Biomedical Engineering and Bioengineering Commons^™

Segmentation Of Intracranial Structures From Noncontrast Ct Images With Deep Learning, Evan Porter

Wayne State University Dissertations

Presented in this work is an investigation of the application of artificially intelligent algorithms, namely deep learning, to generate segmentations for the application in functional avoidance radiotherapy treatment planning. Specific applications of deep learning for functional avoidance include generating hippocampus segmentations from computed tomography (CT) images and generating synthetic pulmonary perfusion images from four-dimensional CT (4DCT).A single institution dataset of 390 patients treated with Gamma Knife stereotactic radiosurgery was created. From these patients, the hippocampus was manually segmented on the high-resolution MR image and used for the development of the data processing methodology and model testing. It was determined that …

Assessing Midbrain Abnormalities In Parkinson’S Disease Using Magnetic Resonance Imaging, Kiarash Ghassaban

Wayne State University Dissertations

Diagnosing early-stage Parkinson’s disease (PD) and its manifestations is still a clinical challenge. Previous imaging studies using iron, neuromelanin (NM) and the Nigrosome-1 (N1) measures in the substantia nigra (SN) by themselves have been unable to provide sufficiently high diagnostic performance for these methods to be adopted clinically. In this dissertation, we start by studying idiopathic PD patients at their intermediate stages of the disease to evaluate the role of global and regional iron in the major deep gray matter nuclei. Then, we only focus on the NM complex in the midbrain and how neuronal loss interact with iron overload …

Development Of Photoacoustic Tomographic Systems For Brain Hemorrhage Detection, Karl Kratkiewicz

Wayne State University Dissertations

Preterm neonates (age) and/or with low birth weight (

Photoacoustic imaging (PAI) is an imaging modality which derives its contrast from differences in optical absorption coefficients of tissue through laser irradiation and acoustic detection. Therefore, PAI derives its signal directly from optical absorbers such as blood; the critical component in a hemorrhage. We discuss operation and processing methods of our Verasonics Vantage system. We then investigate thermal safety of PAI in mouse model for various laser pulse repetitions rates and illumination duration. We then develop two photoacoustic tomographic systems for eventual translation to clinic for hemorrhage detection. One system being …

Incorporating Cardiac Substructures Into Radiation Therapy For Improved Cardiac Sparing, Eric Daniel Morris

Wayne State University Dissertations

Growing evidence suggests that radiation therapy (RT) doses to the heart and cardiac substructures (CS) are strongly linked to cardiac toxicities, though only the heart is considered clinically. This work aimed to utilize the superior soft-tissue contrast of magnetic resonance (MR) to segment CS, quantify uncertainties in their position, assess their effect on treatment planning and an MR-guided environment.

Automatic substructure segmentation of 12 CS was completed using a novel hybrid MR/computed tomography (CT) atlas method and was improved upon using a 3-dimensional neural network (U-Net) from deep learning. Intra-fraction motion due to respiration was then quantified. The inter-fraction setup …

Utilizing Immunopet To Measure Tumor Response To Treatment In Breast Cancer, Brooke Mcknight

Wayne State University Dissertations

With a broad spectrum of therapies available for treating breast cancer, the need for personalized medicine tailoring the cure according to phenotype is evident. Such an approach may be fully realized with the development of quantitative imaging technologies for disease detection, staging and diagnosis, without increasing patient burden. Immuno-positron emission tomography (PET) combines the targeted specificity of antibodies with the sensitivity of PET for whole body imaging by targeting molecular features amplified in lesions. ImmunoPET probes targeting different antigens and their utility to measure response to treatment were explored. 89Zr-trastuzumab was employed as a surrogate readout of Src inhibition after …

Study Of Mri Signal In The Presence Of Discrete Spherical Magnetic Particles, Paul Kokeny

Wayne State University Dissertations

Simulating signal behavior in Magnetic Resonance imaging (MRI) is often a necessary step in being able to understand how signal relates to certain physiological parameters. One such parameter of interest in the body is magnetic susceptibility since it is related to iron content. The bulk magnetic susceptibility of an object is a property that describes how magnetized it becomes when placed in an external magnetic field. When the bulk susceptibility of an object arises from the presence of discrete magnetic inclusions, the MRI phase signal inside the object can no longer be determined analytically by assuming it has a continuous …

Pet Imaging Of Early Therapeutic Response In Solid Tumors, Stephanie J. Blocker

Wayne State University Dissertations

An important pillar of precision medicine for oncology is the ability to identify patients who respond to treatment early into their therapy. Positron emission tomography (PET) allows physicians and researchers to measure changes in tumor behavior prior to noticeable differences in morphology.

