Master of Science (MS), Wright State University, 2024, Computer Science

Occupationally-acquired infections impact thousands of healthcare workers (HCWs) in the U.S., with many cases preventable through proper use of personal protective equipment (PPE). This study seeks to develop a robust system to enhance PPE compliance and reduce infection risks among HCWs. The objectives of this thesis are twofold: (1) to create a hybrid machine learning model that combines object detection and keypoint detection to ensure correct donning and doffing of PPE, and (2) to design a real-time feedback system using LED indicators and a display interface to offer actionable guidance to HCWs during PPE usage. The goal is to optimize the ML model for accurate PPE detection and evaluate its performance in IoT and edge systems for real-time feedback, ensuring effective user interaction. This approach aims to promote safer healthcare environments by improving PPE compliance and minimizing exposure risks. The findings of this thesis demonstrate that the developed model is compact, secure, and capable of real-time performance, making it well-suited for IoMT frameworks.

Doctor of Philosophy, The Ohio State University, 2024, Electrical and Computer Engineering

Medical imaging has revolutionized patient care, enabling noninvasive and detailed visualization critical for diagnosing and treating numerous conditions. However, interpreting complex medical images remains challenging, requiring specialized expertise often unavailable in rural or underserved areas. Advances in artificial intelligence (AI) have introduced significant potential to automate and enhance medical imaging, yet the size and computational demands of current deep learning models hinder scalability in real world applications, particularly in resource constrained settings. This dissertation addresses these challenges by developing advanced, lightweight neural network architectures that bring efficient and high-performing AI-driven medical imaging solutions to a broader audience. In particular we explore various deep learning approaches to systematically address key bottlenecks, drawing on lessons learned from each method to drive improvements across others. We investigate Graph Neural Networks (GNNs) as a compact, efficient alternative to traditional deep learning models, enabling targeted analysis that minimizes unnecessary background processing. We further enhance contextual understanding through lightweight Vision Transformers, optimizing self attention complexity to improve model efficiency. Additionally, we introduce an efficient Convolutional Neural Network (CNN) design that captures larger receptive fields without increasing computational burden, supporting both 2D and 3D imaging. Finally, we propose hybrid CNN Transformer architectures that combine CNNs' local feature extraction strengths with Transformers' global context capabilities, offering scalable, high performing solutions for diverse medical imaging applications. These contributions advance the development of accessible, AI based imaging tools that can be deployed on handheld devices and support critical applications in underserved areas, military operations, and emergency response, ult (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Health and Rehabilitation Sciences

Work-related musculoskeletal disorders/injuries (WRMSDs/WRSMIs) are chronic conditions, attributed to occupational duties and can affect one's ligaments, muscles, and tendons. One group of occupational workers that are prone to this type of injury are diagnostic medical sonographers. Sonography is a diagnostic imaging technique that utilizes high-frequency acoustic energy, emitted by transducers, to conduct diagnostic examinations of the human body and collect screening and diagnosis information. The transducer and ultrasound equipment system's instrumentation are solely controlled by a sonographer. Within sonography, there are multiple sub-specialties, which are devoted to diagnostic examination specific but not limited to vascular, abdominal, cardiac, and obstetrics/gynecology (OB/Gyn). A sonographer's risk for injury and episodes of musculoskeletal discomfort can be exacerbated by examining obese patients, performing bedside examinations, and maneuvering ultrasound equipment systems. It is important to note that 90% of sonographers and vascular technologists perform sonograms in pain.1 Along with WRMSDs, occupational burnout is commonly reported in healthcare. Disruptions in workflow, high workloads, short appointment times, and distractions may contribute to occupational burnout in sonographers. Globally, there is ongoing research, specific to sonographer ergonomics and ways to improve their working conditions. For example, in South Korea an ergonomic design was developed that combined the ultrasound equipment system and the patient's bed, such that the height and angle of the bed were remoted controlled. Additionally, this ergonomic design also provided a support device to suspend and lift the cables on the transducers.2 Additionally, several surveys have been administered to sonographers to better understand their job demands, wellbeing, and available resources. Hall et al (2024)3 reported that 97% of sonographers expressed “unrealistic workloads, tim (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Vision Science

