Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

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 …

Improving The Reliability And Accessibility Of Ct Perfusion Imaging In Acute Ischemic Stroke, Kevin J. Chung

Electronic Thesis and Dissertation Repository

CT perfusion (CTP) imaging is a validated treatment decision support tool in acute ischemic stroke. Automated analysis of CTP cerebral blood flow (CBF) and Tmax maps produces estimates of ischemic core and penumbra volumes used to determine target mismatch profiles for treatment. However, availability and utilization of CTP is low due to diagnostic variability between CTP software and technical, logistical, and radiation dose considerations that may limit its routine adoption. The objective of this doctoral research was to improve the reliability and accessibility of CTP by (1) improving diagnostic agreement between CTP software, (2) enabling perfusion imaging with standard acute …

An Evaluation Of A Deep Learning Approach For Radiation Dose Reduction In 18f-Fdg Pet/Mri Pediatric Epilepsy Imaging, Confidence Raymond

Electronic Thesis and Dissertation Repository

Epilepsy is a degenerative brain disease characterized by abruption of neural activities that result in seizures. The onset of epileptic seizures are usually from a primary source - the epileptogenic foci (EF) which could be distributed to nearby neurons and tissues. Accurate localization of EF is critical in epilepsy cases where drug treatment has failed, and surgery is indicated to resect the EF to alleviate seizure. Typically, hybrid positron emission tomography (PET) and computed tomography (CT) imaging are performed to functionally localize the EF in drug-resistant epilepsy for surgical planning when anatomical abnormalities representing the EF cannot be identified on …

Identification Of Dna Methylation Episignatures For Classification And Phenotype/Genotype Correlation In Mendelian Neurodevelopmental Disorders, John Reilly

Electronic Thesis and Dissertation Repository

ABSTRACT: Diagnosis for neurodevelopmental disorders poses numerous challenges, related to the lack of specific findings and limited understanding of clinical impact of the majority of genetic variation. Epigenomics mechanisms involve chemical modifications in DNA that involve a range of cellular mechanisms. DNA methylation is an epigenetic mechanism involving addition and removal of methyl groups to cytosine residues. These methylation signals form episignatures; patterns of methylation that can be used as biomarkers capable of differentiating neurodevelopmental disorders. EpiSigns have enabled molecular diagnosis of a number of genetic conditions, classification of variants of unknown significance, and provided insights into the pathophysiology of …

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 …

Novel Imaging Tools Reveal The Dynamics Of The Myocardial Growth Hormone Secretagogue Receptor In Heart Disease And Heart Failure, Rebecca Sullivan

Electronic Thesis and Dissertation Repository

Heart disease (HD) is the leading cause of mortality worldwide. Currently, diagnosis is based on clinical features, imaging, and circulating cardiac biomarkers. Cardiac imaging technologies, such as echocardiography and cardiac magnetic resonance imaging (cMRI), enable the non-invasive detection of changes in heart function. Although these modalities can detect changes in structure and anatomy, it is usually at later stages, where prevention may not be possible. In conjunction with imaging, circulating biomarkers of heart failure (HF), notably B-type natriuretic peptide (BNP) and cardiac troponin I and T, can be detected with increased levels in the blood. These biomarkers are associated with …

Optimizing Preprocessing Of Fmri Data To Maximize Correspondence Of Functional Anatomy Across Individuals, Nargess Ghazaleh

Electronic Thesis and Dissertation Repository

In movie-activation fMRI, intersubject correlation (ISC) indicates a functional correspondence across viewers. Brains di↵er in shape; spatial normalization and smoothing enhance inter-subject functional overlap. We compare three normalization methods and six smoothing levels to discover which method yields the best functional overlap, indexed by ISC. This is key to optimizing data analysis in clinical studies using movie-activation fMRI in future. In a 3T scanner, 44 healthy subjects watched an 8-min movie. Both normalization and smoothing a↵ected the strength and extent of the ISC. ISC values were more robust for ANTs and DARTELthanforSPM12andwere(asymptotically)thestrongestat12mmsmoothing. When image data are preprocessed with high-dimensional volumetric …

