Dissertations / Theses on the topic 'Brain imaging'
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Liu, Arthur K. (Arthur Kuang-Chung). "Spatiotemporal brain imaging." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8963.
Full textIncludes bibliographical references.
Understanding how the human brain works, in both health and disease, requires data with both high spatial and temporal resolution. This thesis develops and applies a spatiotemporal neuroimaging method. I describe a linear estimation inverse approach, which is a method for the combination of functional magnetic resonance imaging (fMRI) with electroencephalography (EEG) and magnetoencephalography (MEG). fMRI provides millimeter spatial resolution, while EEG and MEG provide millisecond temporal resolution. The thesis is divided into two broad sections: Monte Carlo modeling studies and experimental studies. Improvements to both the bioelectromagnetic forward and inverse solutions are demonstrated. Through modeling studies, I characterize the accuracy of the method with and without functional and anatomic constraints, the effects of various model mis-specifications, and as a function of EEG/MEG sensor configuration. I describe a noise sensitivity normalization to the traditional linear estimation operator that improves the point spread function (a measure of spatial resolution), increases the spatial homogeneity of the point spread, and allows interpretation of the localization in terms of a statistical measure (F-statistic). Using experimentally generated current dipoles implanted an epilepsy patient, I examine the accuracy of both a realistic and spherical EEG head model. This experimental data demonstrates the improved accuracy of the realistic head model, and gives us confidence in using this realistic head model for EEG source localization. The optimized and validated forward and inverse methods are then applied to a variety of empirical measurements. First, the combined multi modality imaging approach is used to simultaneous EEG/fMRI measurements of a visual stimulus, demonstrating the feasibility of measuring and localizing simultaneously acquired electric potential and hemodynamic measurements. Second, combined MEG/fMRI measurements are used to analyze the spatiotemporal characteristics of a cortical network that is responsive to visual motion coherency. Finally, in epilepsy patients, I compare the non-invasive MEG localization of interictal spikes with verification from invasive recordings and surgical results. These studies, in both normal volunteers and patients, clearly demonstrate the utility, accuracy, and power of the combined use of fMRI, EEG and MEG. The tools demonstrated here provide "real time movies" of the human brain at work during a given task or behavior. This information is required to develop computational models of how the human brain/mind works.
by ARthur K. Lui.
Ph.D.
Paolani, Giulia. "Brain perfusion imaging techniques." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Find full textLawrie, Stephen MacGregor. "Brain imaging in schizophrenia." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/21353.
Full textWitzel, Thomas Ph D. Massachusetts Institute of Technology. "Methods for functional brain imaging." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68459.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
Magnetic resonance imaging (MRI) has demonstrated the potential for non-invasive mapping of structure and function (fMRI) in the human brain. In this thesis, we propose a series of methodological developments towards improved fMRI of auditory processes. First, the inefficiency of standard fMRI that acquires brain volumes one slice at a time is addressed. The proposed single-shot method is capable, for the first time, of imaging the entire brain in a single-acquisition while still maintaining adequate spatial resolution for fMRI. This method dramatically increases the temporal resolution of fMRI (20 fold) and improves sampling efficiency as well as the ability to discriminate against detrimental physiological noise. To accomplish this it exploits highly accelerated parallel imaging techniques and MRI signal detection with a large number of coil elements. We then address a major problem in the application of fMVIRI to auditory studies. In standard fMRI, loud acoustic noise is generated by the rapid switching of the gradient magnetic fields required for image encoding, which interferes with auditory stimuli and enforces inefficient and slow sampling strategies. We demonstrate a fMRI method that uses parallel imaging and redesigned gradient waveforms to both minimize and slow down the gradient switching to substantially reduce acoustic noise while still enabling rapid acquisitions for fMRI. Conventional fMRI is based on a hemodynamic response that is secondary to the underlying neuronal activation. In the final contribution of this thesis, a novel image contrast is introduced that is aimed at the direct observation of neuronal magnetic fields associated with functional activation. Early feasibility studies indicate that the imaging is sensitive to oscillating magnetic fields at amplitudes similar to those observed by magnetoencephalography.
by Thomas Witzel.
Ph.D.
Lin, Fa-Hsuan 1972. "Spatiotemporal brain imaging and modeling." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/18064.
Full textIncludes bibliographical references.
