Medicine and Health Sciences Commons^™

Examining The Association Between Brain Mri Measures At 7 Tesla And Cognition Following Covid-19 Infection, Helma Heidari

Electronic Thesis and Dissertation Repository

The long-term neuropsychological, cognitive, and neurobiological effects of the severe acute respiratory syndrome (SARS-CoV-2) in survivors with milder symptoms are still poorly understood. In this thesis we evaluated cognitive and psychological changes approximately five weeks after a wide range of symptoms in COVID-19 illness and determined whether advanced diffusion magnetic resonance imaging measures within subcortical brain structures of the limbic system were related to neurological, respiratory, psychiatric, and gastric symptoms experienced during the acute phase of illness. Cognitive and neuropsychological evaluations were performed in 45 participants who experienced neurological symptoms during the acute phase of COVID-19 illness. Participants also underwent …

Extended Functional Connectivity Of Convergent Structural Alterations Among Individuals With Ptsd: A Neuroimaging Meta-Analysis, Brianna S. Pankey, Michael C. Riedel, Isis Cowan, Jessica E. Bartley, Rosario Pintos Lobo, Lauren D. Hill-Bowen, Taylor Sato, Erica D. Musser, Matthew T. Sutherland, Angela R. Laird

Psychology Faculty Publications

Background: Post-traumatic stress disorder (PTSD) is a debilitating disorder defined by the onset of intrusive, avoidant, negative cognitive or affective, and/or hyperarousal symptoms after witnessing or experiencing a traumatic event. Previous voxel-based morphometry studies have provided insight into structural brain alterations associated with PTSD with notable heterogeneity across these studies. Furthermore, how structural alterations may be associated with brain function, as measured by task-free and task-based functional connectivity, remains to be elucidated.

Methods: Using emergent meta-analytic techniques, we sought to first identify a consensus of structural alterations in PTSD using the anatomical likelihood estimation (ALE) approach. Next, we generated functional …

Integrated Multiparametric Radiomics And Informatics System For Characterizing Breast Tumor Characteristics With The Oncotypedx Gene Assay, Michael A. Jacobs, Christopher B. Umbricht, Vishwa S. Parekh, Riham H. El Khouli, Leslie Cope, Katarzyna J. Macura, Susan Harvey, Antonio C. Wolff

Radiology Faculty Publications

Optimal use of multiparametric magnetic resonance imaging (mpMRI) can identify key MRI parameters and provide unique tissue signatures defining phenotypes of breast cancer. We have developed and implemented a new machine-learning informatic system, termed Informatics Radiomics Integration System (IRIS) that integrates clinical variables, derived from imaging and electronic medical health records (EHR) with multiparametric radiomics (mpRad) for identifying potential risk of local or systemic recurrence in breast cancer patients. We tested the model in patients (n = 80) who had Estrogen Receptor positive disease and underwent OncotypeDX gene testing, radiomic analysis, and breast mpMRI. The IRIS method was trained …

Epstein Barr Virus-Immortalizedｂlymphocytes Exacerbate Experimental Autoimmune Encephalomyelitis In Xenograft Mice, Pascal Polepole, Alison Bartenslager, Yutong Liu, Thomas M. Petro, Samodha C. Fernando, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Multiple sclerosis (MS) is the most common autoimmune disorder affecting the central nervous system. Epstein-Barr virus (EBV) is a causative agent for infectious mononucleosis (IM) that is associated with MS pathogenesis. However, the exact mechanism by which EBV, specifically in IM, increases the risk for MS remains unknown. EBV immortalizes primary B lymphocytes in vitro and causes excessive B lymphocyte proliferation in IM in vivo. In asymptomatic carriers, EBV-infected B lymphocytes still proliferate to certain degrees, the process of which is tightly controlled by the host immune systems. Experimental autoimmune encephalomyelitis (EAE) mimics key features of MS in humans …

Epstein Barr Virus-Immortalizedｂlymphocytes Exacerbate Experimental Autoimmune Encephalomyelitis In Xenograft Mice, Pascal Polepole, Alison Bartenslager, Yutong Liu, Thomas M. Petro, Samodha C. Fernando, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Multiple sclerosis (MS) is the most common autoimmune disorder affecting the central nervous system. Epstein-Barr virus (EBV) is a causative agent for infectious mononucleosis (IM) that is associated with MS pathogenesis. However, the exact mechanism by which EBV, specifically in IM, increases the risk for MS remains unknown. EBV immortalizes primary B lymphocytes in vitro and causes excessive B lymphocyte proliferation in IM in vivo. In asymptomatic carriers, EBV-infected B lymphocytes still proliferate to certain degrees, the process of which is tightly controlled by the host immune systems. Experimental autoimmune encephalomyelitis (EAE) mimics key features of MS in humans and …

