Medicine and Health Sciences Commons^™

A Comparative Analysis Of Data Collection Systems Used In Radiography Educational Programs And The Role Mobile Electronic Devices Play, Robin S. Garner

Electronic Theses and Dissertations

Each radiography program has a system to collect important data from didactic and clinical settings in order to accurately assess the progress and success of students, provide the needed student intervention, and provide accreditation agencies with appropriate documentation that demonstrates student success in reaching program learning outcomes. The purpose of this research study was to determine the method of data collection and documentation used by radiography programs to evaluate student progress and to examine if MEDs play a role in evaluating and documenting student skills at the point of care.

The majority of radiography programs in this study were using …

Radiography Clinical Instructors' Perceptions Of The Transition From Technologist To Educator, Christina G. Lee

Electronic Theses and Dissertations

Radiologic technologists who transition into the role of clinical instructor are usually expert practitioners but may lack knowledge of best practices regarding student instruction and evaluation. The purpose of this phenomenological qualitative study was to investigate how CIs experience the transition from practitioner to educator and what knowledge or education of best practices of instruction and evaluation they bring to the position. This study consisted of interviews with radiography CIs from one associate degree radiography program in the southeastern part of the United States. While some CIs felt prepared to transition into the CI role, none of them had previously …

Voxel-Level Absorbed Dose Calculations With A Deterministic Grid-Based Boltzmann Solver For Nuclear Medicine And The Clinical Value Of Voxel-Level Calculations, Justin Mikell

Dissertations & Theses (Open Access)

Voxel-level absorbed dose (VLAD) is rarely calculated for nuclear medicine (NM) procedures involving unsealed sources or 90Y microspheres (YM). The current standard of practice for absorbed dose calculations in NM utilizes MIRD S-values, which 1) assume a uniform distribution in organs, 2) do not use patient specific geometry, and 3) lack a tumor model. VLADs overcome these limitations. One reason VLADs are not routinely performed is the difficulty in obtaining accurate absorbed doses in a clinically acceptable time. The deterministic grid-based Boltzmann solver (GBBS) was recently applied to radiation oncology where it was reported as fast and accurate for both …

Role Of Cerebrovascular Abnormality In Neurodegenerative Disease And Subcortical Ischemic Disease: Ct Perfusion And Pet Imaging, Jun Yang

Electronic Thesis and Dissertation Repository

Clinical studies indicate that about 30% ~ 50% of patients have cognitive impairment after the first or recurrent stroke. Ischemic injury, particularly subcortical lesions, caused by stroke has been demonstrated to further exacerbate cognitive impairment of Alzheimer’s disease (AD) and vascular dementia. However, the mechanisms whereby cerebrovascular abnormalities contribute to neurodegeneration at early stage of disease and eventually to cognitive decline remain unclear. CT perfusion and positron emission tomography (PET) were used to investigate early mechanisms in a rat comorbid model of cerebral ischemia (CI) and β-amyloid (Aβ, a pathological hallmark of AD) toxicity, and in patients with small subcortical …

Magnetic Resonance Imaging Compatible Remote Catheter Navigation System, Mohammad Ali Tavallaei

Electronic Thesis and Dissertation Repository

Many vascular and cardiac diseases are diagnosed and treated using a medical technique known as percutaneous transluminal catheter intervention (PTC). In PTC, the interventionalist inserts a catheter into the vasculature, and using the vessel as the guiding passageway, the catheter is navigated to desired anatomical targets where it would be used for various purposes such as catheter ablation for the treatment/management of cardiac arrhythmias. The catheterization procedure is conventionally guided with x-ray fluoroscopic imaging and more recently, but rarely, with Magnetic Resonance Imaging (MRI). X-ray imaging irradiates the patient directly during the procedure, and the staff and interventionalists indirectly through …

Ultrasound Evaluation Of Umbilical Coiling Index In Second Trimester Of Gestation And Its Association With Small For Gestational Age Status At Birth, Josephine Mwikali Ndolo

Theses & Dissertations

Introduction: The degree of coiling of the umbilical cord, referred to as umbilical coiling index, has been shown to have an effect on perinatal adverse outcomes such as small for gestational age neonates, interventional delivery, meconium staining, low fetal pH and low Apgar score. This study proposes that the antenatal umbilical coiling index performed in the second trimester of pregnancy has a correlation with the gestation-specific birth weight and can therefore be used as a marker to predict small for gestational age neonates.