This thesis integrates hardware development, data analysis, and mathematical modeling to facilitate our understanding of brain cognition. Exploration of these brain mechanisms requires both structural and functional knowledge to (i) reconstruct the spatial distribution of the activity, (ii) to estimate when these areas are activated and what is the temporal sequence of activations, and (iii)to determine how the information flows in the large-scale neural network during the execution of cognitive and/or behavioral tasks. Advanced noninvasive medical imaging modalities are able to locate brain activities at high spatial and temporal resolutions. Quantitative modeling of these data is needed to understand how large-scale distributed neuronal interactions underlying perceptual, cognitive, and behavioral functions emerge and change over time. This thesis explores hardware enhancement and novel analytical approaches to improve the spatiotemporal resolution of single (MRI) or combined (MRI/fMRI and MEG/EEG) imaging modalities. In addition, mathematical approaches for identifying large-scale neural networks and their correlation to behavioral measurements are investigated. Part I of the thesis investigates parallel MRI. New hardware and image reconstruction techniques are introduced to improve spatiotemporal resolution and to reduce image distortion in structural and functional MRI. Part II discusses the localization of MEG/EEG signals on the cortical surface using anatomical information from AMTRI, and takes advantage of the high temporal resolution of MEG/EEG measurements to study cortical oscillations in the human auditory system. Part III introduces a multivariate modeling technique to identify "nodes" and "connectivity" in a
(cont.) large-scale neural network and its correlation to behavior measurements in the human motor system.
by Fa-Hsuan Lin.
Ph.D.
Norris, David G. "Diffusion imaging of the brain." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-196833.
Full textNair, Hemanth P. "Brain imaging of developmental learning effects /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004348.
Full textWong, Ho-yin, and 黃浩然. "Disconnectivity in autistic brain." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47326165.
Full textpublished_or_final_version
Psychiatry
Master
Master of Philosophy
Bishop, James Hart. "Imaging Pain And Brain Plasticity: A Longitudinal Structural Imaging Study." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/786.
Full textCot, Sanz Albert. "Absolute quantification in brain SPECT imaging." Doctoral thesis, Universitat Politècnica de Catalunya, 2003. http://hdl.handle.net/10803/6601.
Full textno-invasiva que proporciona imatges funcionals representatives de l'activitat neuronal. Aquesta tècnica permet la visualització i l'anàlisi de diferents òrgans i teixits dins l'àmbit de la Medicina Nuclear.
Malgrat que la inspecció visual de la imatge a vegades és suficient per establir el diagnòstic, la quantificació dels paràmetres de la imatge reconstruida poden millorar la fiabilitat i exactitud del diagnòstic precoç de la malaltia. En particular, la quantificació d'estudis de neurotransmissors de dopamina pot ajudar a detectar els estadis inicials de malalties com el Parkinson. Així mateix, la quantificació permet un seguiment més acurat de l'evolució de la malaltia i una evaluació dels efectes de la terapèutica aplicada.
La quantificació es veu afectada pels efectes degradants de la imatge com són el soroll estadístic, la resposta del sistema col.limador/detector i l'efecte de dispersió i/o atenuació dels fotons en la seva interacció amb la matèria. Alguns d'aquests efectes poden ser corregits mitjançant l'ús d'algoritmes de reconstrucció iteratius.
L'objectiu d'aquesta tesi és aconseguir una quantificació tant absoluta com relativa dels valors numèrics de la imatge reconstruida de manera que reprodueixin la distribució d'activitat real del pacient en el moment de l'adquisició de l'estudi de SPECT. Per aconseguir-ho s'han desenvolupat diferents codis i algoritmes per millorar els mètodes de reconstrucció existents i validar-ne els seus resultats.
La validació i millora dels algoritmes s'ha basat en l'ús de tècniques de simulació Monte Carlo. S'han analitzat els diferents codis Monte Carlo disponibles en l'àmbit de la Medicina Nuclear i s'ha escollit SimSET. La interpretació dels resultats obtinguts i la comparació amb els resultats experimentals ens van dur a incorporar modificacions en el codi original. D'aquesta manera vam obtenir i validar SimSET com a generador d'estudis de SPECT a partir de pacients i objectes virtuals.
La millora dels algoritmes es va basar en la incorporació de models analítics de la resposta del sistema col.limador/detector. La modelització del sistema es va implementar per diferents configuracions i energies de la font amb la utilització del codi Monte Carlo PENELOPE. Així mateix es va dissenyar un nou algoritme iteratiu que incorporés l'efecte 3D del sistema i es va tenir en compte la valoració de la imatge en tot el seu volum.
Finalment, es va proposar una correcció de l'scattering utilitzant el simulador SimSET modificat per tal d'accelerar el procés de reconstrucció. Els valors reconstruits de la imatge ens han permès recuperar més d'un 95\% dels valors originals, permetent per tant la quantificació absoluta de les imatges de SPECT.