Epilepsy Risk Among Survivors Of Intensive Care Unit Hospitalization For Sepsis, Tresah C. Antaya, Britney N. Allen, Lucie Richard, Salimah Z. Shariff, Gustavo Saposnik, Jorge Burneo

Neuroepidemiology Research Unit Project Summaries

Research Summary: Key Findings

• 407 (0.28%) patients developed epilepsy within 2 years of their ICU discharge, 103 (25.3%) of whom were exposed to sepsis.
• Sepsis survivors were significantly more likely to develop epilepsy, relative to non-septic ICU survivors.
• Among sepsis survivors, epilepsy risk increased with age and was higher among those with chronic kidney disease.

Voice Analysis With Iphones: A Low Cost Experimental Solution, Benjamin Van Der Woerd

Electronic Thesis and Dissertation Repository

Background:

Acoustic voice analysis requires a resource intensive setup, including a soundproof booth. This project evaluates smartphone microphone and recording environment impacts on voice sample collection for acoustic voice analysis. A proprietary analysis algorithm is presented for validation.

Methods:

Microphone and recording environment were evaluated using previously collected voice samples presented in four conditions to test two microphones and two recording environments. Prospective samples were used to test the proprietary algorithm, whereby samples were analyzed using this and Praat.

Results:

Microphone and recording environment had small, clinically unimportant impacts on most measurements. The proprietary algorithm reliably analyzed sustained vowels, with …

Impact Of Diagnostic Terminology On Parental Attitudes Toward Concussion And Brain Injury, Naomi Sanderson

Electronic Thesis and Dissertation Repository

Although some have argued that the terms concussion and mild traumatic brain injury (mTBI) should not be used interchangeably, any differences between the diagnoses are subtle. In this study, we recruited 98 individuals through Amazon Mechanical Turk who self-identified as having children between the ages of 13 and 18 (inclusive). Participants were asked questions about a hypothetical injury to their child, related to symptoms, participation in school and physical activity, and recovery prognosis. Roughly half (n = 51) were asked these questions in reference to a “concussion”, and the remainder (n = 47) were asked questions in reference to an …

Cell-Free Dna Release During Programmed Cell Death In Ischemia Reperfusion Injury, Alexander Dionne, Anthony M. Jevnikar, Zhu-Xu Zhang

Western Research Forum

Transplantation is invariably associated with acute allograft injury caused by ischemia reperfusion injury (IRI). This injury causes cells of the allograft to undergo various forms of programmed cell death including apoptosis and necroptosis. During programmed cell death, immunogenic molecules are released from cells, one of which is cell-free DNA (cfDNA). We hypothesize that cfDNA is released by microvascular endothelial cells (MVECs) during programmed cell death of IRI and that cfDNA acts as both a biomarker for cellular injury as well as a biologically active molecule capable of amplifying inflammation and organ injury.

Our results indicate that cfDNA is released by …

The Risk Of New-Onset Epilepsy And Refractory Epilepsy In Older Adult Stroke Survivors, Jorge G. Burneo, Tresah C. Antaya, Britney N. Allen, Andrea Belisle, Salimah Z. Shariff, Gustavo Saposnik

Neuroepidemiology Research Unit Project Summaries

Research Summary: Key Findings

• Stroke is a common cause of epilepsy in older adults, but little is known about stroke-related epilepsy or its outcomes in this population.
• 1.1% of older adult stroke survivors developed epilepsy in this study, of whom 12.9% developed refractory epilepsy, indicating that this population is particularly responsive to treatment.
• Over 85% of deaths in this population are not due to stroke or epilepsy.