Purpose: 1) To illustrate soft contact lens-induced optical distortion (apparent indentation) in optical coherence tomography (OCT) imaging and compare methods of correction utilizing contact lens thickness measurements. A previously published method (subtracting the amount the contact lenses distorts a hard, unindentable surface, such as a glass slide, from the corresponding distorted contact lens thickness imaged on an eye) is compared to software that automatically applies the appropriate refractive index of the contact lens to the raw image. 2) To evaluate the impact horizontal visible iris diameter (HVID) and central corneal curvature (Ks) have on ocular sagittal depth and the advantages of anterior segment OCT imaging for contact lens fittings. 3) To assess the comfort and movement of two different diameter options of the same custom soft lens in those with smaller HVIDs than the population mean. Methods: 1) Three contact lens brands (Acuvue Oasys Hydraclear Plus, Air Optix Night and Day, and Ultra) were imaged twice with the Visante Anterior Segment OCT (Carl Zeiss Meditec, Dublin, CA) on the provided test eye with the eye pointed directly into the instrument (primary gaze) and also when simulating lateral gaze. Each lens was dotted with a metallic Sharpie 1 mm in from the edge to serve as a visible landmark during imaging and measurement for accurate comparisons. A raw, unadjusted (warped) image of the contact lens on a glass slide was used to quantify distortion, then was subtracted from both straight and lateral gaze image raw contact lens thicknesses. Additionally, raw primary and lateral gaze images were also transformed using custom Matlab software to apply the appropriate contact lens refractive index. This method was validated by showing the test eye cornea thickness and curvature were equal under and not under a contact lens, as well as equal to the Visante's own internal caliper measurement of the corrected (dewarped) bare test eye. All thick (open full item for complete abstract)

Doctor of Philosophy, University of Toledo, 2024, Mechanical Engineering

Particle-laden flows, characterized by the motion of discrete solid particles or droplets within a continuous carrier medium, are ubiquitous in various fields, spanning from environmental phenomena to industrial processes. Understanding these complex flows, particularly within intricate biological systems such as the human aorta, presents significant challenges and opportunities in fundamental and applied research. This study investigates the passive control of the fate of embolic particles in the aorta grafted with the cannula of a left ventricular assist device (LVAD). An LVAD is a mechanical heart-assist pump that is used for severe heart failure patients awaiting heart transplants or as a permanent therapy. A risk factor with this type of device is the transport of blood clots (formed in the left ventricle or within the pump) to the brain vasculature bed, leading to an ischemic stroke event. Previous studies have highlighted the influence of the cannula-aorta graft angle on hemodynamics and particle trajectories. However, there have been inconsistencies across numerical simulations, as well as a sore lack of experimental validations. This has served as the motivation for this dissertation to design and develop a robust experimental-based framework to study the transport of inertial particles in a biofluidic setting. The framework has been complemented by high-fidelity computational studies. For the geometry, four patient-specific cases as well as two idealized aortic computer-aided design (CAD) models have been developed and used for experimental and numerical analyses. The idealized model development process integrates statistical data from the literature alongside morphological parameters extracted from the recruited patients' models. A set of experimental studies is conducted to investigate the dynamics and trajectories of particles within the developed aortic models. Water has been used as the working fluid at two target flow rates o (open full item for complete abstract)

Doctor of Education , University of Dayton, 2024, Educational Administration

Cardiovascular disease continues to be the number one killer of women in America, yet barriers to lifesaving healthcare increase (Centers for Disease Control and Prevention, 2022). Incidence of sexism in medicine proves to be a leading cause of these barriers including underrepresentation of female patients in crucial research studies, lack of understanding and education of female specific cardiac symptoms, and the underutilization of advanced diagnostic imaging tests for female patients who could produce suboptimal results in lesser diagnostic testing causing misdiagnosis. Feminist critical theories were used to challenge the gender gap within the medical field and research along with the communities of practice theory, showing how embedded sexism to the medical field creates an unconscious social learning upholding norms. Practical action research was used to conduct this study due to the direct connection between testing and diagnosis of patients, having the potential to make an impact on patient care on a larger scale. Research was conducted utilizing HIPAA compliant cardiology patient data obtained to observe the ordering patterns of physicians within cardiology practices. An anonymous Physicians' Knowledge of PET Eligibility and Symptoms for Female Patients scale survey was used to collect data from practicing cardiologists to view opinions, attitudes, and education around female specific cardiac symptoms. This data was analyzed using Chi-square tests to understand the relationship between various factors such as qualifying ICD-10 (diagnosis) codes, sex of the patient, and qualification for a cardiac PET scan. The results show that there was no significant relationship between sex and if the patient qualified for a cardiac PET scan, showing that physicians have a lack of understanding of the incredible benefits of cardiac PET for female patients, who are exceptional candidates for PET due to attenuation artifacts. Results also show a positive statistical rela (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Anatomy