Many forms of brain diseases are associated with problems in the neurotransmission systems. One approach to the assessment of such systems is the use of Single Photon Emission Computed Tomography (SPECT) brain imaging. Neurotransmission SPECT has become an important tool in neuroimaging and is today regarded as a useful method in both clinical and basic research. SPECT is able to non-invasively visualize and analyze different organs and tissues functions or properties in Nuclear Medicine.
Although visual inspection is often sufficient to assess neurotransmission imaging, quantification might improve the diagnostic accuracy of SPECT studies of the dopaminergic system. In particular, quantification of neurotransmission SPECT studies in Parkinson Disease could help us to diagnose this illness in the early pre-clinical stages. One of the main research topics in SPECT is to achieve early diagnosis, indeed preclinical diagnosis in neurodegenerative illnesses. In this field detailed analysis of shapes and values of the region of interest (ROIs) of the image is important, thus quantification is needed. Moreover, quantification allows a follow-up of the progression of disease and to assess the effects of potential neuroprotective treatment strategies. Therefore, the aim of this thesis is to achieve quantification of both the absolute activity values and the relative values of the reconstructed SPECT images.
Quantification is affected by the degradation of the image introduced by statistical noise, attenuation, collimator/detector response and scattering effects. Some of these degradations may be corrected by using iterative reconstruction algorithms, which thus enable a more reliable quantification. The importance of correcting degradations in reconstruction algorithms to improve quantification accuracy of brain SPECT studies has been proved.
Monte Carlo simulations are the --gold standard' for testing reconstruction algorithms in Nuclear Medicine. We analyzed the available Monte Carlo codes and we chose SimSET as a virtual phantom simulator. A new stopping criteria in SimSET was established in order to reduce the simulation time. The modified SimSET version was validated as a virtual phantom simulator which reproduces realistic projection data sets in SPECT studies.
Iterative algorithms permit modelling of the projection process, allowing for correction of spatially variant collimator response and the photon crosstalk effect between transaxial slices. Thus, our work was focused on the modelling of the collimator/detector response for the parallel and fan beam configurations using the Monte Carlo code PENELOPE. Moreover, a full 3D reconstruction with OS-EM algorithms was developed.
Finally, scattering has recognized to be one of the most significant degradation effects in SPECT quantification. Nowadays this subject is an intensive field of research in SPECT techniques. Monte Carlo techniques appear to be the most reliable way to include this correction. The use of the modified SimSET simulator accelerates the forward projection process although the computational burden is already a challenge for this technique.
Full 3D reconstruction simultaneously applied with Monte Carlo-based scattering correction and the 3D evaluation procedure is a major upgrade technique in order to obtain valuable, absolute quantitative estimates of the reconstructed images. Once all the degrading effects were corrected, the obtained values were 95\% of the theoretical values. Thus, the absolute quantification was achieved.
Ghatan, Per Hamid. "Imaging brain functions during neuropsychological testing /." Stockholm, 1997. http://diss.kib.ki.se/1997/91-628-2792-8.
Full textElliott, Michael Ramsay. "New approaches in functional brain imaging." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299581.
Full textZhu, Fan. "Brain perfusion imaging : performance and accuracy." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8848.
Full textRiemer, F. "Quantitative whole brain sodium (²³Na) imaging." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1469279/.
Full textDoyle, Francis James Jr. "Metabolic imaging of the murine brain." Thesis, Boston University, 2012. https://hdl.handle.net/2144/12352.
Full textAlzheimer's disease is the sixth leading cause of death in the United States. While the pathology of the disease is not fully understood, it is becoming increasingly apparent that it involves a complex homeostatic system involving multiple metals, including zinc, copper, and iron. There is also growing evidence that demonstrates developmental lead exposure may also have a role in the pathogenesis of the disease. Understanding the role of these elements in Alzheimer's disease and other metal dyshomeostasis related maladies is key in the development of treatments and possible cures. The development of metallomic imaging using systems like Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) shows great promise in tracking the distribution of individual elements in physiological tissues. However, the process is both time- and resource-consuming. In an effort to alleviate these issues, we developed a method for creating calibration standards for both LA-ICP-MS and LA-ICP-OES (Laser Ablation Inductively Coupled Plasma Optical Emission Spectrometry) and a method for creating 60µm sections for laser ablation. In addition, we also explored the capabilities and sensitivity of a LA-ICP-OES system for metallomic imaging using murine brains. While imaging of the 60µm sections will require additional calibration and fine-tuning, we were able to successfully image and identify physiological areas of interest in the murine brain by elemental distribution. Continued development of this technology will lead to better optical emission spectrometry image resolution, while freeing up the LAICP-MS for ultra-trace elemental and isotopic analysis.
