Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

The Combined Effects Of Physical Exercise And Cognitive Training On Gait Speed And Primary Motor Cortex Metabolism In Individuals With Mild Cognitive Impairment: A 1h-Mrs Analysis, Jack Thomas Emsey Elkas

Electronic Thesis and Dissertation Repository

Mild cognitive impairment (MCI) is a transitional stage before dementia. Altered gait in MCI has been associated with progression to dementia. Using magnetic resonance spectroscopy, a relationship between primary motor cortex (M1) neurochemistry and dual task gait speed has been reported in MCI. Interventional research suggests exercise, cognitive training, and vitamin D supplementation may benefit MCI, yet the combined effect of these treatments on gait speed and M1 metabolism is unknown. Participants with MCI (N=75) were assigned to one of five intervention arms and dual task cost on gait speed and M1 metabolism was assessed before and five months after …

Rna Isolation In Duchenne Muscular Dystrophy (Dmd) Mice Models, Salem Abu Al-Burak

Undergraduate Student Research Internships Conference

Fibrosis is a progressive and typically irreversible disease process characterized by the excessive deposition of collagen in organs and in tissues of the musculoskeletal (MSK) system^1,2. This process, which causes loss of organ and tissue function, can be initiated by micro-traumas³, an excessive and/or prolonged immune response¹, the activation and proliferation of fibrosis-inducing progenitor cells⁴, and a pro-fibrotic extra-cellular microenvironment⁵. In parallel with the events that initiate fibrosis, genetic or environmental influences may cause cells and tissues to become predisposed to fibrosis development prior to initiation. This suggests that these …

Delineation Of Ascending Aortic Medial Degeneration Using Diffusion Tensor Imaging, Justin A. Ching-Johnson

Electronic Thesis and Dissertation Repository

Thoracic aortic aneurysms (TAAs) are a life-threatening dilation of the thoracic aorta that can lead to catastrophic dissection or rupture. In TAAs, the structure of the aortic wall is perturbed. Current imaging approaches assess lumen dimensions but lack the ability to delineate aortic wall architecture, a key determinant of aortic integrity. Diffusion tensor imaging (DTI) is an MRI modality which can reveal tissue microstructure through diffusion characteristics. In this thesis I investigated the potential for DTI to evaluate TAA architecture. A porcine model of aortic wall degeneration was developed, and DTI scans were performed on healthy and degenerated porcine ascending …

Validation Of Arterial Spin Labeling For Longitudinal Monitoring And Differential Diagnosis Of Frontotemporal Dementia, Tracy Ssali

Electronic Thesis and Dissertation Repository

Frontotemporal dementia (FTD) is a devastating neurodegenerative disease characterized by a rapid decline in behavioural, language, and motor abilities. Advances in the understanding of FTD genetics and pathophysiology, and the subsequent development of novel disease modifying treatments have highlighted the need for tools to assess their efficacy. While structural magnetic resonance imaging (MRI) and functional imaging with ¹⁸F-flurodeoxyglucose (FDG) positron emission tomography (PET) are used for clinical diagnosis, structural changes are subtle at the early stages and PET imaging is expensive and access limited. Given the coupling of cerebral blood flow (CBF) to energy metabolism, an attractive alternative is …

Rapid Recovery Of Cerebral Blood Content And Oxygenation In Adults From Time-Resolved Near-Infrared Spectroscopy, David J. F. Cohen

Electronic Thesis and Dissertation Repository

Patient neurological outcomes following cardiac surgery are improved when near-infrared spectroscopy (NIRS) is used to optimize intraoperative cerebral oxygen delivery. However, current NIRS analysis methods have difficulties monitoring adult brains due to contamination from the extracerebral layer (ECL).