Defining The Border Of The Subthalamic Nucleus For Deep Brain Stimulation: A Proposed Model Using The Symmetrical Sigmoid Curve Function, Anthony M.T Chau, Angela Jacques, Christopher R. Lind

IHR Papers and Journal Articles

Background: The subthalamic nucleus (STN) is an important target during deep brain stimulation (DBS). Accurate lead placement is integral to achieving satisfactory clinical outcomes; however, the STN remains a structure whose visualization is highly variable with borders often difficult to define. We aimed to develop an objective method of evaluating the visibility of the STN on preoperative magnetic resonance imaging (MRI) to standardize future comparative assessments between imaging protocols and patient-specific parameters.

Methods: An imaging study of 64 prospectively collected patients undergoing bilateral DBS of the STN for various movement disorders was performed with institutional approval. MRI scans were acquired …

Does An Acute Achilles Tendon Rupture Become A Patient's Achilles Heel In The Long-Term?, Michaela Cm Khan

Electronic Thesis and Dissertation Repository

It is unknown if deficits in the involved limb following acute Achilles tendon rupture (AATR) persist in the long-term, or differ between patients treated operatively or non-operatively. This study investigated 43 patients 15±1 years post-AATR from a previous randomized controlled trial (RCT) that compared operative and non-operative treatment. Structural characteristics in the Achilles tendon and surrounding musculature were assessed using magnetic resonance imaging. We also performed physical examinations and evaluated performance-based and patient-reported outcomes. Overall, there were substantial differences between the involved and uninvolved limbs in most outcomes. Some outcomes improved over time from the initial RCT to the final …

Developmental And Sex Modulated Neurological Alterations In Autism Spectrum Disorder, Azeezat Azeez

Dissertations

Autism Spectrum Disorder (ASD) was first described in 1943 by Dr. Leo Kranner in a case study published in The Nervous Child. It is a neurodevelopment disorder, with a range of clinical symptoms. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), used by clinicians to diagnose mental disorders, a child needs to have persistent social deficits, language impairments, and repetitive behaviors, that cannot be explained by neurological damage or intellectual disability. It is known that children diagnosed with ASD are often are developmentally delayed therefore alterations in the typical developmental trajectory should be a major factor in …

Quantitatively Studying Tissue Damage In Multiple Sclerosis Using Gradient Recalled Echo Mri Sequences, Biao Xiang

Arts & Sciences Electronic Theses and Dissertations

Multiple Sclerosis (MS) is an unpredictable, often disabling disease of the central nervous system (CNS) that disrupts the flow of information within the brain, and between the brain the body. MS is the most common progressive neurologic disease of young adults, affecting approximately 2.3 million people worldwide. It is estimated that more than 700,000 individuals are affected by MS in United States. While MS has been studied for decades, the cause of it is still not definite and a fully effective treatment for MS is not yet available. Magnetic resonance imaging (MRI) has been used extensively in MS diagnosis and …

Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau

Electronic Thesis and Dissertation Repository

Stereotactic neurosurgery is a subspecialty within neurosurgery concerned with accurate targeting of brain structures. Deep brain stimulation (DBS) is a specific type of stereotaxy in which electrodes are implanted in deep brain structures. It has proven therapeutic efficacy in Parkinson’s disease and Essential Tremor, but with an expanding number of indications under evaluation including Alzheimer’s disease, depression, epilepsy, and obesity, many more Canadians with chronic health conditions may benefit. Accurate surgical targeting is crucial with millimeter deviations resulting in unwanted side effects including muscle contractions, or worse, vessel injury. Lack of adequate visualization of surgical targets with conventional lower field …

Diagnosis Of Postretinal Blindness Caused By Intracranial Disease In Three Dogs, Joon Young Kim

Turkish Journal of Veterinary & Animal Sciences

In this report, we provide clinical information on the diagnosis of postretinal blindness in veterinary ophthalmology. We have diagnosed three dogs with postretinal blindness (bilateral in one case and in the left eye in two cases). The electroretinogram results were normal and the optic axis was relatively clear in all cases. Our findings indicate that the reason for the blindness in these dogs was an intracranial lesion. Fundus photography did not reveal any significant changes, except in the optic disc. A normal optic disc, an optic disc that appeared to be smaller than that in the other eye, and a …

Efficacy Of A Platelet-Rich Plasma Injection For The Treatment Of Proximal Hamstring Tendinopathy: A Pilot Study, Gavin M. Levy, Phil Lucas, Nigel Hope

Sciences Papers and Journal Articles

Objectives: To determine the efficacy of an ultrasound-guided platelet-rich plasma (PRP) injection in the treatment of patients with proximal hamstring tendinopathy (PHT).