Wiśniowska, Agata Elżbieta. "Towards brain-wide noninvasive molecular imaging." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122128.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
An intricate interplay of signaling molecules underlies brain activity, yet studying these molecular events in living whole organisms remains a challenge. Magnetic resonance imaging (MRI) is the most promising imaging modality for development of molecular signaling sensors with deeper tissue penetration than optical imaging, and better spatial resolution and more dynamic potential in sensor design, compared to radioactive probes. MRI molecular sensors, however, have largely required micromolar concentrations to achieve detectable signals. In order to detect signaling molecules in the brain at their native low nanomolar concentrations, an improvement in MRI molecular sensors is necessary. Here we introduce a new in vivo imaging paradigm that uses vasoactive probes (vasoprobes) that couple molecular signals to vascular responses. We apply the vasoprobes to detect molecular targets at nanomolar concentrations in living rodent brains, thus satisfying the sensitivity requirement for imaging endogenous signaling events. Even with more sensitive probes, molecular imaging of the brain is further complicated by the presence of the blood-brain barrier (BBB), designed by nature to protect this most vital of organs. We have therefore implemented a means to permit noninvasive delivery of imaging agents following ultrasonic BBB opening. We use the ultrasound technique to deliver another potent class of contrast agents, superparamagnetic iron oxides, and we show that effective permeation of brain tissue is achieved using this approach. We have also designed ultrasensitive vasoprobe variants designed to permeate the brain completely noninvasively, using endogenous transporter-mediated mechanisms. We present preliminary results based on this approach and discuss future directions.
by Agata E. Wiśniowska.
Ph. D. in Medical Engineering and Medical Physics
Ph.D.inMedicalEngineeringandMedicalPhysics Harvard-MIT Program in Health Sciences and Technology
Liu, Mianxin. "The brain at criticality : variability of brain spontaneous activity and relevance to brain functions." HKBU Institutional Repository, 2020. https://repository.hkbu.edu.hk/etd_oa/809.
Full textErrangi, Bhargav Kumar. "A diffusion tensor imaging study of." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28156.
Full textCommittee Chair: James K. Rilling; Committee Chair: Xiaoping Hu; Committee Member: Shella Keilholz; Committee Member: Todd M. Preuss.
丁莹 and Ying Ding. "Magnetic resonance diffusion characterization of brain diseases." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B4961762X.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
Børstad, Thomas Kristoffersen. "Intraoperative Ultrasound Strain Imaging of Brain Tumors." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14039.
Full textSteel, Robby M. "Structural brain imaging in schizophrenia : contemporary issues." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/25214.
Full textCiumas, Carolina. "Multimethodological brain imaging studies of human epilepsy /." Stockholm, 2007. http://diss.kib.ki.se/2007/978-91-7357-268-2/.
Full textRen, Wuwei. "Brain Imaging with a Coded Pinhole Mask." Thesis, KTH, Medicinsk teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101911.
Full textRobillard, Cynthia. "Functional brain imaging of space motion sickness." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104482.
Full textLe mal des transports, bien qu'expérimenté depuis des milliers d'années, est somme toute majoritairement méconnu. Entre autre, la raison d'être de ce trouble n'est pas encore comprise ainsi que sa neuroanatomie et sa neurophysiologie sous-jacentes.Une récente théorie stipule que le mal des transports serait le résultats d'un mécanisme qui limiterait certaine activités moteurs volontaires inappropriées pouvant causer des changements involontaires de la fonction vestibulaire et donc, mener à une distorsion de la posture, des patrons moteurs et du contrôle visuel (Watt et al., 1992). À la lumière de cette théorie, le mal des transports peut probablement être mieux étudié dans des conditions de mouvements actifs plutôt que passifs. Pour cette raison, dans cette thèse, la stimulation coriolis (SC) autogénérée a été utilisée afin d'induire le mal des transports chez des sujets susceptibles. Une caractéristique importante de la SC est que pour un mouvement de tête donné, le patron de la stimulation vestibulaire dépend de la direction globale de la rotation du corps.Cette thèse consiste en trois parties. Premièrement, une méthode a dû être conçue afin de pouvoir repositionner les sujets de façon precise à l'intérieur du scannographe de tomographie par émission de positons après qu'ils aient effectué la stimulation active du mal des transports. Deuxièment, les effets de la SC furent évalués par une étude d'imagerie cérébrale fonctionnelle. La tomographie par émission de positons a été utilisé pour déterminer quelle partie du cerveau sont actives lorsqu'une personne éprouve les signes, symptômes et réactions émotionnelles du mal des transports. Troisièment, les conséquences des patrons spécifiques à la direction de la stimulation vestibulaire par la SC ont été étudiés par la détermination des effets du sens de la rotation sur l'adaptation à la SC.À la suite de ces expériences, un support pour la tête sécuritaire et efficace fut développé, quelques structures du cerveau impliquées dans le mal des transports ont été révélées et une méthode unique générant le mal des transports en laboratoire a plus amplement été caractérisée.
