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Full-Text Articles in Biomedical Engineering and Bioengineering

Characterization Of Histological Changes In The Microvasculature Of Rat Skeletal Muscle After Spinal Cord Injury, Sally Lin Oct 2016

Characterization Of Histological Changes In The Microvasculature Of Rat Skeletal Muscle After Spinal Cord Injury, Sally Lin

Master's Theses (2009 -)

The purpose of this study was to determine whether there are histological changes in the microvasculature of rat skeletal muscle following chronic spinal cord injury both above and below the level of injury. This study is important because microvascular structure likely impacts muscle performance and cardiovascular health. To the best of our knowledge, this is the only study to investigate microvascular structure within rat skeletal muscle after spinal cord injury. We hypothesized structural remodeling would occur in both the myofibers and microvasculature, which would then manifest in differences in myofiber cross sectional area and microvascular diameter, wall thickness, wall to ...


Diffusion Imaging In The Rat Cervical Spinal Cord, Elizabeth Zakszewski, Brian D. Schmit, Shekar N. Kurpad, Matthew D. Budde Apr 2015

Diffusion Imaging In The Rat Cervical Spinal Cord, Elizabeth Zakszewski, Brian D. Schmit, Shekar N. Kurpad, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Magnetic resonance imaging (MRI) is the state of the art approach for assessing the status of the spinal cord noninvasively, and can be used as a diagnostic and prognostic tool in cases of disease or injury. Diffusion weighted imaging (DWI), is sensitive to the thermal motion of water molecules and allows for inferences of tissue microstructure. This report describes a protocol to acquire and analyze DWI of the rat cervical spinal cord on a small-bore animal system. It demonstrates an imaging setup for the live anesthetized animal and recommends a DWI acquisition protocol for high-quality imaging, which includes stabilization of ...


Ex Vivo Diffusion Tensor Imaging Of Spinal Cord Injury In Rats Of Varying Degrees Of Severity, Michael Jirjis, Shekar N. Kurpad, Brian D. Schmit Sep 2013

Ex Vivo Diffusion Tensor Imaging Of Spinal Cord Injury In Rats Of Varying Degrees Of Severity, Michael Jirjis, Shekar N. Kurpad, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

The aim of this study was to characterize magnetic resonance diffusion tensor imaging (DTI) in proximal regions of the spinal cord following a thoracic spinal cord injury (SCI). Sprague–Dawley rats (n = 40) were administered a control, mild, moderate, or severe contusion injury at the T8 vertebral level. Six direction diffusion weighted images (DWIs) were collected ex vivo along the length of the spinal cord, with an echo/repetition time of 31.6 ms/14 sec and b = 500 sec/mm2. Diffusion metrics were correlated to hindlimb motor function. Significant differences were found for whole cord region of interest (ROI ...


Diffusion Tensor Imaging Of The Central Nervous System Following An Injury To The Spinal Cord And Cell Transplant, Michael Jirjis Jan 2013

Diffusion Tensor Imaging Of The Central Nervous System Following An Injury To The Spinal Cord And Cell Transplant, Michael Jirjis

Dissertations (1934 -)

The purpose of this dissertation research was to characterize the use of magnetic resonance diffusion tensor imaging (DTI) as a diagnostic and prognostic tool in understanding the changes that occur throughout the spinal cord and brain following a spinal cord injury (SCI) and following stem cell transplant. The diffusion of water inside the nervous system is dramatically altered around the lesion site following a traumatic SCI. However, following damage to the spinal cord, little is known about the diffusion characteristics away from an injury and even less is understood about DTI's sensitivity to structural changes that occur following regenerative ...