Design: Pilot prospective cohort study

Methods: Administration of a single PRP injection under ultrasound guidance to 29 patients with PHT confirmed on magnetic resonance imaging (MRI). Pain, function and sporting activity were measured via the Victorian Institute of Sport Assessment-Proximal Hamstring Tendons (VISA-H) questionnaire, administered before injection and at 8-weeks follow-up.

Results: The study sample consisted of 22 females and 7 males with a mean age of 45.2 years (95% CI40.8–49.5). When comparing pre-injection VISA-H scores (mean: 43.90; …

The Brain Imaging Data Structure, A Format For Organizing And Describing Outputs Of Neuroimaging Experiments, Krzysztof Gorgolewski, Tibor Auer, Vince Calhoun, R Cameron Craddock, Samir Das, Eugene Duff, Guillaume Flandin, Tristan Glatard, Yaroslav Halchenko

Dartmouth Scholarship

The development of magnetic resonance imaging (MRI) techniques has defined modern neuroimaging. Since its inception, tens of thousands of studies using techniques such as functional MRI and diffusion weighted imaging have allowed for the non-invasive study of the brain. Despite the fact that MRI is routinely used to obtain data for neuroscience research, there has been no widely adopted standard for organizing and describing the data collected in an imaging experiment. This renders sharing and reusing data (within or between labs) difficult if not impossible and unnecessarily complicates the application of automatic pipelines and quality assurance protocols. To solve this …

In Ovo Serial Skeletal Muscle Diffusion Tractography Of The Developing Chick Embryo Using Dti: Feasibility And Correlation With Histology, Zien Zhou, Zachary Delproposto, Lianming Wu, Jianrong Xu, Jia Hua, Yan Zhou, Yongquan Ye, Zishu Zhang, Jiani Hu, E Mark Haacke

Yan Zhou 周彦文档

Abstract Background Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length. Results From 84 …

Belief About Nicotine Selectively Modulates Value And Reward Prediction Error Signals In Smokers, Xiaosi Gu, Terry Lohrenz, Ramiro Salas, Philip R. Baldwin, Alireza Soltani

Dartmouth Scholarship

Little is known about how prior beliefs impact biophysically described processes in the presence of neuroactive drugs, which presents a profound challenge to the understanding of the mechanisms and treatments of addiction. We engineered smokers' prior beliefs about the presence of nicotine in a cigarette smoked before a functional magnetic resonance imaging session where subjects carried out a sequential choice task. Using a model-based approach, we show that smokers' beliefs about nicotine specifically modulated learning signals (value and reward prediction error) defined by a computational model of mesolimbic dopamine systems. Belief of "no nicotine in cigarette" (compared with "nicotine in …

Low-Field Magnetic Resonance Anatomic Features Of The Neonatalfoal Thorax: An Ex Vivo Study, Alberto Arencibia, José Ángel Sandoval, Francisco Gil, José Raduán Jaber, Diego Blanco, Andrés Diz, José María Vázquez

Turkish Journal of Veterinary & Animal Sciences

The purpose of this study was to describe the normal appearance of the bony and soft tissue structures of the thorax of neonatal foals by low-field magnetic resonance imaging (MRI) and the use of anatomical dissections and gross sections. Three purebred Spanish neonatal foals that died for medical reasons unrelated to thoracic disease were used to obtain T1- and T2-weighted MR images using a magnet of 0.2 Tesla. Anatomic structures on the MR images were evaluated according to characteristics of signal intensity of the different organic tissues. The bones, different associated muscles, diaphragm, trachea, main bronchi, lungs, esophagus, heart chambers, …

Heart Performance Of Lambs And Its Relation To Muscle Volume And Body Surface, Róbert Romvári, Csaba Hancz, Péter Horn, Zsolt Petrási, András Szabó, Dávid Mezöszentgyörgyi, Imre Repa

Turkish Journal of Veterinary & Animal Sciences

Electrocardiography-gated dynamic magnetic resonance imaging (MRI) methodology was developed for the in vivo examination of sheep heart characteristics. By combining noninvasive determination of skeletal muscle mass, we studied the relationship between total body skeletal muscle content and heart performance. Measurements were carried out on male Merino lambs using 1.5 T field strength equipment. Average left ventricular volumes were determined and stroke volume was estimated during image postprocessing. Ejection fraction was calculated (73 ± 1.8%) and the cardiac output (CO) value was estimated (2.75 ± 0.16 L/min). After measuring left ventricular wall thickness, contraction values were determined at the septum (62%), …

