Medicine and Health Sciences Commons^™

Studies Of Forward Projection Algorithms And Implementation On Pc And Fpga, Minsung Cho

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis first aims to understand how a part of the computed tomography (CT) algorithm called “forward projector” (FP) works and how it can be accelerated at a hardware level. Two methods of FP are defined and studied: pixel-driven and ray-driven. Both methods fundamentally use the property of line integral and Bresenham’s algorithm. As the result of the study of the two FP methods, the ray-driven algorithm implemented in C++ performed 35% faster than the pixe-driven algorithm implemented in Python.This thesis implements the ray-driven forward projector algorithm using field-programmable gate array (FPGA), making use of hardware-acceleration techniques. The result shows …

Monte Carlo Simulation Of Thallium-Bromide Semiconductor Detector For Range Verification Of A Carbon Ion Radiotherapy Beam Through Prompt Gamma-Ray Detection, Peter Dimpfl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thallium-Bromide is a semiconductor material which is well suited for photon detection. Composed of high atomic number elements and a high mass density of 7.56 g/cm3, TlBr has superb photon stopping power. External beam radiation therapy is an ever-changing environment with technology rapidly improving. With proton therapy facilities becoming more widely available, and carbon ion facilities showcasing the benefits of carbon ion radiation therapy, there is an industry need toprovide accurate dosimetric treatment plans to verify patients are receiving proper care. Current clinical practices apply safety margins to clinical target volumes to safe treatment. Through research to improve detection techniques, …

Turning Up The Sound! Senior-Level Sonographers' Perspectives On The Workforce Readiness/Competency Of Entry-Level Sonographers In The Workplace, Janice L. Glasper

UNLV Theses, Dissertations, Professional Papers, and Capstones

There has been a longstanding preoccupation with the workforce readiness and competency of our nation’s graduates since the release of the National Commission on Excellence in Education’s, April 1983 landmark report, A Nation at Risk: “The Imperative for Educational Reform”, which indicated that the educational foundations of our society were being eroded by a rising tide of mediocrity that threatened our very future as a Nation and a people. Now, more than 35 years since the release of A Nation at Risk, it appears that little has changed. Extensive research continues to report that graduates of post-secondary institutions are unprepared …

Safety Of Endoscopic Retrograde Cholangiopancreatography (Ercp) In Pregnancy: A Systematic Review And Meta-Analysis, Mohamed Azab, Shishira Bharadwaj, Mahendran Jayaraj, Annie S. Hong, Pejman Solaimani, Mohamad Mubder, Hyeyoung Yeom, Ji Won Yoo, Michael L. Volk

School of Medicine Faculty Publications

Background/Aims: Endoscopic retrograde cholangiopancreatography (ERCP) is a technically challenging procedure rarely associated with severe postprocedure complications. Hormonal changes during pregnancy promote cholelithiasis, but there are limited clinical data available on the outcomes of ERCP in pregnant women. ERCP techniques without irradiation were recently introduced as potential alternative. We performed a systematic review and meta-analysis to assess the safety of ERCP in pregnancy and to compare outcomes of radiation versus nonradiation ERCP. Materials and Methods: A systematic search of PubMed, Medline/Ovid, Web of Science, and Google Scholar through April 18th, 2018 using PRISMA and MOOSE guidelines identified 27 studies reporting the …

Creating A Dynamic, Multi-Purpose Correction For Multiple Geometries And Field Sizes To Account For Off-Axis And Asymmetric Backscatter With Varian Portal Dosimetry, Remy Manigold

UNLV Theses, Dissertations, Professional Papers, and Capstones

Intensity modulated radiation therapy and volumetric modulated arc therapy are increasingly common in radiation therapy due to their benefits of target conformity and normal tissue sparing. Due to the complexities of plan delivery and the precision required, the dose delivered must be accurately measured for quality assurance (QA). One of the most efficient ways to perform patient-specific QA when using clinical linear accelerators (linac) is to use an electronic portal imaging device (EPID). Amorphous silicon (aSi) Electronic Portal Imaging Devices (EPIDs) are attached to the linac and can provide real-time feedback with spatial resolution on the order of sub-millimeter pixel …

A Study On Automated Process For Extracting White Blood Cellular Data From Microscopic Digital Injured Skeletal Muscle Images, Bibek Karki

UNLV Theses, Dissertations, Professional Papers, and Capstones

Skeletal muscle injury is one of the common injuries caused by high-intensity sports activities, military related works, and natural disasters. In order to discover better therapies, it is important to study muscle regeneration process. Muscle regeneration process tracking is the act of monitoring injured tissue section over time, noting white blood cell behavior and cell-fiber relations. A large number of microscopic images are taken for tracking muscle regeneration process over multiple time instances. Currently, manual approach is widely used to analyze a microscopic image of muscle cross section, which is time consuming, tedious and buggy.

