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- Lung cancer (2)
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- Acute ischemic stroke (1)
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- Back pain (1)
- Blood-brain barrier (1)
- CT perfusion (1)
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- ECG Gating (1)
- Endplate defect classification (1)
- Endplate defect phenotypes (1)
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- Flattening filter free (FFF) (1)
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Articles 1 - 10 of 10
Full-Text Articles in Radiology
The Impact Of Simulated Image Acquisition Time Reduction On Image Quality And Parameters Of Myocardial Perfusion Imaging Using A Dedicated Cardiac Camera, Alireza Khatami
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 …
Vertebral Endplate Structural Defects: Measurement, Prevalence And Associated Factors, Aliyu Lawan
Vertebral Endplate Structural Defects: Measurement, Prevalence And Associated Factors, Aliyu Lawan
Electronic Thesis and Dissertation Repository
Objective: To synthesize current knowledge on the association of endplate structural defects (EPSD) with back pain (BP), improve EPSD measurement, and investigate EPSD prevalence, distribution, and association with age and body mass index (BMI).
Methods: In study 1, a systematic review was conducted on five databases for studies reporting on the association between EPSD and BP. Studies 2 and 3 used CTs and mCTs of 19 embalmed cadavers to examine the diagnostic accuracy of common EPSD assessment methods, and to develop and validate a novel method. Study 4 used the novel method on 200 adult males’ MRI to estimate EPSD …
Improving The Reliability And Accessibility Of Ct Perfusion Imaging In Acute Ischemic Stroke, Kevin J. Chung
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 …
Technical Adaptations For Cardiac Sodium Mri, Taylor L. Marcus
Technical Adaptations For Cardiac Sodium Mri, Taylor L. Marcus
Electronic Thesis and Dissertation Repository
Cardiac sodium (Na+) MRI has the potential to unveil relationships between chronic kidney disease (CKD) and cardiovascular disease (CVD). Unfortunately, this modality requires many technical adaptations before it’s possible to extract and compare image data between individuals. This study investigated whether cardiac electrocardiogram (ECG) gating could improve image quality, and whether a uniform phantom could increase signal uniformity if a surface coil is used to acquire the image. Healthy participants were imaged with a custom-built surface coil and 3.0-T MR system. Cardiac gated images presented with a decreased signal-to-noise ratio (SNR), but intensity correction significantly increased image signal …
Quantitative Mri And 3d-Printing For Monitoring Periprosthetic Joint Infection, Greg Hong
Quantitative Mri And 3d-Printing For Monitoring Periprosthetic Joint Infection, Greg Hong
Electronic Thesis and Dissertation Repository
Joint replacements are becoming increasingly commonplace with over 130,000 joint arthroplasties being performed annually in Canada. Although joint replacement surgery is highly successful, implants do occasionally fail and need to be replaced via costly and difficult revision surgery. Periprosthetic joint infection (PJI) has recently become the leading reason for revision of both hip and knee replacements, which is unfortunate because PJI is difficult to diagnose and treat effectively; diagnosis is made particularly difficult by the lack of established non-invasive (imaging) means of evaluating PJI. This thesis aims to demonstrate that magnetic resonance imaging (MRI) has potential for diagnosing and monitoring …
Optimizing Respiratory Gated Intensity Modulated Radiation Therapy Planning And Delivery Of Early-Stage Non-Small Cell Lung Cancer, Ilma Xhaferllari
Optimizing Respiratory Gated Intensity Modulated Radiation Therapy Planning And Delivery Of Early-Stage Non-Small Cell Lung Cancer, Ilma Xhaferllari
Electronic Thesis and Dissertation Repository
Stereotactic ablative body radiotherapy (SABR) is the standard of care for inoperable early-stage non-small cell lung cancer (NSCLC) patients. However, thoracic tumours are susceptible to respiratory motion and, if unaccounted for, can potentially lead to dosimetric uncertainties. Respiratory gating is one method that limits treatment delivery to portions of the respiratory cycle, but when combined with intensity-modulated radiotherapy (IMRT), requires rigorous verification. The goal of this thesis is to optimize respiratory gated IMRT treatment planning and develop image-guided strategies to verify the dose delivery for future early-stage NSCLC patients.
Retrospective treatment plans were generated for various IMRT delivery techniques, including …
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 …
The Impact Of Lateral Electron Disequilibrium On Stereotactic Body Radiation Therapy Of Lung Cancer, Brandon Disher
The Impact Of Lateral Electron Disequilibrium On Stereotactic Body Radiation Therapy Of Lung Cancer, Brandon Disher
Electronic Thesis and Dissertation Repository
Stereotactic Body Radiation Therapy (SBRT) is an effective treatment option for patients with inoperable early-stage lung cancer. SBRT uses online image-guidance technology [e.g. cone-beam CT (CBCT)] to focus small-fields of high energy x-rays onto a tumour to deliver ablative levels of radiation dose (e.g. 54 Gy) in a few treatment fractions (e.g. 3). For the combination of these treatment parameters and a low density lung, lateral electron disequilibrium (LED) can potentially occur, reducing lung and tumour doses. The goal of this thesis was to determine the impact of LED on stereotactic body radiation therapy for lung cancer.
The effect of …
Mri-Based Attenuation Correction In Emission Computed Tomography, Harry R. Marshall
Mri-Based Attenuation Correction In Emission Computed Tomography, Harry R. Marshall
Electronic Thesis and Dissertation Repository
The hybridization of magnetic resonance imaging (MRI) with positron emission tomography (PET) or single photon emission computed tomography (SPECT) enables the collection of an assortment of biological data in spatial and temporal register. However, both PET and SPECT are subject to photon attenuation, a process that degrades image quality and precludes quantification. To correct for the effects of attenuation, the spatial distribution of linear attenuation coefficients (μ-coefficients) within and about the patient must be available. Unfortunately, extracting μ-coefficients from MRI is non-trivial. In this thesis, I explore the problem of MRI-based attenuation correction (AC) in emission tomography.
In particular, I …
Hearts And Minds: Examining The Evolution Of The Egyptian Excerebration And Evisceration Traditions Through The Impact Mummy Database, Andrew D. Wade
Hearts And Minds: Examining The Evolution Of The Egyptian Excerebration And Evisceration Traditions Through The Impact Mummy Database, Andrew D. Wade
Electronic Thesis and Dissertation Repository
Egyptian mummification and funerary rituals were a transformative process, making the deceased a pure being; free of disease, injury, and disfigurements, as well as ethical and moral impurities. Consequently, the features of mummification available to specific categories of individuals hold social and ideological significance. This study refutes long-held classical stereotypes, particularly dogmatic class associations; demonstrates the apocryphal nature of universal heart retention; and expands on the purposes of excerebration and evisceration implied by synthetic and radiological analyses.
Features of the embalming traditions, specifically the variable excerebration and evisceration traditions, represented the Egyptian view of death. Fine-grain analyses, through primary imaging …