Medicine and Health Sciences Commons^™

Automatic Cardiac Mri Image Segmentation And Mesh Generation, Ziyuan Li

McKelvey School of Engineering Theses & Dissertations

Segmenting and reconstructing cardiac anatomical structures from magnetic resonance (MR) images is essential for the quantitative measurement and automatic diagnosis of cardiovascular diseases [1]. However, manual evaluation of the time-series cardiac MRI (CMRI) obtained during routine clinical care are laborious, inefficient, and tends to produce biased and non-reproducible results [2]. This thesis proposes an end-to-end pipeline for automatically segmenting short-axis (SAX) CMRI images and generating high-quality 2D and 3D meshes suitable for finite element analysis. The main advantage of our approach is that it can not only work as a stand-alone pipeline for the automatic CMR image segmentation and mesh …

Evaluation And Clinical Implementation Of A Dual-Energy Ct Stopping-Power Ratio Mapping Technique For Proton-Therapy Treatment Planning, Maria Jose Medrano Matamoros

McKelvey School of Engineering Theses & Dissertations

Proton radiotherapy has the potential to treat tumors with better conformal dose distribution than competing modalities when the rapid dose falloff at the end of the proton-beam range is correctly aligned to the edge of the clinical target volume (CTV). However, its clinical potential is dependent on the accurate localization of the Bragg-peak position from predicted stopping-power ratio maps. The method that is most commonly used in today’s clinical practice for predicting stopping-power ratio (SPR) consists of a stoichiometric calibrationtechnique based on single-energy CT (SECT) for direct estimation of patient-specific SPR distribution from vendor-reconstructed Hounsfield Unit (HU) images. Unfortunately, this …

Effect Of Ultrasound Pressure On The Distribution Of Bovine Serum Albumin Delivered By Focused Ultrasound-Mediated Blood-Brain Barrier Opening In Cleared Mouse Brains, Yajie Liu

McKelvey School of Engineering Theses & Dissertations

Most common diagnosis and therapeutic methods have low effectiveness when used on brain diseases. The key obstacle is that the blood-brain barrier (BBB) prevents most drugs from entering the brain. Some strategies have been developed to improve the efficiency of drug delivery crossing BBB. Among all these strategies, focused ultrasound-mediated BBB opening (FUS-BBB Opening) stands out since it is noninvasive and can be located to the target area. Detailed studies are required on the distribution of drugs delivered by FUS-BBB opening and the effects of FUS parameters on the distribution. This thesis proposes a pipeline involving tissue clearing and lightsheet …

Focused Ultrasound-Mediated Drug Delivery To The Brainstem, Dezhuang Ye

McKelvey School of Engineering Theses & Dissertations

Brainstem gliomas are tumors that occur in the brainstem, the brain region that connects the brain to the spinal cord and controls vital body functions. The critical anatomic location of the brainstem precludes surgical intervention and limits the use of invasive therapeutic techniques. Moreover, the frequently intact blood-brain barrier (BBB) of most brainstem gliomas prevents therapeutic agents from reaching the diseased site. The currently available techniques for brain drug delivery are either invasive (e.g., convection-enhanced delivery) or lack targeting to the diseased site (e.g., intranasal brain drug delivery). Novel techniques that can noninvasively overcome the BBB are critically needed for …

Multi-Dimensional Extension Of The Alternating Minimization Algorithm In X-Ray Computed Tomography, Jingwei Lu

McKelvey School of Engineering Theses & Dissertations

X-ray computed tomography (CT) is an important and effective tool in medical and industrial imaging applications. The state-of-the-art methods to reconstruct CT images have had great development but also face challenges. This dissertation derives novel algorithms to reduce bias and metal artifacts in a wide variety of imaging modalities and increase performance in low-dose scenarios. The most widely available CT systems still use the single-energy CT (SECT), which is good at showing the anatomic structure of the patient body. However, in SECT image reconstruction, energy-related information is lost. In applications like radiation treatment planning and dose prediction, accurate energy-related information …

Multi-Dimensional Extension Of The Alternating Minimization Algorithm In X-Ray Computed Tomography, Jingwei Lu

McKelvey School of Engineering Theses & Dissertations

X-ray computed tomography (CT) is an important and effective tool in medical and industrial

imaging applications. The state-of-the-art methods to reconstruct CT images have had

great development but also face challenges. This dissertation derives novel algorithms to

reduce bias and metal artifacts in a wide variety of imaging modalities and increase performance

in low-dose scenarios.

The most widely available CT systems still use the single-energy CT (SECT), which is

good at showing the anatomic structure of the patient body. However, in SECT image

reconstruction, energy-related information is lost. In applications like radiation treatment

planning and dose prediction, accurate energy-related information …

Differential Estimation Of Audiograms Using Gaussian Process Active Model Selection, Trevor Larsen

McKelvey School of Engineering Theses & Dissertations

Classical methods for psychometric function estimation either require excessive resources to perform, as in the method of constants, or produce only a low resolution approximation of the target psychometric function, as in adaptive staircase or up-down procedures. This thesis makes two primary contributions to the estimation of the audiogram, a clinically relevant psychometric function estimated by querying a patient’s for audibility of a collection of tones. First, it covers the implementation of a Gaussian process model for learning an audiogram using another audiogram as a prior belief to speed up the learning procedure. Second, it implements a use case of …

The Effect Of Mechanical Agitator Geometry On Catheter Directed Thrombectomy, Sanghun Alex Lee

McKelvey School of Engineering Theses & Dissertations

Venous thromboembolism (VTE) is a vascular disease in which a blood clot forms inside of a vein, most often deep in the legs, groin, or arm. Two types of VTE exist, deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT occurs when a clot in a deep vein forms, risking embolism and causing swelling as the clot obstructs blood flow. An embolism occurs when a part or all the thrombus breaks off and travels in the circulation, getting lodged in the lungs. A pulmonary embolism is a very serious medical condition and can be fatal if not treated immediately. Current …

Ls301 Fluorescence-Guided Photodynamic Therapy Of Brain Cancer Using Ppix Photosensitizer, Haini Zhang

McKelvey School of Engineering Theses & Dissertations

Incomplete brain tumor removal always causes neurologic deficit, disease recurrence and high mortality. Protoporphyrin IX (PpIX) accumulated in glioma cells with exogenous 5-aminolevulinic acid (5-ALA) serves as contrast agent for fluorescence-guided surgery and as well as acts as a photosensitizer for photodynamic therapy (PDT). However, the accurate tumor delineation using PpIX is limited by autofluorescence and superficial penetration depth. LS301 is a tumor-targeted near-infrared (NIR) contrast agent developed in our lab which allows deeper tumor imaging and avoids autofluorescence. My project aims to investigate whether LS301 can improve PpIX mediated PDT and tumor removal surgery. We have demonstrated co-localization of …