Automation of this research methodology …

Sex Determination Using Discriminant Function Analysis In Hispanic Children And Adolescents: A Lateral Cephalometric Study, Alyssa E. Sprowl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lateral cephalometric radiographs have been used for years to help diagnose skeletal and dental patterns in Orthodontics. Within the last decade, these radiographs have caught the interest of the department of Anthropology for the identification of gender within the adult and adolescent population. Numerous publications have been made but failed to identify sexual dimorphism in the pre-adolescent population. 303 lateral cephalograms of pre and post Latino adolescence age ranging from 6.5 to 17.9 years old were obtained from University of Nevada, Las Vegas (UNLV) digital database. 25 variables were identified and plotted with all linear and angular measurements transferred into …

A Diffusion Tensor Imaging Software Comparison And Between Control Subjects And Subjects With Known Anatomical Diagnosis, Michael C. Moore

UNLV Theses, Dissertations, Professional Papers, and Capstones

Diffusion weighted imaging (DWI) is a magnetic resonance imaging (MRI) method that produces in vivo images of biological tissues weighted with the local micro-structural characteristics of water diffusion. Diffusion tensor imaging (DTI), a form of DWI, is useful when a tissue, such as the neural axons of white matter in the brain, has an internal fibrous structure that allows water to diffuse more rapidly in alignment with the fibers. Changes in the water diffusion pattern indicate changes in the fiber structure which can result from damage to the fibers. Measurements of the water diffusion patterns include overall diffusivity, Apparent Diffusion …

Ultrasound Imaging Of Lumbar Multifidus Immediately Following Three Physical Therapy Techniques In Asymptomatic Individuals, Victoria Byers, Steven Lim, Kathryn Rice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Study Design

Randomized, blinded, cohort, within subjects design.

Background and Objective

The effects of different manual therapy (MT) techniques on lumbar multifidus (LM) thickness have been investigated in subjects with low back pain (LBP) but have not been investigated in asymptomatic subjects. The objective of this study was to examine the immediate effects of mobilization and manipulation on contraction thickness of LM in healthy individuals.

Methods and Measures

Forty-two healthy individuals participated in the study. Ultrasound imaging techniques were used to record LM thickness (L4-5 level) at rest, during an abdominal drawing in maneuver (ADIM), and during a prone upper …

Using Thermoluminescent Dosimeters To Measure The Dose From High And Low Energy X-Ray Sources, Wesley Leon Boyd

UNLV Theses, Dissertations, Professional Papers, and Capstones

This work focused on using thermoluminescent dosimeters (TLDs) to measure the doses from two x-ray sources, a CT scanner and a linear accelerator (linac). In addition ion chambers were used to determine the isodose contours from the operation of the linac. 1mm x 1mm x 1mm TLD-100 microcubes were placed in a Lawrence Livermore National Laboratory (LLNL) torso phantom and irradiated using a Toshiba Aquilion One 320-Slice CT Scanner. Different thicknesses of shielding composed of antimony and bismuth powder suspended in an ethylene copolymer were used to shield the phantom and the dose reduction was measured. The dose reduction ranged …

Investigation Of Magnetic Resonance Imaging And Spectroscopy For The Detection Of Breast Cancer, Robert Thomas Etnire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Magnetic resonance imaging (MRI) of the breast offers an alternative to screening mammography which may benefit those women at high risk for breast cancer, women under the age of 40, and those with dense breast tissue. One concern with MRI is the number of high false positives. Coupling MRI with magnetic resonance spectroscopy(MRS) may lower the number of false positives, and thus improve the diagnostic capabilities of MRI for the clinician. MRS for breast imaging focuses on the total choline containing compounds in the spectra in the suspected breast lesion to analyze areas of concern. The results of the study …