Cheng, Shi, and 程实. "Magnetic resonance imaging investigation of brain networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/210181.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
He, Jiabao. "Functional brain imaging with fMRI and MEG." Thesis, University of Nottingham, 2005. http://eprints.nottingham.ac.uk/12371/.
Full textBarnes, D. "Quantitative magnetic resonance imaging of the brain." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234819.
Full textSpiteri, Michaela. "Imaging biomarkers in paediatric brain resection MRI." Thesis, University of Surrey, 2017. http://epubs.surrey.ac.uk/842478/.
Full textOu, Wanmei. "Spatio-temporal analysis in functional brain imaging." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/57775.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 119-137).
Localizing sources of activity from electroencephalography (EEG) and magnetoencephalography (MEG) measurements involves solving an ill-posed inverse problem, where infinitely many source distribution patterns can give rise to identical measurements. This thesis aims to improve the accuracy of source localization by incorporating spatio-temporal models into the reconstruction procedure. First, we introduce a novel method for current source estimation, which we call the l₁l₂-norm source estimator. The underlying model captures the sparseness of the active areas in space while encouraging smooth temporal dynamics. We compute the current source estimates efficiently by solving a second-order cone programming problem. By considering all time points simultaneously, we achieve accurate and stable results as confirmed by the experiments using simulated and human MEG data. Although the l₁l₂-norm estimator enables accurate source estimation, it still faces challenges when the current sources are close to each other in space. To alleviate problems caused by the limited spatial resolution of EEG/MEG measurements, we introduce a new method to incorporate information from functional magnetic resonance imaging (fMRI) into the estimation algorithm.
(cont.) Whereas EEG/MEG record neural activity, fMRI reflects hemodynamic activity in the brain with high spatial resolution. We examine empirically the neurovascular coupling in simultaneously recorded MEG and diffuse optical imaging (DOI) data, which also reflects hemodynamic activity and is compatible with MEG recordings. Our results suggest that the neural activity and hemodynamic responses are aligned in space. However, the relationship between the temporal dynamics of the two types of signals is non-linear and varies from region to region. Based on these findings, we develop the fMRI-informed regional EEG/MEG source estimator (FIRE). This method is based on a generative model that encourages similar spatial patterns but allows for differences in time courses across imaging modalities. Our experiments with both Monte Carlo simulation and human fMRI-EEG/MEG data demonstrate that FIRE significantly reduces ambiguities in source localization and accurately captures the timing of activation in adjacent functional regions.
by Wanmei Ou.
Ph.D.
Zarogianni, Eleni. "Machine learning and brain imaging in psychosis." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22814.
Full textFiorenzato, Eleonora. "Cognitive and Brain Imaging Changes in Parkinsonism." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3424966.
Full textLa presente tesi è formata da tre parti principali: la prima teorica mentre le due seguenti sono sperimentali. La prima parte, composta di due capitoli, introdurrà le caratteristiche cliniche e neuropatologiche sottostanti ai disturbi parkinsoniani, in particolare nella malattia di Parkinson (PD) e nei parkinsonismi atipici — atrofia multisistemica (MSA) e paralisi progressiva sopranucleare (PSP) (Capitolo 1). Nello specifico, PD ed MSA sono definite come sinucleinopatie per la presenza di aggregati di sinucleina, mentre la PSP che è caratterizzata dall’accumulo di proteina tau rientra a far parte delle tauopatie. Invece, il Capitolo 2 fornirà una panoramica delle disfunzioni cognitive che caratterizzano questi disturbi e fornirà inoltre evidenze circa i meccanismi biologici e i cambiamenti strutturali che sono alla base delle alterazioni cognitive. Nella seconda e la terza parte sono riportati alcuni studi che ho condotto durante il dottorato di ricerca. In particolare, nel Capitolo 3 riporto