Introduction Lung cancer is prevalent and deadly and contributes to approximately 25% of all cancer-related mortalities. With incidence rates rising globally, new treatment options have increased patient overall survival. Lung cancer is unique from other cancer types in that there is a correlation between a patient's body mass index (BMI) and overall survival. Sarcopenia is a skeletomuscular system disorder characterized by a loss of skeletal muscle mass, size, and function. It is identified to be correlated with worse treatment outcomes and survival in several cancer types. Thus, this study explored the relationship between anatomically measured sarcopenia and survival. We hypothesized that sarcopenia would be correlated with a worse overall survival among patients with non-small cell lung cancer. Additionally, we tested two anatomically different measurement methods. Methods We abstracted data from both chest and abdominal CT scans from 22 patients consented and enrolled in the FITNESS Study: Longitudinal Geriatric Assessment, Treatment Toxicity, and Biospecimen Collection to Assess Functional Disability Among Older Adults with Lung Cancer at the Ohio State Wexner Medical Center's James Cancer Hospital and Solove Research Institute. Using the NilRead software, the skeletal muscle index (SMI) was analyzed by finding the paravertebral muscles at the T12 level, and the psoas major muscle at the L3 level, and manually tracing it to calculate the SMI. Additionally, the patient's weight, in kg, and height, in meters, were used to calculate their BMI as the same date of their baseline CT scans. The patient's body mass index (BMI) and SMI values for both methods were analyzed and further assessed by patient sex. From there, previously established equations were utilized to calculate the sarcopenic and normal range SMI values for both methods. Next, univariate and multivariate Hazard Cox Ratio tests were run to analyze the impact on survival. A paired samples T-Test wa (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2024, Biophysics

Cardiovascular disease affecting both the heart and the vasculature is the leading cause of death worldwide. Canonical origins of heart disease are the primary, established risk factors for the development and progression of heart disease (e.g., aging and obesity). Non-canonical origins of heart disease, in contrast, are indirect, occurring through exposures during development, specifically in-utero, and creating a predisposition for disease (e.g., maternal psychosocial stress). By understanding the multifaceted nature of heart disease etiology, clinical and basic researchers can develop more comprehensive understandings and treatment approaches to predispositions, improving prevention, diagnosis, and prognosis of heart disease. Currently, animal studies lack the comprehensive understanding of canonical and noncanonical origins of disease on heart function and cardiac reserve. Our studies explore the detailed in vivo heart health of mouse models of canonical and noncanonical origins of heart disease. Speckle tracking echocardiography has emerged as a powerful tool that can provide information about heart structure and function that is essential to diagnosis and prognosis of heart disease. Speckle tracking provides indices of systolic function, diastolic function, and load-independent parameters for contractility which cannot be obtained by classical M-mode measurements of the left ventricle. Further, these studies include the development of novel method to non-terminally assess cardiac reserve in vivo in mice via the Frank-Starling mechanism and sympathetic stimulation. In Chapter 2, we demonstrate that canonical origins of disease (aging mice and obese mice) have distinct functional phenotypes and cardiac reserves. At baseline, aging mice and obese mice have preserved cardiovascular and heart performance with blunted systolic function, diastolic function, and contractility. This is due to the changes in structure during both aging and obesity which induce hypert (open full item for complete abstract)

Doctor of Healthcare Administration (D.H.A.), Franklin University, 2024, Health Programs

The United States pediatric population is unique in that the epidemiological trends differ from those seen in the adult population. When discussing the pediatric emergency department (ED), this is typically a setting with high patient flow which requires swift diagnoses and treatment. Ideally, all patients should have equal opportunity to receive their highest possible level of quality healthcare, regardless of social determinants of health (SDOH) such as patient race/ethnic background, preferred spoken language, socioeconomic status, and insurance status. This is essentially the concept of health equity. The goal is to provide responsible and ethical healthcare to patients. If healthcare delivery is disproportionate, this may result in the overcrowding of EDs, delays in patient care, economic burden on the healthcare system, and increased morbidity and mortality. Some scholars have claimed that both individual and systemic biases have resulted in inequitable healthcare delivery. The following research study investigated health equity in the United States pediatric ED via the following question: What government and organizational policy changes can be made to enhance ED pediatric patient equity by utilizing first-hand information from ED physicians? The selected methodology for this research was qualitative and utilized in-depth semi-structured interviews of 15 pediatric ED physicians via Franklin University's Zoom platform. ATLAS.ti software was used to assist in identifying key themes and sub-themes from the code transcriptions.