Data Sharing In Neuroimaging Research, Jean-Baptiste Poline, Janis L. Breeze, Satrajit Ghosh, Krzysztof Gorgolewski, Yaroslav O. Halchenko

Dartmouth Scholarship

Significant resources around the world have been invested in neuroimaging studies of brain function and disease. Easier access to this large body of work should have profound impact on research in cognitive neuroscience and psychiatry, leading to advances in the diagnosis and treatment of psychiatric and neurological disease. A trend toward increased sharing of neuroimaging data has emerged in recent years. Nevertheless, a number of barriers continue to impede momentum. Many researchers and institutions remain uncertain about how to share data or lack the tools and expertise to participate in data sharing. The use of electronic data capture (EDC) methods …

In Ovo Serial Skeletal Muscle Diffusion Tractography Of The Developing Chick Embryo Using Dti: Feasibility And Correlation With Histology, Zien Zhou, Zachary Delproposto, Lianming Wu, Jianrong Xu, Jia Hua, Yan Zhou, Yongquan Ye, Zishu Zhang, Jiani Hu, E Mark Haacke

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length.

Results

From 84 …

Resting State Default-Mode Network Connectivity In Early Depression Using A Seed Region-Of-Interest Analysis: Decreased Connectivity With Caudate Nucleus, Robyn Bluhm, Peter Williamson, Ruth Lanius, Jean Théberge, Maria Densmore, Robert Bartha, Richard Neufeld, Elizabeth Osuch

Philosophy Faculty Publications

Aim: Reports on resting brain activity in healthy controls have described a default-mode network (DMN) and important differences in DMN connectivity have emerged for several psychiatric conditions. No study to date, however, has investigated resting-state DMN in relatively early depression before years of medication treatment. The objective of the present study was, therefore, to investigate the DMN in patients seeking help from specialized mental health services for the first time for symptoms of depression.

Methods: Fourteen depressed subjects and 15 matched controls were scanned using 4-T functional magnetic resonance imaging while resting with eyes closed. All but one subject was …

Magnetic Resonance Imaging Findings Of Intracranial Tumors In Dogs: A Review Of 26 Cases, Ömer Beşalti, Y. Si̇nan Şi̇ri̇n, Zeynep Pekcan, Gonca Erbaş

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to report the magnetic resonance imaging (MRI) findings of intracranial tumors in 26 dogs. The medical records of dogs admitted to the Department of Surgery, Faculty of Veterinary Medicine, Ankara University for central nervous system disorders were reviewed, and dogs with intracranial tumors that were diagnosed with MRI between November 1997 and June 2006 were included in the study. MR images were obtained as T1 weighted (T1W), T2 weighted (T2W), and contrast enhanced T1 weighted (following Gd-DTPA administration) in the transverse, coronal (dorsal), and sagittal planes. The following features were evaluated in order to …

Description Of A Poorly Differentiated Carcinoma Within The Brainstem Of A White Whale (Delphinapterus Leucas) From Magnetic Resonance Images And Histological Analysis, Sam H. Ridgway, Lori Marino, T. P. Lipscomb

Veterinary Science and Medicine Collection

In this study we used magnetic resonance imaging (MRI) to investigate neuroanatomical structure in the brain of a white whale (Delphinapterus leucas) that died from a large tumor within the brainstem. This specimen was also compared with a normal white whale brain using MRI. MRI scans of the white whale specimen show how the tumor deformed surrounding brain structure. Histopathological analysis indicated a poorly differentiated carcinoma of uncertain origin. These analyses demonstrate the usefulness of supplementing histological analyses of pathology with studies of gross morphology facilitated by MRI.

Anatomy And Three-Dimensional Reconstructions Of The Brain Of A Bottlenose Dolphin (Tursiops Truncatus) From Magnetic Resonance Images, Lori Marino, Keith D. Sudheimer, Timothy L. Murphy, Kristina K. Davis, D. Ann Pabst, William A. Mclellan, James K. Rilling, John I. Johnson

Veterinary Science and Medicine Collection

Cetacean (dolphin, whale, and porpoise) brains are among the least studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Magnetic resonance imaging offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Furthermore, internal structures can be analyzed in their precise anatomic positions, which is difficult to accomplish after the spatial distortions often accompanying histological processing. In this study, images of the brain of an adult bottlenose dolphin, Tursiops truncatus, were scanned in the coronal plane at 148 antero-posterior levels. From these scans …