i risultati dei miei studi sugli strumenti di screening cognitivo più sensibili nel rilevare alterazioni cognitive nei parkinsonismi atipici rispetto ai pazienti con PD. Nel successivo studio invece ho investigato la progressione del declino cognitivo in questi disturbi (Capitolo 4). Infine, ho investigato con studi di risonanza magnetica i cambiamenti strutturali che sottendono le alterazioni cognitive nel PD (Capitolo 5) e nella MSA (Capitolo 6). Seguiranno le conclusioni generali, in cui discuto le conseguenze cliniche dei risultati ottenuti negli studi cognitivi e di imaging (Capitolo 7). PARTE I – Background teorico Capitolo 1: I disturbi parkinsoniani I disturbi parkinsoniani sono caratterizzati da una diversa patologia sottostante. Nel PD ed MSA ci sono aggregati di sinucleina rispettivamente nei neuroni dopaminergici o nelle cellule gliali, mentre i pazienti con PSP presentano delle aggregazioni di proteina tau che determina la formazione di ammassi neurofibrillari (Daniel, de Bruin, & Lees, 1995; Dickson, 1999). Le manifestazioni cliniche dipendono dalle caratteristiche di aggregati proteici e dall’entità di diffusione della malattia nelle regioni corticali e sottocorticali (Halliday, Holton, Revesz, & Dickson, 2011). Quindi, il presente capitolo illustrerà la patologia sottostante nel PD, MSA e PSP, saranno poi descritte le diverse caratteristiche cliniche ed infine, saranno presentati i più recenti criteri diagnostici di questi disturbi (e.g., Gelb, Oliver, & Gilman, 1999; Gilman et al., 2008; Höglinger et al., 2017). Capitolo 2: Caratteristiche cognitive e i sottostanti meccanismi nei disturbi parkinsoniani I sintomi non-motori rappresentano una parte cruciale dello spettro dei disturbi parkinsoniani, in particolare le disfunzioni cognitive, inclusa la demenza, sono probabilmente tra i sintomi non-motori più rilevanti, in quanto influenzano l'autonomia funzionale dei pazienti, incrementano il carico di gestione del caregiver ed hanno un notevole impatto socioeconomico (Keranen et al., 2003; McCrone et al., 2011; Vossius, Larsen, Janvin, & Aarsland, 2011). La prima parte di questo capitolo fornirà una panoramica sulle disfunzioni cognitive nel PD, MSA e PSP. Saranno inoltre riportati i criteri clinici per la diagnosi di declino cognitivo lieve e di demenza nel PD (Dubois et al., 2007; Emre et al., 2007; Litvan et al., 2012), al contrario invece non esistono al momento criteri disponibili per valutare le sindromi cognitive in PSP e MSA. Infine, la seconda e la terza parte di questo capitolo forniranno evidenze sui meccanismi biologici e sui cambiamenti strutturali sottostanti alle alterazioni cognitive in questi disturbi. PARTE II - Studi sulle manifestazioni cognitive nei disturbi parkinsoniani Capitolo 3: Performance al Montreal Cognitive Assessment e Mini-Mental State Examination nella paralisi sopranucleare progresiva, atrofia multisistemica e malattia di Parkinson Vi è un generale consenso nel riconoscere che le alterazioni cognitive siano frequenti nei PD e negli altri disturbi parkinsoniani (Aarsland et al., 2017; Brown et al., 2010; Gerstenecker, 2017). Pertanto, nella pratica clinica possono essere adottate delle scale brevi di screening cognitivo, per supportare il clinico nel processo diagnostico (Marras, Troster, Kulisevsky, & Stebbins, 2014). Il Mini-Mental State Examination (MMSE) è la scala più utilizzata (Folstein, Folstein, & McHugh, 1975), anche se MMSE è relativamente insensibile nell’identificare rilevare disfunzioni cognitive nei disturbi parkinsoniani principalmente perché non indaga il dominio fronto-esecutivo (Hoops et al., 2009). Al contrario, il Montreal Cognitive Assessment (MoCA), un altro strumento di screening cognitivo ampiamente utilizzato nei pazienti con PD (Nasreddine et al., 2005), ha mostrato un’elevata sensibilità e specificità nell’identificazione di alterazioni cognitive nei PD (Gill, Freshman, Blender, & Ravina, 2008; Hoops et al., 2009; Zadikoff et al., 2008), come anche in altre malattie neurodegenerative come l’Alzheimer, la demenza da corpi di Lewy (DLB) e la malattia di Huntington (Biundo et al., 2016b; Hoops et al., 2009; Nasreddine et al., 2005; Videnovic et al., 2010). Tuttavia, vi sono poche evidenze sull’uso del MoCA nei parkinsonismi atipici, in particolare nella PSP ed MSA (Kawahara et al., 2015). Pertanto, lo scopo del presente studio era di determinare se il MoCA fosse più