Imaging Radiation Pneumonitis In A Rat Model Of A Radiological Terrorism Incident, Robert C. Molthen, Qingping Wu, Gary S. Krenz, Meetha Medhora, Elizabeth R. Jacobs, John E. Moulder Feb 2009

Imaging Radiation Pneumonitis In A Rat Model Of A Radiological Terrorism Incident, Robert C. Molthen, Qingping Wu, Gary S. Krenz, Meetha Medhora, Elizabeth R. Jacobs, John E. Moulder

Biomedical Engineering Faculty Research and Publications

We have developed a rat model of single, sub-lethal thoracic irradiation. Our irradiation protocol is considered representative of exposures near the detonation site of a dirty bomb or small nuclear device. The model is being used to investigate techniques for identifying, triaging and treating possible victims. In addition to physiological markers of right ventricular hypertrophy, pulmonary vascular resistance, and arterial distensibility, we present two methods for quantifying microvascular density. We used methods including microfocal X-ray imaging to investigate changes in lung structure/function resulting from radiation exposure. Radiation pneumonitis is a complication in subjects receiving thoracic irradiation. A radiographic hallmark ...


Quantification Of Bronchial Circulation Perfusion In Rats, Christian Wieholt, Robert C. Molthen, Steven Thomas Haworth, David L. Roerig, Christopher A. Dawson, Anne V. Clough Feb 2004

Quantification Of Bronchial Circulation Perfusion In Rats, Christian Wieholt, Robert C. Molthen, Steven Thomas Haworth, David L. Roerig, Christopher A. Dawson, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

The bronchial circulation is thought to be the primary blood supply for pulmonary carcinomas. Thus, we have developed a method for imaging and quantifying changes in perfusion in the rat lung due to development of the bronchial circulation. A dual-modality micro-CT/SPECT system was used to detect change in perfusion in two groups of rats: controls and those with a surgically occluded left pulmonary artery. Both groups were imaged following injections on separate days i) 2mCi of Tc99m labeled macroaggregated albumin (MAA) into the left carotid artery (IA) and ii) a similar injection into the femoral vein (IV). The IA ...


Spect Imaging Of Pulmonary Blood Flow In A Rat, Christian Wieholt, Robert C. Molthen, Roger H. Johnson, Christopher A. Dawson, Anne V. Clough Feb 2003

Spect Imaging Of Pulmonary Blood Flow In A Rat, Christian Wieholt, Robert C. Molthen, Roger H. Johnson, Christopher A. Dawson, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Small animal imaging is experiencing rapid development due to its importance in providing high-throughput phenotypic data for functional genomics studies. We have developed a single photon emission computed tomography (SPECT) system to image the pulmonary perfusion distribution in the rat. A standard gamma camera, equipped with a pinhole collimator, was used to acquire SPECT projection images at 40 sec/view of the rat thorax following injection of Tc99m labeled albumin that accumulated in the rat's lungs. A voxel-driven, ordered-subset expectation maximization reconstruction was implemented. Following SPECT imaging, the rat was imaged using micro-CT with Feldkamp conebeam reconstruction. The two ...


Estimation Of Pulmonary Arterial Volume Changes In The Normal And Hypertensive Fawn-Hooded Rat From 3d Micro-Ct Data, Robert C. Molthen, Christian Wieholt, Steven Thomas Haworth, Christopher A. Dawson Feb 2002

Estimation Of Pulmonary Arterial Volume Changes In The Normal And Hypertensive Fawn-Hooded Rat From 3d Micro-Ct Data, Robert C. Molthen, Christian Wieholt, Steven Thomas Haworth, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

In the study of pulmonary vascular remodeling, much can be learned from observing the morphological changes undergone in the pulmonary arteries of the rat lung when exposed to chronic hypoxia or other challenges which elicit a remodeling response. Remodeling effects include thickening of vessel walls, and loss of wall compliance. Morphometric data can be used to localize the hemodynamic and functional consequences. We developed a CT imaging method for measuring the pulmonary arterial tree over a range of pressures in rat lungs. X-ray micro-focal isotropic volumetric imaging of the arterial tree in the intact rat lung provides detailed information on ...