Medical Biophysics Commons^™

Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electron paramagnetic resonance (EPR), and its molecular imaging modality, is a powerful tool to noninvasively map various biological and chemical markers within objects of interest. Reliable data acquisition is a major impeding factor for longitudinal hands-off measurements. Measurements are especially challenging in biomedical applications, as live objects are not static. Frequent changes occur that require constant fine recalibration of the EPR detection system, called the resonator. To enable longitudinal imaging, a technology permitting automatic digital control of resonator coupling, tuning, and EPR data acquisition was developed. Automation was achieved through the utilization of a microcontroller and digital peripheral components such …

Repetitive Mild Traumatic Brain Injury In Mice Triggers A Slowly Developing Cascade Of Long-Term And Persistent Behavioral Deficits And Pathological Changes, Xiaoyun Xu, Matthew Cowan, Flavio Beraldo, Amy Schranz, Patrick Mccunn, Nicole Geremia, Zalman Brown, Maitray Patel, Karen L. Nygard, Reza Khazaee, Lihong Lu, Xingyu Liu, Michael J. Strong, Gregory A. Dekaban, Ravi Menon, Robert Bartha, Mark Daley, Haojie Mao, Vania Prado, Marco A.M. Prado, Lisa Saksida, Tim Bussey, Arthur Brown

Medical Biophysics Publications

We have previously reported long-term changes in the brains of non-concussed varsity rugby players using magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI) and functional magnetic imaging (fMRI). Others have reported cognitive deficits in contact sport athletes that have not met the diagnostic criteria for concussion. These results suggest that repetitive mild traumatic brain injuries (rmTBIs) that are not severe enough to meet the diagnostic threshold for concussion, produce long-term consequences. We sought to characterize the neuroimaging, cognitive, pathological and metabolomic changes in a mouse model of rmTBI. Using a closed-skull model of mTBI that when scaled to human leads …

Fev1 And Mri Ventilation Defect Reversibility In Asthma And Copd, Hana Serajeddini, Rachel L Eddy, Christopher Licskai, David G Mccormack, Grace Parraga

Medical Biophysics Publications

The underlying pathophysiological determinants of asthma and chronic obstructive pulmonary disease (COPD) are related in complex ways. Importantly however, post-bronchodilator FEV1- reversibility may occur in approximately 50% of COPD patients whilst epidemiological and magnetic-resonance-imaging (MRI) studies suggest that in asthmatics, FEV1-reversibility may diminish over time. As compared to patients with asthma or COPD alone, patients with coexisting asthma and COPD report worse clinical outcomes and increased healthcare costs and burden.

Pulmonary Xenon-129 Mri: New Opportunities To Unravel Enigmas In Respiratory Medicine, Rachel L Eddy, Grace Parraga

Medical Biophysics Publications

No abstract provided.

The Canadian Dementia Imaging Protocol: Harmonization Validity For Morphometry Measurements, Olivier Potvin, Isabelle Chouinard, Louis Dieumegarde, Robert Bartha, Pierre Bellec, D. Louis Collins, Maxime Descoteaux, Rick Hoge, Joel Ramirez, Christopher J.M. Scott, Eric E. Smith, Stephen C. Strother, Sandra E. Black, Simon Duchesne

Medical Biophysics Publications

© 2019 The Authors The harmonized Canadian Dementia Imaging Protocol (CDIP) has been developed to suit the needs of a number of co-occurring Canadian studies collecting data on brain changes across adulthood and neurodegeneration. In this study, we verify the impact of CDIP parameters compliance on total brain volume variance using 86 scans of the same individual acquired on various scanners. Data included planned data collection acquired within the Consortium pour l'identification précoce de la maladie Alzheimer - Québec (CIMA-Q) and Canadian Consortium on Neurodegeneration in Aging (CCNA) studies, as well as opportunistic data collection from various protocols. For images …

Development Of A Pulmonary Imaging Biomarker Pipeline For Phenotyping Of Chronic Lung Disease, Fumin Guo, Dante Capaldi, Miranda Kirby, Khadija Sheikh, Sarah Svenningsen, David G Mccormack, Aaron Fenster, Grace Parraga

Medical Biophysics Publications

We designed and generated pulmonary imaging biomarker pipelines to facilitate high-throughput research and point-of-care use in patients with chronic lung disease. Image processing modules and algorithm pipelines were embedded within a graphical user interface (based on the .NET framework) for pulmonary magnetic resonance imaging (MRI) and x-ray computed-tomography (CT) datasets. The software pipelines were generated using C++ and included: (1) inhaled

Pulmonary Abnormalities And Carotid Atherosclerosis In Ex-Smokers Without Airflow Limitation., Damien Pike, Miranda Kirby, Tamas J Lindenmaier, Khadija Sheikh, Casey E Neron, Daniel G Hackam, J David Spence, Aaron Fenster, Nigel A M Paterson, Don D Sin, Harvey O Coxson, David G Mccormack, Grace Parraga

Medical Biophysics Publications

Abstract It is well-established that COPD patients have a burden of vascular disease that cannot be fully-explained by smoking history but the mechanistic links between atherosclerosis and pulmonary disease in COPD patients are not well-understood. Moreover, in ex-smokers without symptoms or other evidence of COPD, subclinical pulmonary and vascular disease, although potentially present, has not been described or evaluated. Hence our aim was to use sensitive three-dimensional (3D) pulmonary and carotid imaging to quantify pulmonary airway/parenchyma abnormalities and atherosclerosis in ex-smokers without airflow limitation or symptoms consistent with COPD. We evaluated 61 subjects without airflow limitation including 34 never- (72 …

Tracking The Fate Of Stem Cell Implants With Fluorine-19 Mri., Jeffrey M Gaudet, Emeline J Ribot, Yuhua Chen, Kyle M Gilbert, Paula J Foster

Medical Biophysics Publications

BACKGROUND: In this study we used cellular magnetic resonance imaging (MRI) to detect mesenchymal stem cells (MSC) labeled with a Fluorine-19 (19F) agent. 19F-MRI offers unambiguous detection and in vivo quantification of labeled cells.

METHODS: We investigated two common stem cell transplant mouse models: an immune competent, syngeneic transplant model and an immune compromised, xenograft transplant model. 19F labelled stem cells were implanted intramuscularly into the hindlimb of healthy mice. The transplant was then monitored for up to 17 days using 19F-MRI, after which the tissue was excised for fluorescence microscopy and immunohistochemisty.

RESULTS: Immediately following transplantation, 19F-MRI quantification correlated …

Measurement Of The Vascular Input Function In Mice For Dce-Mri, Dustin K. Ragan

Dissertations and Theses (Open Access)

DCE-MRI is an important technique in the study of small animal cancer models because its sensitivity to vascular changes opens the possibility of quantitative assessment of early therapeutic response. However, extraction of physiologically descriptive parameters from DCE-MRI data relies upon measurement of the vascular input function (VIF), which represents the contrast agent concentration time course in the blood plasma. This is difficult in small animal models due to artifacts associated with partial volume, inflow enhancement, and the limited temporal resolution achievable with MR imaging. In this work, the development of a suite of techniques for high temporal resolution, artifact resistant …