sensibile del comunemente utilizzato MMSE nel rilevare alterazioni cognitive nei pazienti con probabile PSP e MSA, rispetto al PD. In questo studio multicentrico, che ha coinvolto altri tre centri europei, sono state somministrate le scale MMSE e MoCA a 130 pazienti: 35 MSA, 30 PSP e 65 pazienti PD appaiati per età, scolarità e sesso. Sono state valutate le differenze tra i gruppi per MMSE, MoCA, e i loro subitem; infine sono state calcolate le curve ROC (Receiver-Operating Characteristic). Dai risultati emerge che la media del MMSE è superiore al punteggio medio del MoCA in ogni gruppo di pazienti: MSA (27.7 ± 2.4 vs. 22.9 ± 3.0, p<0.0001), PSP (26.0 ± 2.9 vs. 18.2 ± 3.9, p<0.0001), e PD (27.3 ± 2.0 vs. 22.3 ± 3.5, p<0.0001). Inoltre, il punteggio totale MoCA così come il suo subitem di fluenza fonemica è in grado di differenziare la PSP da MSA e PD con un’alta specificità e moderata sensibilità. Specificamente, un punteggio uguale o inferiore a sette parole al minuto sembra supportare una diagnosi di PSP (PSP vs PD: 86% specificità, sensibilità al 70%, PSP vs MSA: 71% specificità, sensibilità al 70%). Al contrario, nel MMSE è stato possibile osservare un ‘effetto-soffitto’ per la maggior parte dei subitem, ad eccezione del subitem dei ‘due pentagoni’, in cui i pazienti con PSP hanno una prestazione peggiore rispetto a MSA e PD. I nostri risultati suggeriscono che PSP ed MSA, similmente al PD, possono presentare una prestazione normale al MMSE ma deficitaria al MoCA. In conclusione, il MoCA è più sensibile del MMSE nel rilevare disfunzioni cognitive nei parkinsonismi atipici ed insieme al suo subitem di fluenza verbale sembra essere un valido test per supportare una diagnosi di PSP. Capitolo 4: Valutazione prospettica delle disfunzioni cognitive nei disturbi parkinsoniani Evidenze in ambito clinico e di ricerca suggeriscono che le disfunzioni cognitive nei disturbi parkinsoniani siano progressive. Tuttavia, in letteratura vi sono pochi studi longitudinali che indagano la progressione cognitiva in pazienti con PSP ed MSA rispetto a pazienti PD (Dubois & Pillon, 2005; Rittman et al., 2013; Soliveri, 2000). In particolare, i precedenti studi si basano solo su scale globali di screening cognitivo, oppure su valutazioni neuropsicologiche parziali che non esaminano l'intero spettro delle abilità cognitive nei cinque domini (i.e., attenzione/memoria di lavoro, esecutivo, mnesico, visuospaziale e del linguaggio). Inoltre, sebbene siano stati formulati criteri clinici per la diagnosi di declino cognitivo lieve (MCI) e di demenza in pazienti PD (Dubois et al., 2007; Litvan et al., 2012), rimane ancora da investigare se tali criteri possano essere applicati anche nei parkinsonismi atipici (Marras et al., 2014). Date tali premesse, gli obiettivi del presente studio sono stati: i) valutare la severità delle alterazioni cognitive in pazienti PSP ed MSA utilizzando i criteri validati nei pazienti PD, per identificare gli stati cognitivi (i.e., MCI o demenza); ii) esaminare la sensibilità di due strumenti di screening cognitivo ampiamente utilizzati, (i.e., MMSE e MoCA), nel differenziare il profilo cognitivo globale di pazienti MSA, PSP e PD; iii) caratterizzare la progressione del declino cognitivo nei cinque domini, il profilo comportamentale e infine confrontare il profilo cognitivo al follow-up tra i vari disturbi parkinsoniani. Il nostro campione includeva 18 pazienti con PSP, 12 MSA e 30 pazienti con PD appaiati per età, scolarità e sesso, che sono stati valutati alla baseline e al follow-up a 15 mesi. Sono stati raccolti dati demografici e clinici; inoltre dal punto di vista cognitivo è stata selezionata una batteria di test neuropsicologici completa, specifica per l’identificazione di deficit cognitivi in pazienti PD, secondo i criteri pubblicati di ‘Livello II’ (Dubois et al., 2007; Litvan et al., 2012; Marras et al., 2014). Abbiamo quindi applicato tali criteri anche a pazienti MSA e PSP, dato che non esistono criteri pubblicati per i parkinsonismi atipici. Infine, sono state utilizzate analisi statistiche di tipo non-parametrico. Dai nostri risultati emerge che i pazienti con PSP hanno un declino cognitivo più severo rispetto a pazienti PD ed MSA. Nello specifico, al follow-up è stato possibile osservare un marcato declino a carico del dominio esecutivo e del linguaggio nel gruppo con PSP. Le valutazioni cognitive alla baseline e al follow-up erano