Doctor of Philosophy, Case Western Reserve University, 2024, Clinical Translational Science

The limbic system (LS) regulates emotions, memory, and behavior. Dysfunction in LS regions such as the hippocampus, amygdala, and prefrontal cortex has been associated with mental health and behavioral disorders that often begin during childhood and adolescence. Previous studies indicate that parental internalizing problems (e.g. anxiety, depression) and externalizing problems (e.g. substance abuse, aggression) can negatively impact a child's mental health, behavior regulation and brain development. While prior research has largely focused on clinical populations, this dissertation examines whether subtle variation in parental and child behavior problems relates to LS volumes in typically developing children and adolescents. This study uses data from the general population in the United States collected by Adolescent Brain Cognitive Development (ABCD) Study Group. The dissertation had two main aims: (1) assess relationship between subclinical parental behavior problems and children's LS brain structure volumes using structural MRI, and (2) investigate associations between normative child behavior problems and LS structures using structural and diffusion MRI. The findings reveal distinct patterns of LS development in children and adolescents based on parental internalizing and externalizing behaviors. Gender-specific differences in these patterns also emerged, suggesting potential variations in risk profiles for later onset mental disorders. This highlights the importance of considering parental mental health when addressing behavior problems in children and adolescents. Additionally, the identified associations between child behavior problems and limbic structures underscore the potential for early intervention to prevent clinical symptoms onset and atypical brain development. Strong associations were also found between externalizing (and internalizing) problems and reduced LS white matter volumes, emphasizing the need for targeted support in emotionally (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 2024, Biomedical Engineering

Pancreatic ductal adenocarcinoma (PDAC) presents significant challenges in both diagnosis and treatment due to its aggressive nature and limited therapeutic options. Currently, highly sensitive imaging tools for assessing disease progression and tumor invasion are lacking, exacerbating issues with detection and therapeutic planning. The tumor microenvironment of PDAC plays a substantial role in determining tumor progression and makes staging difficult by establishing pre-metastatic niches. Magnetic resonance molecular imaging (MRMI) is a technique that employs contrast agents targeted to cancer-associated biomarkers. Previously, our lab developed a gadolinium contrast agent targeted to fibronectin for detecting and diagnosing cancerous lesions. In this study, we employed MRMI targeting the oncofetal protein EDB-FN, which is overexpressed in tumors in accordance with stage and grade, to monitor immunotherapies in a mouse model of PDAC. By leveraging the complex tumor microenvironment and targeting fibronectin, a known regulator of PDAC progression, MRMI was able to monitor tumors. Tumors were treated with gene therapy aimed at regulating fibronectin expression, validating that tuning fibronectin and EDB-FN produces discernible changes in MRMI signal. Additionally, in immunotherapy studies, MRMI predicted therapeutic outcomes in mice based on enhancement patterns observed during early treatment phases with novel immunotherapeutic regimens and saline controls. Correlations between signal intensity and changes in tumor response following therapy were identified, enabling classification of mice into responders and non-responders based on immunological studies and histological analysis. These findings demonstrate the potential of MRMI for immunosurveillance in PDAC. It also highlights its ability to non-invasively assess immunotherapy response, thus addressing critical challenges in PDAC management. In doing so, we have built upon existing literature and established EDB-F (open full item for complete abstract)

