsequent intracranial bleeding; as such, identification of hemorrhage is vital in preventing the inappropriate use of anticoagulant medications in patients with hemorrhagic lesions.

Given there currently …

Development Of A New Independent Monte Carlo Dose Calculation Quality Assurance Audit To Ol For Clinical Trials, Austin M. Faught

Dissertations and Theses (Open Access)

Introduction: Commercially available treatment planning systems (TPS) may use a number of different radiation dose calculation algorithms during the planning process. The Radiological Physics Center (RPC), tasked with ensuring clinically comparable and consistent dose delivery amongst institutions participating in NCI funded multi-institutional clinical trials, has traditionally relied upon measurements to achieve this objective. As a supplement to the tools used by the RPC, an independent dose calculation tool is needed to determine patient dose distributions in three dimensions so as to act as a quality assurance tool for the dose calculations.

Methods: Multiple source models representing the output of Elekta …

Evaluation Of Artifacts In Experimental Cine 4d Ct Acquisition Methods, Sarah Joy

Dissertations and Theses (Open Access)

Four-dimensional computed tomography (4D CT) has increased the accuracy of radiation treatment planning for patients in whom the extent of target motion is large. 4D CT has become a standard of care for radiation treatment simulation, allowing decreased motion artifacts and increased spatiotemporal localization of anatomical structures that move. However, motion artifacts may still remain. These artifacts, or artificial anatomic spatial distributions, add a systematic uncertainty to the treatment process and limit the accuracy of lung function images derived from CT. We proposed to reduce the motion artifacts in cine 4D CT by using three novel investigational 4D CT acquisition …

A Nonrigid Registration Method For Correcting Brain Deformation Induced By Tumor Resection, Yixun Liu, Chengjun Yao, Fotis Drakopoulos, Jinsong Wu, Liangfu Zhou, Nikos Chrisochoides

Computer Science Faculty Publications

Purpose: This paper presents a nonrigid registration method to align preoperative MRI with intraoperative MRI to compensate for brain deformation during tumor resection. This method extends traditional point-based nonrigid registration in two aspects: (1) allow the input data to be incomplete and (2) simulate the underlying deformation with a heterogeneous biomechanical model.

Methods: The method formulates the registration as a three-variable (point correspondence, deformation field, and resection region) functional minimization problem, in which point correspondence is represented by a fuzzy assign matrix; Deformation field is represented by a piecewise linear function regularized by the strain energy of a heterogeneous biomechanical …

Scanned Ion Beam Therapy For Thoracic Tumors, John Gordon Eley

Dissertations and Theses (Open Access)

Although frequently cured of Hodgkin lymphoma, adolescents and young adults can develop radiation induced second cancers. These patients could potentially benefit from scanned ion radiotherapy yet likely would require motion mitigation strategies. In theory, four-dimensional (4D) optimization of ion beam fields for individual motion states of respiration can enable superior sparing of healthy tissue near moving targets, compared to other motion mitigation strategies. Furthermore, carbon-ion therapy can sometimes provide greater relative biological effectiveness (RBE) for cell sterilization in a target but nearly equivalent RBE in tissue upstream of the target, compared to proton therapy. Thus, we expected that for some …

Development And Implementation Of Acoustic Feedback Control For Scanning Probe Microscopy, Rodolfo Fernandez Rodriguez

Dissertations and Theses

A remote-sensing acoustic method for implementing position control feedback in Scanning Probe Microscopy (SPM) is presented. The capabilities of this feedback control using the new Whispering Gallery Acoustic Sensing (WGAS) method is demonstrated in a Shear-force Scanning Probe Microscope that uses a sharp probe attached to a piezoelectric Quartz Tuning Fork (QTF) firmly mounted on the microscope's frame. As the QTF is electrically driven its mechanical response reaches the SPM frame which then acts as a resonant cavity producing acoustic modes measured with an acoustic sensor strategically placed on the SPM head. The novelty of the WGAS resides in using …

Utilizing Induced Voxel Correlation In Fmri Analysis, Daniel B. Rowe, Andrew S. Nencka

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

Risk Of Second Malignant Neoplasms Following Proton Arc Therapy And Volumetric Modulated Arc Therapy For Prostate Cancer, Laura A. Rechner

Dissertations and Theses (Open Access)

The risk of second malignant neoplasms (SMNs) following prostate radiotherapy is a concern due to the large population of survivors and decreasing age at diagnosis. It is known that parallel-opposed beam proton therapy carries a lower risk than photon IMRT. However, a comparison of SMN risk following proton and photon arc therapies has not previously been reported. The purpose of this study was to predict the ratio of excess relative risk (RRR) of SMN incidence following proton arc therapy to that after volumetric modulated arc therapy (VMAT). Additionally, we investigated the impact of margin size and the effect …

New To Ols For Monitoring Gamma Camera Uniformity, Brad K. Lofton

Dissertations and Theses (Open Access)

Detector uniformity is a fundamental performance characteristic of all modern gamma camera systems, and ensuring a stable, uniform detector response is critical for maintaining clinical images that are free of artifact. For these reasons, the assessment of detector uniformity is one of the most common activities associated with a successful clinical quality assurance program in gamma camera imaging. The evaluation of this parameter, however, is often unclear because it is highly dependent upon acquisition conditions, reviewer expertise, and the application of somewhat arbitrary limits that do not characterize the spatial location of the non-uniformities. Furthermore, as the goal of any …

Thoracic Radiotherapy Treatment Planning With Cine Pet/Ct, Adam C. Riegel

Dissertations and Theses (Open Access)

Purpose: Respiratory motion causes substantial uncertainty in radiotherapy treatment planning. Four-dimensional computed tomography (4D-CT) is a useful tool to image tumor motion during normal respiration. Treatment margins can be reduced by targeting the motion path of the tumor. The expense and complexity of 4D-CT, however, may be cost-prohibitive at some facilities. We developed an image processing technique to produce images from cine CT that contain significant motion information without 4D-CT. The purpose of this work was to compare cine CT and 4D-CT for the purposes of target delineation and dose calculation, and to explore the role of PET in target …

Radiotherapy Optimal Design: An Academic Radiotherapy Treatment Design System, R Acosta, W Brick, A Hanna, Allen Holder, D Lara, G Mcquillen, D Nevin, P Uhlig, B Salter

Mathematical Sciences Technical Reports (MSTR)

Optimally designing radiotherapy and radiosurgery treatments to increase the likelihood of a successful recovery from cancer is an important application of operations research. Researchers have been hindered by the lack of academic software that supports head-to-head comparisons of different techniques, and this article addresses the inherent difficulties of designing and implementing an academic treatment planning system. In particular, this article details the algorithms and the software design of Radiotherapy optimAl Design (RAD).