The objective of this thesis is to develop a time-resolved (TR) NIRS data analysis method for monitoring adult cerebral oxygen saturation (ScO2) and total hemoglobin (HbT) by assuming the head is composed of two layers – the ECL and the brain. We tested the validity of this assumption using in silico data from an adult human head using two approaches; a few-wavelength, …

An Approach For The In-Vivo Characterization Of Brain And Heart Inflammation In Duchenne Muscular Dystrophy, Joanne Tang

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by dystrophin loss—notably within muscles and CNS neurons. DMD presents as cognitive weakness, progressive skeletal and cardiac muscle degeneration until pre-mature death from cardiac or respiratory failure. Innovative therapies improved life expectancy, but this is accompanied by increased late-onset heart failure and emergent cognitive degeneration. Thus, there is an increasing need to both better understand and track disease pathophysiology in the dystrophic heart and brain prior to onset of severe degenerative symptoms. Chronic inflammation is strongly associated with skeletal and cardiac muscle degeneration, however chronic neuroinflammation’s role is largely unknown in …

Ganglioside Detection From Formalin Fixed Human Brain Tissue Utilizing Maldi Imaging Mass Spectrometry, Aaron Harris

Electronic Thesis and Dissertation Repository

Matrix assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) is largely performed on fresh frozen tissue whereas clinical tissue samples stored long term are fixed in formalin, and the fixation process is thought to cause signal suppression for lipid molecules. Studies show that fresh frozen brain tissue sections washed with ammonium formate (AF) solution prior to matrix application in the MALDI-IMS procedure display an increase in signal intensity and sensitivity for lipid molecules while maintaining molecular spatial distribution. Work in this thesis compares MALDI data of ganglioside molecules from fresh frozen and post-fixed rat brain samples, and post-fixed human …

Investigating In Vivo Brain Metabolite Levels In Concussed Female Athletes And A Murine Model Of Repetitive Closed Head Injury, Amy L. Schranz

Electronic Thesis and Dissertation Repository

After a concussion there is a complex cascade of events, termed the neurometabolic cascade, that includes changes in ion flux, neurotransmission, and cellular energetics. How this pathophysiological process translates into cognitive deficits remains poorly understood. Magnetic resonance spectroscopy (MRS) provides a non-invasive technique that allows for the quantification of brain metabolites that are involved in these processes, including glutamate and glutamine, which are involved in neurotransmission. Moreover, female athletes are underrepresented in studies on concussion, limiting our knowledge and understanding of sex differences. The overall goal of this thesis was to examine metabolite changes using MRS in female athletes before …

The Effect Of Sepsis On Cerebral Microvascular Blood Flow, Laura Mawdsley, Mamadou Diop, Chris G. Ellis

Western Research Forum

Background: Sepsis is a dysregulated host response to infection that affects 18 000 000 people worldwide, and over 325 000 000 dollars are spent treating sepsis in Canada every year. One of the symptoms of severe sepsis is an altered mental state, which is accompanied with a measured decrease in oxygen levels in the skeletal muscle microvasculature. It is hypothesized that his altered mental state is due to a lack of oxygenated blood reaching the brain.

Hypothesis: After the onset of sepsis, microvascular cerebral blood flow and oxygen levels in the blood will decrease. Onset of decreased blood flow in …

A Randomized Controlled Trial Of A Modified Cystoscopy Technique, Khalil Hetou

Electronic Thesis and Dissertation Repository

Introduction

Pain, anxiety and embarrassment are well documented feelings in patients undergoing ambulatory diagnostic cystoscopy. In this study, we explored utilizing Peak-end theory in improving pain perception in patients undergoing diagnostic cystoscopy.

Materials and Methods

We conducted a randomized clinical trial at the London Health Sciences Center for patients undergoing an ambulatory diagnostic cystoscopy for the first time. Males and females as well as allocation ratios were 1:1. The control arm received a standard cystoscopy. In the intervention arm the cystoscope was left for additional 2 minutes without further manipulation in the bladder before scope removal. The primary outcome was …

7t Magnetic Resonance Spectroscopy Of Non-Lesional Temporal Lobe Epilepsy, John Robert Adams

Electronic Thesis and Dissertation Repository

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy, and one that is generally amenable to surgical treatment when surgery is necessary. Unfortunately, roughly 25-30% of the patient population have no visible lesions on clinical MRI scans. Without anatomical abnormalities to help guide surgical resection, the success of surgical treatment decreases substantially. However, metabolic abnormalities may exist that could allow for accurate localization of epileptic tissue in this cohort. Magnetic resonance spectroscopy (MRS) is a technique that can detect and measure the concentration of metabolically important molecules within tissue, giving insight into the underlying cellular metabolism.