Master of Athletic Training, Marietta College, 2024, Athletic Training

Objective/Context: This research study aims to investigate changes, if any, to cardiovascular screening in the pre-participation physical examination (PPE) in the collegiate setting following the COVID-19 pandemic. The study aimed to identify modifications made to the PPE process along with certified athletic trainers' (ATs) perceptions of cardiac conditions occurring in Division III college athletes. Design and Setting: Cross-sectional online survey. Participants: The participants for this study were Division III Head ATs, with at least five years of experience in their current role and actively involved in collegiate athletics within the Midwest NATA districts 4, 5, and 11. This study was sent to 121 ATs and completed by 19 participants. Intervention: Participants completed an electronic survey consisting of demographic questions and questions about the PPE process. The survey collected data on baseline components of the cardiovascular assessment in the PPE process before COVID-19, modifications if any to the PPE process post-COVID-19, and ATs' perceptions of cardiac conditions among college athletes since COVID19. The survey instrument was distributed via email using the Microsoft Forms online platform. Data was collected over a five-week period. The research team developed the survey. The validity of the survey was assessed through experts in the field. Main Outcome Measurement: The survey assessed changes in the PPE process specific to cardiovascular health and ATs' perceptions of cardiac conditions for student athletes prior to and after COVID19. Results: Findings revealed consistent baseline components of the cardiovascular assessment in the PPE process before and after COVID-19, with minimal modifications made to the cardiovascular screening process post-pandemic. ATs reported stable perceptions of cardiac conditions among college athletes, with no significant increase post-COVID-19. The majority of respondents did not observe a rise in the prevalence (open full item for complete abstract)

Master of Engineering, Case Western Reserve University, 2024, Biomedical Engineering

Radiomic analysis of individual regions or acquisitions has shown significant potential for predicting treatment response to neoadjuvant therapy in rectal cancers via routine MRI. We present a novel multi-plane, multi-region radiomics framework for exploiting intuitive clinical and biological aspects of rectal tumor response on MRI. Using a multi-institutional cohort of 151 baseline T2-weighted axial and coronal rectal MRIs, 2D texture features were extracted from multiple regions of interest (tumor, tumor-proximal fat) across both axial and coronal planes, with machine learning analysis to identify descriptors predictive of complete response to neoadjuvant therapy. Our multi-plane, multi-region radiomics model was found to significantly outperform single-plane or single-region feature sets with a discovery area under the ROC curve (AUC) of 0.765±0.054, and hold-out validation AUCs of 0.700 and 0.759. This suggests multi- region, multi-plane radiomics could enable detailed phenotyping of treatment response on MRI and thus personalization of therapeutic and surgical interventions in rectal cancers.

Doctor of Philosophy, Case Western Reserve University, 2024, EECS - System and Control Engineering

This dissertation investigates the application of digital pathology for developing diagnostic and prognostic tools for 2 diseases: Biliary tract adenocarcinoma and Papillary Thyroid Carcinoma (PTC). We explore the realms of cytopathology, which studies exclusively the morphologies of epithelial cells, and histopathology, which includes the entire tissue region. Bile duct brush specimens are difficult to interpret as they often present inflammatory and reactive backgrounds due to the local effects of stricture, atypical reactive changes, or previously installed stents, and often have low to intermediate cellularity. As a result, diagnosis of biliary adenocarcinomas is challenging and often results in large interobserver variability and low sensitivity. In this dissertation, we first used computational image analysis to evaluate the role of nuclear morphological and texture features of epithelial cell clusters to predict the presence of biliary tract adenocarcinoma on digitized brush cytology specimens. We improved the sensitivity of diagnosis with a machine learning approach from 46% to 68% when atypical cases were included and treated as nonmalignant false negatives. The specificity of our model was 100% within the atypical category. PTC is the most prevalent form of thyroid cancer, with the classical form and the follicular variant representing the majority of cases. Despite generally favorable prognoses, approximately 10% of patients experience recurrence post- surgery and radioactive iodine therapy. Attempts to stratify risk of recurrence have relied on gene expression-based prognostic and predictive signatures with a focus on mutations of well-known driver genes, while hallmarks of tumor morphology have been ignored. In this dissertation, we introduce a new computational pathology approach to develop prognostic gene signatures for thyroid cancer that is informed by quantitative features of tumor and immune cell morphology. We show that integrating gene express (open full item for complete abstract)

Master of Science in Computer Engineering, University of Dayton, 2024, Electrical and Computer Engineering