Investigating The Pathogenesis Of Staphylococcus Aureus In Periprosthetic Joint Infections, Santiago L. Iglesias

Electronic Thesis and Dissertation Repository

The most challenging complication after total joint replacement is the periprosthetic joint infection (PJI). Staphylococcus aureus is a commensal bacterium and a human pathogen. It is responsible for more than half of the PJI. We demonstrated that synovial fluid has antimicrobial properties against S. aureus and the iron restriction is one of the mechanisms used for the host to prevent bacterial growth, and is even able to increase killing of S. aureus. We have shown a clear role of transferrin as a restrictive factor in synovial fluid that functions by iron starving the bacteria and sensitizing them to killing …

Hepcidin-Mediated Iron Regulation In P19 Cells Is Detectable By Mri, Kobra Alizadeh Pourbouyeh

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) can be used to track cellular activities in the body using iron-based contrast agents. However, intrinsic cellular iron handling mechanisms may also influence the detection of magnetic resonance (MR) contrast. For instance, inflammation involves downregulation of iron export in macrophages by the hormone hepcidin, due to degradation of the iron export protein, ferroportin (Fpn). We examined the effect of hepcidin on iron regulation and MR transverse relaxation rates in multi-potent P19 cells, which display high iron export activity, similar to macrophages. In response to varying conditions of iron supplementation, our results showed similar Fpn expression in …

E-Visits For Early Post-Operative Visits Following Orthopaedic Surgery Can They Add Efficiency Without Sacrificing Effectiveness, William G. Jeffery

Electronic Thesis and Dissertation Repository

We asked 217 sport surgery and 135 total knee arthroplasty (TKA) patients to complete a questionnaire (e-Visit) before attending their two and six-week post-operative appointment. Our primary objective was to use the questions asked of patients prior to their appointment to develop a model that could be used as web-based e-Visit to predict early post-operative adverse events. Gold standard comparison was the surgeon’s opinion as to the presence or absence of an event at follow-up. Secondary objective was evaluation of a simplified model. We found good area under the curve (AUC) statistics (0.76 (95% CI 0.69 - 0.84) and 0.80 …

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 …

A Novel Hybrid Imaging System To Aid In Surgical Decision Making, Lawrence Yip, Madeleine Van De Kleut, Ivan Kosik, Astrid Chamson-Reig, Jeffrey Jl Carson

Western Research Forum

Background:

Breast cancer accounts for 25% of all cancer cases among women. In breast-conserving surgery, a common treatment, the tumour is excised with a healthy tissue margin. However, detection of the margin can be difficult. Current techniques to guide excision are often insufficient, and re-excision can occur up to 25% of the time.

Methods:

Photoacoustic imaging is a hybrid imaging modality that combines the advantages of optical imaging and ultrasound while using safe non-ionizing light. This project involves the development of a novel imaging system with a new scanner design to overcome common limitations and provide images to aid in …

Discovery Of Novel Diagnostic Biomarkers On Prostate Tumor Microparticles For Discriminating Between Low And High Risk Prostate Cancer And Improving Prostate Cancer Screening, Sabine Brett

Electronic Thesis and Dissertation Repository

There are few protein-based biomarkers to accurately distinguish between patients with low risk prostate cancer from those with high risk disease in a non-invasive manner. Prostate specific antigen (PSA) is used for clinical follow-up of prostate cancer; however, it is not effective as a screening tool. As a result, many men with non-life threatening disease having to undergo unnecessary and painful biopsies. Therefore, there is a dire need for minimally invasive platforms for monitoring patients with clinically significant prostate cancer. Prostate cell microparticles (PCMPs) released by prostate epithelial cells into plasma are a potential source of biomarkers specific for prostate …

Development Of Anatomical And Functional Magnetic Resonance Imaging Measures Of Alzheimer Disease, Samaneh Kazemifar

Electronic Thesis and Dissertation Repository

Alzheimer disease is considered to be a progressive neurodegenerative condition, clinically characterized by cognitive dysfunction and memory impairments. Incorporating imaging biomarkers in the early diagnosis and monitoring of disease progression is increasingly important in the evaluation of novel treatments. The purpose of the work in this thesis was to develop and evaluate novel structural and functional biomarkers of disease to improve Alzheimer disease diagnosis and treatment monitoring. Our overarching hypothesis is that magnetic resonance imaging methods that sensitively measure brain structure and functional impairment have the potential to identify people with Alzheimer’s disease prior to the onset of cognitive decline. …

Feasibility Of Using Arterial Spin Labeling For Detecting Longitudinal Changes In Cerebral Blood Flow, Tracy Ssali

