Biomedical Engineering and Bioengineering Commons^™

Reconstruction Algorithms For Novel Joint Imaging Techniques In Pet, Homayoon Ranjbar

McKelvey School of Engineering Theses & Dissertations

Positron emission tomography (PET) is an important functional in vivo imaging modality with many clinical applications. Its enormously wide range of applications has made both research and industry combine it with other imaging modalities such as X-ray computed tomography (CT) or magnetic resonance imaging (MRI). The general purpose of this work is to study two cases in PET where the goal is to perform image reconstruction jointly on two data types.

The first case is the Beta-Gamma image reconstruction. Positron emitting isotopes, such as ¹¹C, ¹³N, and ¹⁸F, can be used to label molecules, and tracers, such …

Characterization Of Structural Dynamics Of The Human Head Using Magnetic Resonance Elastography, Andrew Arun Badachhape

McKelvey School of Engineering Theses & Dissertations

In traumatic brain injury (TBI), the skull-brain interface, composed of three meningeal layers: the dura mater, arachnoid mater, and pia mater, along with cerebrospinal fluid (CSF) between the layers, plays a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is a noninvasive imaging modality capable of providing in vivo estimates of tissue motion and material properties. The objective of this work is to augment human and phantom MRE studies to better characterize the mechanical contributions of the skull-brain interface to improve the parameterization and validation of computational models of TBI. Three specific aims …

Image Reconstruction Of The Speed Of Sound And Initial Pressure Distributions In Ultrasound Computed Tomography And Photoacoustic Computed Tomography, Thomas Paul Matthews

McKelvey School of Engineering Theses & Dissertations

Ultrasound computed tomography (USCT) and photoacoustic computed tomography (PACT) are two emerging imaging modalities that have a wide range of potential applications from pre-clinical small animal imaging to cancer screening in human subjects. USCT is typically employed to measure acoustic contrasts, including the speed of sound (SOS) distribution, while PACT typically measures optical contrasts or some related quantity such as the initial pressure distribution. Their complementary contrasts and similar implementations make USCT and PACT a natural fit for a hybrid imaging system. Still, much work remains to realize this promise. First, USCT image reconstruction methods based on the acoustic wave …

System Optimization And Iterative Image Reconstruction In Photoacoustic Computed Tomography For Breast Imaging, Yang Lou

McKelvey School of Engineering Theses & Dissertations

Photoacoustic computed tomography(PACT), also known as optoacoustic tomography (OAT), is an emerging imaging technique that has developed rapidly in recent years. The combination of the high optical contrast and the high acoustic resolution of this hybrid imaging technique makes it a promising candidate for human breast imaging, where conventional imaging techniques including X-ray mammography, B-mode ultrasound, and MRI suffer from low contrast, low specificity for certain breast types, and additional risks related to ionizing radiation. Though significant works have been done to push the frontier of PACT breast imaging, it is still challenging to successfully build a PACT breast imaging …

Photodynamic Therapy: Agents And Mechanisms, Rebecca Claire Gilson

McKelvey School of Engineering Theses & Dissertations

Despite enormous efforts, cancer remains a leading cause of morbidity and mortality world-wide. The main challenges currently facing cancer therapy include lack of adequate tumor targeting, failure to treat hypoxic tumor cells, and induction therapy resistant tumors. A solution to these limitations can be found in photodynamic therapy (PDT) which combines light and light activatable compounds, photosensitizers (PSs), to produce cytotoxic reactive oxygen species (ROS) to damage tumor tissue. This creates a spatiotemporal therapeutic effect, where cell damage only occurs at the intersection of the PS and light. PDT can treat tumors through unique mechanisms which reduce induction of tumor …