Chest X-rays (CXRs) are one of the most common medical imaging procedures providing two-dimensional (2D) images of three-dimensional (3D) density data regarding a patient's chest. Computed tomography (CT) scans give a more extensive look at a desired location by utilizing X-rays to provide a 3D view of a specified area of the human body in slices. CT scans are quintessential for getting lung measurements as well as identifying and tracking lung cancer nodule growth within said lungs. Many different computer aided detection (CAD) systems have the ability to read CT scan data and assist medical professionals in outlining essential information within the lungs such as providing lung outlines, detecting lung nodules, and more. The ability for a CAD system to take advantage of lung thickness information would assist with bounding CAD systems but also providing algorithms with information that can assist in determining the likelihood of a nodule present in certain lung areas. In this approach, a method by which CT scans are converted into synthetic CXRs is introduced. In the process of generating these synthetic CXRs, a corresponding set of relative 2D lung thickness values is generated for each pixel in which the lung exists within a scan as a beam travels through the lung from front to back. A regression neural network (RNN) is then created based on U-Net architecture to train a model to predict the relative thickness of the lungs using the data from the synthetic CXR generation. CT scans from the Lung Image Database Consortium-Image Database Research Initiative (LIDC-IDRI) are used to generate synthetic CXRs and the associated lung thickness data. After the data has been processed, scaled, and augmented, it is used to train and test the U-Net RNN, which can predict relative lung thickness in other synthetic CXRs with an overall mean absolute error (MAE) of 0.0301 and an overall mean squared error (MSE) of 0.0047.

DNP, Otterbein University, 2025, Nursing

In the United States, around 40,000 surgeries are conducted on pediatric patients yearly to address congenital heart disease. These surgeries involve a variety of complications beyond cardiovascular problems, including pain management. Traditional pain management involving intravenous opioids has drawbacks such as sedation, respiratory depression, and prolonged recovery times. As the healthcare industry moves away from opioid-centric pain management, the use of multimodal analgesia, including ultrasound-guided regional anesthesia, is being utilized. Regional anesthesia techniques, such as the transversus thoracis muscle plane block and the thoracic erector spinae block, are being considered for the ability to provide adequate pain relief while reducing opioid usage. The goal of using ultrasound blocks for congenital heart patients is to decrease postoperative opioid consumption and decrease the time to extubation in pediatric cardiac surgical patients in the first 24 hours postoperatively. A 12-month timeline outlines the development of guidelines, staff training, and clinical practice change integration. The project follows the Iowa Model for Evidence-Based Practice to guide its implementation, focusing on reducing opioid use, improving postoperative outcomes, and enhancing patient safety.

DNP, Otterbein University, 2025, Nursing

Effective airway management is critical for nurse anesthetists, encompassing tasks such as anesthesia administration, airway establishment, and patient safety, particularly in challenging cases where airway difficulties may arise. The subjectivity in airway assessments poses challenges for clinicians when accurately predicting difficult cases. Point-of-care ultrasound (POCUS) has emerged as a valuable tool for quantifying airway parameters, providing objective data to guide decision-making. This project aims to establish evidence-based guidelines for managing the airway in unconscious trauma patients requiring intubation using POCUS. By quantifying parameters such as PEP/E-VC ratios, hyomental distance, thyrohyoid membrane thickness, and anterior neck thickness, healthcare providers can make more informed decisions and potentially reduce malpractice settlements associated with anesthesia-related complications. The project follows the John Hopkins Evidence-Based Practice (JHEBP) Model, a systematic approach for incorporating research findings into patient care. Data collection will involve retrospective chart analysis to assess compliance in documenting airway parameters and using POCUS in difficult cases. The project will monitor CL grade III or IV classifications in patient records to identify trends and evaluate the application of POCUS in managing difficult airways. The timeline spans seven months, including planning, education, training, and data analysis. The ER staff will use a portable handheld ultrasound device, Vscan Air, to efficiently perform scans on all ER patients. This project seeks to enhance airway management in unconscious trauma patients, improve clinical outcomes, and reduce the risk of adverse events, ultimately benefiting anesthesia and emergency room providers and patients.