Electronic Thesis and Dissertation Repository

The ability of the perfusion MRI technique, arterial spin labeling (ASL), to quantify cerebral blood flow (CBF) makes it attractive for longitudinal studies of changes in brain function, such as those related to chronic pain. However, ASL's poor spatial resolution makes image alignment between sessions difficult, leading to increased variance and greater Type-I errors. In addition, variability due to differences in basal blood flow between sessions and confounding effects such as the arterial transit time (ATT) have the potential to reduce reproducibility over time. The focus of this thesis is to investigate the ability of ASL to detect long-term changes …

Hyperpolarized 129xe Magnetic Resonance Imaging Of Radiation-Induced Lung Injury, Ozkan Doganay

Electronic Thesis and Dissertation Repository

Lung cancer is the largest contributor to cancer-related mortality worldwide. Only 20% of stage III non-small cell lung cancer patients survive after 5-years post radiation therapy (RT). Although RT is an important treatment modality for lung cancer, it is limited by Radiation-Induced Lung Injury (RILI). RILI develops in two phases: (i) the early phase (days-weeks) referred to radiation pneumonitis (RP), and (ii) the late phase (months). There is a strong interest in early detection of RP using imaging to improve outcomes of RT for lung cancer. This thesis describes a promising approach based on ¹²⁹Xe gas as a contrast …

Inter-Rater Reliability Of The Mckenzie System Of Mechanical Diagnosis And Therapy In The Examination Of The Knee, Sean Willis

Electronic Thesis and Dissertation Repository

Objective: The purpose of this thesis was to investigate the inter-rater reliability of the McKenzie System of Mechanical Diagnosis and Therapy (MDT) when classifying patients with musculoskeletal knee pain using clinical vignettes. Methods: This study was divided into two phases. First, ten clinicians experienced in the use of MDT were randomly recruited to write a total of 60 clinical vignettes based upon the initial assessment of past patients with knee pain. Second, six different MDT raters were recruited to rate 53 selected vignettes and reliability was determined using Fleiss Kappa. Results: There was “substantial agreement” among six MDT raters …

Interpretation Of Mutations, Expression, Copy Number In Somatic Breast Cancer: Implications For Metastasis And Chemotherapy, Stephanie Dorman

Electronic Thesis and Dissertation Repository

Breast cancer (BC) patient management has been transformed over the last two decades due to the development and application of genome-wide technologies. The vast amounts of data generated by these assays, however, create new challenges for accurate and comprehensive analysis and interpretation. This thesis describes novel methods for fluorescence in-situ hybridization (FISH), array comparative genomic hybridization (aCGH), and next generation DNA- and RNA-sequencing, to improve upon current approaches used for these technologies. An ab initio algorithm was implemented to identify genomic intervals of single copy and highly divergent repetitive sequences that were applied to FISH and aCGH probe design. FISH …

Evaluating Human Performance For Image-Guided Surgical Tasks, Matthew Kenneth Kramers

Electronic Thesis and Dissertation Repository

The following work focuses on the objective evaluation of human performance for two different interventional tasks; targeted prostate biopsy tasks using a tracked biopsy device, and external ventricular drain placement tasks using a mobile-based augmented reality device for visualization and guidance. In both tasks, a human performance methodology was utilized which respects the trade-off between speed and accuracy for users conducting a series of targeting tasks using each device. This work outlines the development and application of performance evaluation methods using these devices, as well as details regarding the implementation of the mobile AR application. It was determined that the …

Obtaining A Diagnosis Of Fetal Alcohol Spectrum Disorder: Experiences Of Caregivers And Professionals, Erica R. Lundberg

Electronic Thesis and Dissertation Repository

The current study describes the lived experiences of stakeholders in a community-based fetal alcohol spectrum disorders assessment clinic. A qualitative methodology was used. Five participants, one caregiver and four professionals, were interviewed about their experiences. Six themes emerged from this process including: clinic organization: systemic strengths and challenges; attitudes and approach: laying the foundation; beyond yes or no: assessment and diagnosis; the moment of truth: delivering the diagnosis; outcomes: what happens after the diagnosis?; what does the future hold? next steps and needs. These themes formed a sequential story-telling of participant experience. Study results are critiqued and practical implications are …