Objective: Determine the utility of multiple tracers for PET in assessing early changes in tumor activity that result from treatment.

Methods: Two tracers for PET were studied. 64Cu-labeled liposomes were used to assess changes in liposome delivery two solid colon tumors early into treatment with bevacizumab (Bev). 18F-FMAU thymidine analog (1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)thymine), was utilized to detect early response to …

Europium(Ii)-Containing Complexes For Responsive Magnetic Resonance Imaging, Levi Alexander Ekanger

Wayne State University Dissertations

The research projects described in this dissertation are focused on studying the oxidation of EuII-containing complexes within the context of responsive MRI. Prior to this research, EuII had not been explored within the context of oxidation-responsive MRI nor had the use of this ion been reported in vivo. The results of these studies enable predictions about the oxidation-responsive behavior of EuII-containing complexes in vitro and in vivo.

The EuII-containing cryptate 1.33 was used to evaluate EuII-based positive contrast enhancement after intravenous, intraperitoneal, and subcutaneous injections. The transitory behavior of the positive contrast enhancement correlated with reported levels of oxygenation and …

X-Ray Beam Characteristics And Radiation Dose Deposition To Soft Tissue From Fluoroscopic X-Ray Beams Incorporating Copper Filtration, Kevin Arthur Wunderle

Wayne State University Dissertations

Purpose: This work investigated several topics related to dosimetry in soft tissue from fluoroscopic X-ray beams; first, it investigated the X-ray beam spectra and air kerma rates available for clinical use on state-of-the-art fluoroscopes using spectral (copper [Cu]) filtration; second, it investigated the fluoroscopic X-ray beam characteristics of first half-value layer (HVL), second HVL, homogeneity coefficients (HCs), and backscatter factors (BSFs) across the full range of available beam qualities; and third, it investigated the energy dependence of kerma-area-product (KAP)-meters measuring the radiation output of the fluoroscope. Materials and Methods: A state-of-the-art Siemens Artis Zee fluoroscope was operated in the service …

Quantitative Assessment Of Brain Iron Content As A Function Of Age Using Magnetic Resonance Imaging, Kiarash Ghassaban

Wayne State University Theses

As the most abundant transition metal in the brain, iron is known to play a key role in a variety of functional and cellular processes. Recent in vivo and post-mortem studies have shown that the levels of iron deposition in the brain, particularly in deep gray matter nuclei, vary as a function of age. On the other hand, elevated iron has also been associated with some neurodegenerative diseases such as Multiple Sclerosis (MS) and Parkinson’s disease (PD) among others.

Magnetic Resonance Imaging (MRI) is a widely used non-invasive and non-ionizing imaging modality which is sensitive to magnetic properties of materials …

Toward Magnetic Resonance Only Treatment Planning: Distortion Mitigation And Image-Guided Radiation Therapy Validation, Ryan Glen Price

Wayne State University Dissertations

While MR-only treatment planning has shown promise, there are still several well-known challenges that are currently limiting widespread clinical implementation.

Firstly, MR images are affected by both patient-induced and system-level geometric distortions that can significantly degrade treatment planning accuracy. . In addition, the availability of comprehensive distortion analysis software is currently limited. Also while many groups have been working toward a synthetic CT solution, further study is needed on the implementation of synCTs as the reference datasets for linac-based image-guided radiation therapy (IGRT) to help determine their robustness in an MR-only workflow.