Objective: To determine the association between antenatal umbilical coiling index (aUCI) in the second trimester and small …

Prevalence Of Suspicious Ultrasound Findings In Patients With Mammographic Focal Asymmetry At Aga Khan University Hospital, Nairobi, Jacqueline Ndunge Mavuti

Theses & Dissertations

Background: Breast cancer has become the leading cancer in women in both economically developed and developing countries, accounting for 25% of all cancers diagnosed worldwide in 2012. The cornerstone of breast cancer control remains early detection in order to improve outcomes and survival. Thus far the only breast cancer screening method that has proved to be effective is mammography. Although mammography is the mainstay of early detection, a fundamental limitation is its low inherent contrast difference between the soft tissue structures in the breast. Mammographic specificity relies on the ability to distinguish benign from malignant breast lesions based on their …

Comparison Of Quantitative Analysis To Qualitative Analysis For Interpretation Of Lower Limb Lymphoscintigraphy, Edward Chege Nganga

Theses & Dissertations

Background: Lymphoscintigraphy is now the primary imaging modality used in determining a diagnosis in patients with suspected extremity lymphedema. However, analysis is mainly by visual qualitative analysis which is subjective and has a wide inter-observer variability. Subtle differences in ilioinguinal uptake between normal and abnormal limbs may be missed with visual qualitative analysis. This study seeks to compare quantitative analysis to qualitative analysis by computing percentage ilioinguinal nodes uptake at 1.5 hours.

Objectives: To compare quantitative analysis to qualitative analysis of lower limb lymphoscintigraphy in the diagnosis of lymphedema.

To determine the diagnostic accuracy of quantitative lymphoscintigraphy analysis.

Methodology: 52 …

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

Dissertations & 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 …

Image Enhancement Of Cancerous Tissue In Mammography Images, Richard Thomas Richardson

CCE Theses and Dissertations

This research presents a framework for enhancing and analyzing time-sequenced mammographic images for detection of cancerous tissue, specifically designed to assist radiologists and physicians with the detection of breast cancer. By using computer aided diagnosis (CAD) systems as a tool to help in the detection of breast cancer in computed tomography (CT) mammography images, previous CT mammography images will enhance the interpretation of the next series of images. The first stage of this dissertation applies image subtraction to images from the same patient over time. Image types are defined as temporal subtraction, dual-energy subtraction, and Digital Database for Screening Mammography …

A Mobile Image Enhancement Technology For Visually Impaired, Fahao Qiao

Dissertations, Master's Theses and Master's Reports - Open

In this thesis, an image enhancement application is developed for low-vision patients when they use iPhones to see images/watch videos. The thesis has two contributions. The first contribution is the new image enhancement algorithm which combines human vision features. The new image enhancement algorithm is modified from a wavelet transform based image enhancement algorithm developed by Dr. Jinshan Tang. Different from the original algorithm, the new image enhancement algorithm combines human visual feature into the algorithm and thus can make the new algorithm more effective. Experimental simulation results show that the proposed algorithm has better visual results than the algorithm …

Bright Facet Sign And Its Association With Demographic And Clinical Variables, Gary Andrew Longmuir

Walden Dissertations and Doctoral Studies

Low back pain has a significant impact on global public health and economics. The bright facet sign (BFS), a common finding on magnetic resonance imaging (MRI) of the lumbar spine, is associated with low back pain. While degenerative joint disease (DJD) affects low back pain, its presence appears independent of the BFS at the disc and facet joints at the same spinal level. Increased BMI, considered a risk factor for DJD, has an inverse association with the BFS. The independent relationship of DJD and the BFS is poorly understood and may represent a previously unreported pain pathway. In this nested …

Computer Aided Diagnosis Of Oral Cancer: Using Time-Step Ct Images, Jonathan T. Scott

Masters Theses

"In medical imaging it is a very common practice to use a technique known as Time-Step imaging in patients who might develop cancer. Time-Step imaging it a very powerful technique, however it can lead to unmanageable amounts of image data. Previously the only way to search all of this data was to manually look through all of the files. This had to be done by trained professionals who knew what to look for within the images and make a judgment about the patient based on the images. This paper discusses the development of an algorithm to have a computer search …

Computer Aided Detection Of Oral Lesions On Ct Images, Shaikat Mahmood Galib

Masters Theses

"Oral lesions are important findings on computed tomography images. They are difficult to detect on CT images because of low contrast, arbitrary orientation of objects, complicated topology and lack of clear lines indicating lesions. In this thesis, a fully automatic method to detect oral lesions from dental CT images is proposed to identify (1) Closed boundary lesions and (2) Bone deformation lesions. Two algorithms were developed to recognize these two types of lesions, which cover most of the lesion types that can be found on CT images. The results were validated using a dataset of 52 patients. Using non training …

Phase Imaging Using Focusing Polycapillary Optics, Sajid Bashir

Legacy Theses & Dissertations (2009 - 2024)

The interaction of X rays in diagnostic energy range with soft tissues can be described by Compton scattering and by the complex refractive index, which together characterize the attenuation properties of the tissue and the phase imparted to X rays passing through it. Many soft tissues exhibit extremely similar attenuation, so that their discrimination using conventional radiography, which generates contrast in an image through differential attenuation, is challenging. However, these tissues will impart phase differences significantly greater than attenuation differences to the X rays passing through them, so that phase-contrast imaging techniques can enable their discrimination.

Grid-Based Fourier Transform Phase Contrast Imaging, Sajjad Tahir

Legacy Theses & Dissertations (2009 - 2024)

Low contrast in x-ray attenuation imaging between different materials of low electron density is a limitation of traditional x-ray radiography. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One recently developed phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a technique recently demonstrated by Bennett et al.1 …