Other Medical Sciences Commons^™

Evaluation Of The Quantitative Accuracy Of A Commercially-Available Positron Emission Mammography Scanner, Adam Springer

Dissertations and Theses (Open Access)

Objective: The PEM Flex Solo II (Naviscan, Inc., San Diego, CA) is currently the only commercially-available positron emission mammography (PEM) scanner. This scanner does not apply corrections for count rate effects, attenuation or scatter during image reconstruction, potentially affecting the quantitative accuracy of images. This work measures the overall quantitative accuracy of the PEM Flex system, and determines the contributions of error due to count rate effects, attenuation and scatter.

Materials and Methods: Gelatin phantoms were designed to simulate breasts of different sizes (4 – 12 cm thick) with varying uniform background activity concentration (0.007 – 0.5 μCi/cc), cysts and …

Thoracic Target Volume Delineation Using Various Maximum-Intensity Projection Computed To Mography Image Sets For Stereotactic Body Radiation Therapy, David A. Zamora

Dissertations and Theses (Open Access)

The motion of lung tumors during respiration makes the accurate delivery of radiation therapy to the thorax difficult because it increases the uncertainty of target position. The adoption of four-dimensional computed tomography (4D-CT) has allowed us to determine how a tumor moves with respiration for each individual patient. Using information acquired during a 4D-CT scan, we can define the target, visualize motion, and calculate dose during the planning phase of the radiotherapy process. One image data set that can be created from the 4D-CT acquisition is the maximum-intensity projection (MIP). The MIP can be used as a starting point to …

An Implantable Mosfet Dosimeter Modified To Act As A Fiducial Marker, Joseph S. Dick

Dissertations and Theses (Open Access)

In external beam radiation therapy, it is imperative that the prescribed dose is administered to the correct location and in the correct amount. Though several ex vivo methods of quality assurance are currently employed to achieve this goal, verifying that the correct dose is received within the patient in situ is impossible without the capability of measuring dose inside the patient. Recently, a method of measuring dose delivered within the patient has been developed, an implantable MOSFET dosimeter. This dosimeter is implanted within the patient and records the dose received. Since the dosimeter is implanted in the patient, it could …

The Vision Of Toxicity Testing In The 21st Century: Moving From Discussion To Action, Melvin E. Andersen, Daniel Krewski

Toxicology and Animal Models in Research Collection

Over the past year, a series on commentaries have appeared in the Toxicological Sciences Forum Series related to the 2007 National Research Council (NRC) publication, Toxicity Testing in the 21st Century: A Vision and A Strategy. The first article in the series provided an overview of the vision and was accompanied by an editorial by the three editors of Toxicological Sciences. During the past year, eight invited commentaries from the academic, industrial, and regulatory sectors have provided diverse perspectives on the vision, noted challenges to its implementation, and highlighted aspects of toxicity testing that were not addressed in …

A Modular One-Generation Reproduction Study As A Flexible Testing System For Regulatory Safety Assessment, Richard Vogel, Troy Seidle, Horst Spielmann

Experimentation Collection

The European Union’s Registration, Evaluation and Authorisation of Chemicals (REACH) legislation mandates testing and evaluation of approximately 30,000 existing substances within a short period of time, beginning with the most widely used “high production volume” (HPV) chemicals. REACH testing requirements for the roughly 3000 HPV chemicals specify three separate tests for reproductive toxicity: two developmental toxicity studies on different animal species (OECD Test Guideline 414) and a two-generation reproduction toxicity study (OECD TG 416). These studies are highly costly in both economic and animal welfare terms. OECD TG 416 is a fertility study intended to evaluate reproductive performance of animals …

Practical Considerations In Regenerative Medicine Research: Iacucs, Ethics, And The Use Of Animals In Stem Cell Studies, Susan Vandewoude, Bernard E. Rollin

Biomedicine and Animal Models in Research Collection

The intent of US federal laws mandating IACUC review of animal-related activities was to satisfy contemporary socioethical concerns by introducing deliberations about ethics and animal welfare into the research process when animals are used. These laws and the system they chartered have worked well for the most part in providing opportunities for consideration of animal welfare as a vital part of animal research. As a result, investigators today are far less naïve about the ethical issues raised by research on animals and typically more sympathetic about the need for such consideration. As evidence of this growing awareness, the literature on …

Development And Validation Of A Measurement Scale To Analyze The Environment For Evidence-Based Medicine Learning And Practice By Medical Residents, Fangqiong Mi

Wayne State University Dissertations

A growing number of residency programs are instituting curricula to include the component of evidence-based medicine (EBM) principles and process. However, these curricula may not be able to achieve the optimal learning outcomes, perhaps because various contextual factors are often overlooked when EBM training is being designed, developed, and implemented. The purpose of the study was to develop and validate an instrument, the EBM Environment Scale, to analyze the environment for EBM learning and practice as perceived by medical residents.

The development of the EBM Environment Scale underwent the process of content domain identification, item generation, review by content experts …