Medicine and Health Sciences Commons^™

Chest Computed Tomography And Magnetic Resonance Imaging Texture Measurements Of Chronic Obstructive Pulmonary Disease, Maksym Sharma

Electronic Thesis and Dissertation Repository

Pulmonary imaging using computed tomography (CT) and magnetic resonance imaging (MRI) provide a method to measure airway and parenchymal pathologic information that cannot be provided using spirometry. Currently, it remains difficult to predict which chronic obstructive pulmonary disease (COPD) patients will worsen using spirometry, which although safe and inexpensive, does not provide small airway information where COPD is believed to initiate. Quantitative CT and MRI measurements provide regional structure and function information but are not included in mortality risk assessments, prognosis, or COPD staging. Therefore, my overarching hypothesis is that CT and MRI ventilation texture measurements combined with machine learning …

Resolving The Longitudinal Triglyceride Phenotype Of Heterozygous Lpl And Apo A-V Deficiency, Shehan D. Perera

Electronic Thesis and Dissertation Repository

Hypertriglyceridemia (HTG) is a risk factor for cardiovascular disease. However, only the triglyceride (TG) phenotype produced by biallelic loss-of-function (LOF) variants in the canonical TG metabolism genes is well understood. The TG phenotype produced by monoallelic LOF variants is poorly understood. We aimed to evaluate the TG phenotype associated with monoallelic LOF variants in the canonical TG metabolism genes.

Next-generation sequencing panel was employed to identify patients heterozygous for LOF variants in two of the canonical TG metabolism genes LPL and APOA5, followed by chart review to determine baseline and longitudinal TG phenotype in these patients.

My findings suggest …

Structure And Function Of Long-Covid Evaluated Using Pulmonary Imaging, Harkiran Kaur Kooner

Electronic Thesis and Dissertation Repository

The COVID-19 pandemic has resulted in millions of global respiratory infections, ranging in severity from asymptomatic to fatal. One of the many consequences of the pandemic is the emergence of long-COVID, which is an umbrella term used to describe the long-term sequelae and poor quality-of-life following recovery from acute COVID-19 infection. However, the pathophysiology and mechanisms responsible for the heterogenous manifestation of long-COVID remain poorly understood. Hyperpolarized ¹²⁹Xe magnetic resonance imaging (MRI) provides a non-invasive and radiation-free method to regionally visualize and quantify inhaled gas distribution and ventilation in vivo. A strong foundation for the use of pulmonary …

Validation Of A Virtual Auditory Space, And Its Use To Investigate How Pitch And Spatial Cues Contribute To Perceptual Segregation Of Auditory Streams, Nima Zargarnezhad

Electronic Thesis and Dissertation Repository

The human auditory system can decompose complex sound mixtures into distinct perceptual auditory objects through a process (or processes) known as Auditory Scene Analysis. Pitch and spatial cues are among the sound attributes known to influence sequential streaming (Plack 2018). In this project, the fidelity of a virtual acoustic space (the Audio Dome) in reproducing precisely located sound sources with a 9^th-order ambisonics algorithm was validated. The estimated horizontal Minimum Audible Angles aligned with previously reported values (Mills 1958) homogeneously across the space, and a robust low-frequency presentation was identified. Then, the Audio Dome was utilized to test …

The Impact Of Simulated Image Acquisition Time Reduction On Image Quality And Parameters Of Myocardial Perfusion Imaging Using A Dedicated Cardiac Camera, Alireza Khatami

Electronic Thesis and Dissertation Repository

Heart disease is the second leading cause of death in Canada, highlighting the crucial role of early diagnosis in disease management. Myocardial perfusion imaging (MPI), is widely employed for this purpose, involves injecting a radiopharmaceutical into the body, imaging its distribution with a gamma camera, and revealing cardiac blood flow patterns. A significant challenge in MPI is the lengthy 8 to 10 minutes required for stress and rest imaging, potentially causing patient discomfort and compromising image quality due to movement. In a clinical study with 26 patients, post-processed data manipulation simulated a reduction in MPI imaging time. The findings indicated …

Development Of Ph-Weighted Magnetic Resonance Imaging In The Spinal Cord: Application In Degenerative Cervical Myelopathy, Alicia E. Cronin

Electronic Thesis and Dissertation Repository

Degenerative cervical myelopathy (DCM) is a degenerative disease of the spinal cord that can lead to neurological dysfunction. It has been hypothesized that ischemia and hypoxia in the spinal cord at the site of compression could impact functional recovery after decompression surgery. Unfortunately, direct in-vivo quantification of hypoxia and ischemia in the spine has been limited in humans. Magnetic resonance imaging (MRI) can be utilized to measure hypoxia indirectly in soft tissue. Specifically, chemical exchange saturation transfer (CEST) is an MRI contrast that can be derived from the transfer of magnetization from selectively excited endogenous protons to bulk water protons. …