In …

Determining The Detective Quantum Efficiency (Dqe) Of X-Ray Detectors In Clinical Environments, Terenz R. Escartin

Electronic Thesis and Dissertation Repository

According to Health Canada, dental and medical radiography accounts for more than 90% of total man-made radiation dose to the general population. Ensuring patients receive the health benefits of diagnostic x-ray imaging without use of higher radiation exposures requires knowledge and understanding of the detective quantum efficiency (DQE). Currently, the DQE is not measured in clinics because it requires specialized instrumentation and specific DQE-expertise to perform an accurate analysis. In this regard, the goals of this thesis were to: 1) address the limitations of measuring the DQE in clinical environments that affects the accuracy of the measurement; 2) develop and …

The Application Of Self-Administered Nutrition Screening Tools And Evaluations Of The Impact Of Malnutrition On Quality Of Life In Individuals With Head And Neck Cancer, Mark J. P. Lynch

Electronic Thesis and Dissertation Repository

Abstract

Background: Individuals with head and neck cancer (HNCa) are at an increased risk of malnutrition. Therefore, self-administered nutrition screens which attempt to address their nutritional concerns may yield benefits for treatment outcomes and quality of life (QOL).

Methods: 34 participants (26 men, 8 women) completed one demographic and two QOL surveys, two nutrition self-screening tools, a nutrition assessment and an ease-of-use questionnaire. Results of the screens were compared to those of the assessment, and relationships between QOL, nutrition status, and demographics were examined.

Results: 32.3% of participants were identified as nutritionally compromised. The sensitivity and specificity for the PG-SGA …

Evaluating Evolving Leukocyte Populations In Peripheral Blood Circulation Post-Concussion In A Human Longitudinal Analysis Of Female Athletes, Kevin A. Blackney

Electronic Thesis and Dissertation Repository

Concussions are generating increasing concern due to potential long-term neurological consequences. Currently there is no universally recognized diagnostic approach for concussion. I hypothesize that a signature temporal response of biomarkers of inflammation in systemic circulation will provide an objective diagnosis of concussion and could also be used to track patient recovery. The Western University women’s rugby team underwent blood draws at pre-season and post-season as a baseline evaluation, and players determined to have sustained a concussion underwent repeat blood analysis post-concussion. Blood samples were analyzed by flow cytometry to profile immune cell populations alongside accepted concussion assessments, and complete blood …

Design Of Radio-Frequency Arrays For Ultra-High Field Mri, Ian R O Connell

Electronic Thesis and Dissertation Repository

Magnetic Resonance Imaging (MRI) is an indispensable, non-invasive diagnostic tool for the assessment of disease and function. As an investigational device, MRI has found routine use in both basic science research and medicine for both human and non-human subjects.

Due to the potential increase in spatial resolution, signal-to-noise ratio (SNR), and the ability to exploit novel tissue contrasts, the main magnetic field strength of human MRI scanners has steadily increased since inception. Beginning in the early 1980’s, 0.15 T human MRI scanners have steadily risen in main magnetic field strength with ultra-high field (UHF) 8 T MRI systems deemed to …

T2 Relaxation Time In Men And Women Following Eccentric Elbow Flexor Exercise, Patrick A. Moull

Electronic Thesis and Dissertation Repository

Previous research suggests that estrogen exhibits a protective effect on skeletal muscle and may help curb the effects of induced damage. Eccentric (ECC) exercise has been shown to provide the greatest levels of exercise induced muscle damage (EIMD) and with indirect markers of muscle damage including decreases in strength, increased inflammation, and higher magnitudes of delayed onset muscle soreness (DOMS). Studies have shown that elevations of the T2 relaxation times of activated muscles coincide with these other indirect measures of muscle damage. The purpose of this study was to compare the effects of a high intensity ECC elbow flexor exercise …

Non-Invasive Quantification Of Alveolar Morphometry Measurements In Older Never-Smokers, Gregory A. Paulin

Electronic Thesis and Dissertation Repository

Diffusion-weighted noble gas pulmonary magnetic resonance imaging (MRI) provides in vivo images with a contrast uniquely sensitive to molecular displacement at cellular and sub-cellular length scales. We estimated the external airway radius (R) and internal airway radius (r) of the alveolar dimensions to evaluate potential differences in acinar duct morphometries in healthy older never-smokers and compared those with a group of ex-smokers. The acinar duct and alveolar MRI morphometry results were within the physiologically-valid range of parameters. Estimated values of internal (r) and external (R) airway radius as well as alveolar sheath (h) and …