A 36×43×2 cm3 phantom with 255 known landmarks …

Frequency Domain Ultrasound Waveform Tomography Breast Imaging, Gursharan Singh Sandhu

Wayne State University Dissertations

Ultrasound tomography is an emerging modality for imaging breast tissue for the detection of disease. Using the principles of full waveform inversion, high-resolution quantitative sound speed and attenuation maps of the breast can be created. In this thesis, we introduce some basic principles of imaging breast disease and the formalism of sound wave propagation. We present numerical methods to model acoustic wave propagation as well methods to solve the corresponding inverse problem. Numerical simulations of sound speed and attenuation reconstructions are used to assess the efficacy of the algorithm. A careful review of the preprocessing techniques needed for the successful …

Quantifying Magnetic Moments And Susceptibilities Of Small Cylindrical And Spherical Objects In Mri, Ching-Yi Hsieh

Wayne State University Dissertations

Purpose: The purpose of this PhD work is to develop a method for accurately quantifying effective magnetic moments and susceptibility of either cylindrical or spherical-like small objects from magnetic resonance imaging (MRI). A standard 3D gradient echo sequence with only one echo time is intended for our approach to measure the effective magnetic moment of a given object of interest. For the quantification of the susceptibility in the cylindrical objects at different orientations, a standard 3D gradient echo sequence with only one or two echo times is needed.

Methods: Our method is to sum over complex MR signals around the …

Visual Exploration And Information Analytics Of High-Dimensional Medical Images, Darshan Pai

Wayne State University Dissertations

Data visualization has transformed how we analyze increasingly large and complex data sets. Advanced visual tools logically represent data in a way that communicates the most important information inherent within it and culminate the analysis with an insightful conclusion. Automated analysis disciplines - such as data mining, machine learning, and statistics - have traditionally been the most dominant fields for data analysis. It has been complemented with a near-ubiquitous adoption of specialized hardware and software environments that handle the storage, retrieval, and pre- and postprocessing of digital data. The addition of interactive visualization tools allows an active human participant in …

The Role Of Tissue Sound Speed As A Surrogate Marker Of Breast Density, Mark Sak

Wayne State University Dissertations

Breast density is one of the strongest predictors of breast cancer risk as women with the densest breasts have a three- to five-fold increase in risk compared to women with the least dense breasts. Breast density is currently measured by using mammography, the current gold standard for breast imaging. There are many shortcomings to using mammography to measure breast density, including the use of ionizing radiation. Ultrasound tomography (UST) does not use ionizing radiation and can create tomographic breast sound speed images. These sound speed images are useful because breast density is proportional to sound speed. The purpose of this …

Compressed Sensing And Joint Acquisition Techniques In Mri, Rouhollah Hamtaei

Wayne State University Theses

The relatively long scan times in Magnetic Resonance Imaging (MRI) limits some clinical applications and the ability to collect more information in a reasonable period of time. Practically, 3D imaging requires longer acquisitions which can lead to a reduction in image quality due to motion artifacts, patient discomfort, increased costs to the healthcare system and loss of profit to the imaging center. The emphasis in reducing scan time has been to a large degree through using limited k-space data acquisition and special reconstruction techniques. Among these approaches are data extrapolation methods such as "constrained reconstruction" techniques, data interpolation methods such …

Application Of Magnetic Resonance Imaging To Understanding The Pathogenesis Of The X-Linked Leukodystrophy Pelizaeus-Merzbacher Disease, Jeremy Jerome Laukka

Wayne State University Dissertations

Myelin is a multilamellar membrane structure surrounding axons in both the CNS and PNS that facilitates nerve conduction. In the CNS, myelin is synthesized by oligodendrocytes, while in the PNS, myelin is synthesized by Schwann cells. In the CNS, Proteolipid protein 1 (PLP1), an integral membrane protein, is the major protein component of myelin, constituting ~50% of myelin protein. Mutations of the PLP1 gene in man cause a spectrum of neurological disease, ranging from the severe Pelizaeus-Merzbacher disease (PMD), that typically begins during infancy with nystagmus, seizures and hypotonia and evolves into spastic quadriparesis, cognitive impairment and ataxia, to ¡¥pure¡¦ …