Master of Science, The Ohio State University, 2024, Vision Science

Purpose: Spaceflight Associated Neuro-ocular Syndrome (SANS) is experienced by astronauts in microgravity and is characterized by a hyperopic shift, globe flattening, optic disc edema and choroidal folds. The pathophysiology of SANS is not yet known, but it is thought to be caused by the loss of ground-based hydrostatic pressure gradient, which results in a head-ward fluid shift. It has been recently hypothesized that this fluid shift elicits congestion of the orbital fat. Thyroid eye disease (TED) may be a novel terrestrial analog to SANS because the physical manifestations in both pathologies can be similar. The purpose of this study is to assess the performance of an established magnetic resonance imaging (MRI) sequence to measure fat/water fractions in the orbit, first in phantoms and then in one initial TED subject. Methods: Fat-water fractions in orbital phantoms were quantified using a q-Dixon Multi-Echo Chemical Shift Encoded MRI at 3 Tesla. Images were acquired in triplicate to evaluate test-retest reliability, as well as in 3 orientations. The first subject with TED was enrolled, provided informed consent, and triplicate orbital images were acquired. These images were processed with the imaging software ImageJ and orbital fat volume and fat fraction measurements were obtained from selected orbital fat. Results: The MRI sequence measured fat-fraction in the phantom models with good accuracy, and there was a strong linear association in all three positions between measured fat values and true fat values (R2 = 0.9978). The sequence was found to be repeatable, with good test-retest reliability between the positions and with triplicate acquisitions. Preliminary results for the initial TED subject show successful procurement of overall average fat-fraction (approximately 43% fat in the right orbit and 42% in the left orbit). Statistical analysis suggests generally good agreement between the triplicate scans, with low coefficient of variation in both orbits (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Comparative Biomedical Sciences

Modic changes (MC) are signs of vertebral pathology visible on magnetic resonance (MR) images that have been associated with low back pain (LBP) and disc degeneration in people. Multiple breeds of dogs also develop MCs and coincidental back pain. However, the association between breed, MC, and spinal pathologies has yet to be fully elucidated. This study aimed to identify the prevalence of MC that occur spontaneously in the lumbar vertebral column of dogs diagnosed with intervertebral disc disease (IVDD) and examine their association with demographic criteria and the disc width index (DWI). Medical records and lumbar vertebral column MR images were examined from 104 dogs (831 intervertebral disc spaces and adjacent vertebrae), which were divided into three groups: chondrodystrophic dogs (CD; n= 54) and non-chondrodystrophic dogs (NCD; n= 30) with IVDD as the primary diagnosis, and control dogs (n= 20) with other spinal diseases as their primary diagnosis. Results demonstrate increasing age and a diagnosis of IVDD were significantly associated with MC in dogs (p< 0.001 and p= 0.0062, respectively). In CD dogs with IVDD, Type 2 MC were most prevalent, whereas, in NCD dogs, Type 3 MC were the most prevalent type. Type 2 MC were distributed nearly equally across the lumbar vertebral column, while Type 3 MC were primarily detected at the level of L7-S1. This study demonstrated that MC developed spontaneously in dogs, are common in dogs diagnosed with IVDD, and the type observed varies by breed. Further research is needed to understand the pathogenesis of MC; however, the increased presence of Type 2 MC in CD dogs, similar to what is found in people with disc degeneration, suggests that CD dogs could serve as models for MC in people.

Doctor of Philosophy, Case Western Reserve University, 2024, Biomedical Engineering

Ultrasound (US) is safe and low-cost relative to other imaging technologies, making it an increasingly popular diagnostic modality. US contrast is often limited by relatively low differences in acoustic impedance in the body, necessitating the use of contrast agents like microbubbles (MBs; ~1-10 µm diameter) which are intravenously injected and used to compensate for low contrast in conventional B-mode US imaging. The large size of MBs, however, limits their applications to the blood pool. In many diseases, including cancer, information beyond the blood pool is needed for diagnosis and staging. For instance, in many cancers (e.g. prostate, mammary, ovarian etc.), tumors are characterized by high vascular permeability and low lymphatic drainage, which increases the potential for enhanced permeability and retention (EPR) of macromolecules (~200 nm). When present, EPR leads to the tumor-localized accumulation of nano-agents. Nanobubbles (NBs) are new-age submicron bubble agents (100-500 nm diameter) capable of extravasation beyond the vascular network while providing enhanced US contrast similar to MBs. Recently, our group showed that active targeting of NBs to prostate specific membrane antigen (PSMA) rapidly and selectively enhances tumor accumulation and retention. These processes were visualized in real-time with clinical US. This project established NBs as a sensitive detection tool in the diagnosis of PSMA-positive prostate cancer due to localized NB accumulation, reduced diameter and higher number density (NBs per volume) of NBs compared to MBs of similar composition. Together, these points enable: 1) contrast visualization of small capillaries with higher fidelity, and 2) imaging of extravascular cellular targets reached via extravasation of NBs in leaky blood vessels while employing 3) a safe and widely accessible imaging modality. Together, contrast enhanced ultrasound (CEUS) using NBs (NB-CEUS) is a detection method with high biocompatibility and high safe (open full item for complete abstract)