An Evaluation Of The Frankfort Mandibular Plane Angle Bisector (Fmab) Wits Appraisal In The Assessment Of Anteroposterior Jaw Relationships, Natalie Swoboda

Electronic Thesis and Dissertation Repository

An accurate anteroposterior measurement of jaw relationships is essential in orthodontic diagnosis and treatment planning. The purpose of this longitudinal study was to establish a new cephalometric Wits appraisal using a bisector of the mandibular plane angle, named the Frankfort Mandibular Plane Angle Bisector (FMAB). The FMAB was used to assess the sagittal jaw relationship in a sample of Class I individuals, and compare this measurement to the ANB angle and the Wits appraisal using the Maxillomandibular Bisector (MMB).

The data were collected from pre-treatment (T0), immediate post-treatment (T1) and two year post-retention (T2) lateral cephalograms of 61 male and …

Image Quality Of Energy-Dependent Approaches For X-Ray Angiography, Jesse Evan Tanguay

Electronic Thesis and Dissertation Repository

Digital subtraction angiography (DSA) is an x-ray-based imaging method widely used for diagnosis and treatment of patients with vascular disease. This technique uses subtraction of images acquired before and after injection of an iodinated contrast agent to generate iodine-specific images. While it is extremely successful at imaging structures that are near-stationary over a period of several seconds, motion artifacts can result in poor image quality with uncooperative patients and DSA is rarely used for coronary applications.

Alternative methods of generating iodine-specific images with reduced motion artifacts might exploit the energy-dependence of x-ray attenuation in a patient. This could be performed …

Peptide-Mediated Targeting Of Angiogenesis For Molecular Imaging And Treatment Of Cancer, Choi-Fong Cho

Electronic Thesis and Dissertation Repository

The development of screening approaches to identify novel affinity ligands has paved the way for a new generation of molecular targeted nanomedicines. To identify novel targeting ligands, several studies have demonstrated the advantages in screening one-bead-one-compound (OBOC) libraries. Conventional methods typically bias the display of the target protein to ligands during the screening process. We have developed an unbiased multiplex ‘beads on a bead’ strategy to isolate, characterize, and validate high affinity ligands from OBOC libraries. In addition, due to the advantages associated with screening OBOC libraries directly against living cells, we sought to combine cell-based screen methods with automated …

Diagnostic Validity Of Physical Examination Maneuvers And Patient Reported History For Shoulder Pathology, Lyndsay Somerville

Electronic Thesis and Dissertation Repository

Shoulder pain and disability can pose a diagnostic challenge for clinicians owing to the numerous etiologies than can exist and the potential for multiple disorders to co-exist. There are an abundance of physical examination maneuvers available to clinicians to utilize in their clinical decision making. Additionally the patient history may be an important diagnostic tool in patients with shoulder pathology. The evidence in support of most clinical tests is weak or absent and only a few studies have formally assessed the measurement properties of history findings. The purpose of this study is to determine the diagnostic validity of physical examination …

Durand Et Al 2012 Supplemental Figures, M. Durand, Svetlana V. Komarova, Ajay Bhargava, Keying Li, Cara Fiorino, Osama Maria, Noushin Nabavi, Morris Manolson, Rene Harrison, S. Jeffrey Dixon, Stephen Sims, Marcin Mizianty, Lukasz Kurgan, Sonia Haroun, Gilles Boire, Maria Lucena-Fernandes, Artur De Brum-Fernandes

Physiology and Pharmacology Publications

Objective. Our objective was to compare the osteoclastogenic capacity of peripheral blood mononuclear cells (PBMCs) from patients with osteoarthritis (OA) to that of PBMCs from self-reported normal individuals.

Methods. PBMCs from 140 patients with OA and 45 healthy donors were assayed for CD14⁺ expression and induced to differentiate into osteoclasts (OCs) over 3 weeks in vitro. We assessed the number of the OCs, their resorptive activity, OC apoptosis, and expression of the following cytokine receptors: receptor activator of nuclear factor κB (RANK), interleukin-1 receptor type I (IL-1R1) and IL-1R2. A ridge logistic regression classifier was developed …