concordanti, ed entrambe confermano che i pazienti PSP hanno una prestazione peggiore rispetto ai pazienti PD ed MSA: in particolare, nello Stroop test, nelle fluenze verbali (semantica e fonematica) e nel MoCA. Valutando la severità dei deficit cognitivi, abbiamo inoltre trovato diverse percentuali di diagnosi cognitive (i.e., profilo nella norma, MCI vs. demenza) tra i tre gruppi. In particolare, la percentuale più elevata di pazienti con demenza era nel gruppo con PSP rispetto ai pazienti MSA (i.e., 33% vs. nessun paziente con demenza), anche se la durata di malattia era simile. Inoltre, tra i pazienti MSA e PSP con un profilo MCI-multidominio alla baseline, solo pazienti con PSP passano ad una diagnosi di demenza al follow-up. Infine nel gruppo di pazienti PD, nonostante avessero una durata di malattia più lunga, la percentuale di soggetti che passano ad una diagnosi di demenza era inferiore rispetto al gruppo con PSP (7% vs. 16%), nonostante entrambi i gruppi avessero una gravità di MCI simile alla baseline. Complessivamente questi risultati suggeriscono un più rapido e severo declino cognitivo in soggetti PSP, mentre i pazienti MSA mostrano generalmente deficit più limitati. La scala globale MoCA sembra essere maggiormente sensibile, rispetto al MMSE, nel rilevare cambiamenti cognitivi, in particolare nella PSP. Tuttavia il MoCA mostra una sensibilità inferiore rispetto al MMSE nell’identificare un declino cognitivo al follow-up in pazienti PD; quindi il MMSE sembra essere uno strumento migliore per monitorare longitudinalmente cambiamenti cognitivi in pazienti PD. Riguardo al profilo comportamentale, i pazienti PSP riportano più comunemente rispetto ai pazienti PD: apatia, ansia e depressione. Infine, l'analisi dei subitem rivela che i pazienti PSP mostrano un peggioramento ‘clinicamente significativo’ dopo 15 mesi soprattutto nei subitem attentivo-esecutivi (Trial Making Test parte B e il disegno di un orologio). Tuttavia è stato possibile osservare che alcuni pazienti hanno anche un miglioramento in specifici subitem al follow-up. Questo miglioramento potrebbe essere attribuibile ad una più elevata dose farmacologica (nonostante il trattamento dopaminergico alla baseline non fosse significativamente diverso al follow-up). Tuttavia, è importante notare che tali alterazioni erano presenti soprattutto in subitem sensibili alle problematiche motorie (i.e., disegno di figure e collegamento di cerchi con una penna) che quindi potrebbero aver alterato la performance. Questi limiti della scala MoCA e MMSE sono già stati osservati in precedenza nei pazienti con PD (Biundo et al., 2016b; Hu et al., 2014), e possibilmente sono ancora più pronunciati nei parkinsonismi atipici. In conclusione i nostri risultati rivelano che i pazienti PSP hanno una performance notevolmente alterata rispetto agli altri disturbi parkinsoniani (MSA e PD), e dopo circa 6 anni di durata di malattia, il 33% dei pazienti PSP ha una diagnosi di demenza. Questa severa progressione è probabilmente associata ad una diffusione di aggregati tau che coinvolge anche strutture corticali. Al contrario, il pattern di compromissione cognitiva in pazienti con MSA è meno severo, e probabilmente è associato ad una predominanza sottocorticale della patologia, con un coinvolgimento corticale solo secondario alle alterazioni sottocorticali. Pertanto, i nostri risultati suggeriscono che la valutazione neuropsicologica può essere utile nella differenziazione dei profili cognitivi nei parkinsonismi atipici e per monitorare la progressione della malattia. PARTE III – Studi di neuroimmagine sulle sinucleinopatie Capitolo 5: Effetti dei depositi di amiloide sulle manifestazioni cognitive e motorie nella malattia di Parkinson Alterazioni cognitive, in particolare deficit esecutivi, possono essere osservati anche nelle prime fasi del PD (Aarsland, Bronnick, Larsen, Tysnes & Alves, 2009). La disfunzione frontostriatale del sistema dopaminergico può influenzare la presenza di problemi esecutivi ed attentivi (Bruck, Aalto, Nurmi, Bergman, & Rinne, 2005), tuttavia al momento le evidenze relative al trasportatore striatale di dopamina (DAT) sono inconsistenti (Delgado-Alvarado, Gago, Navalpotro-Gomez, Jimenez-Urbieta, & Rodriguez-Oroz, 2016). I meccanismi neuropatologici che stanno alla base delle alterazioni cognitive nei PD sono eterogenei (Irwin, Lee, & Trojanowski, 2013; Kehagia, Barker & Robbins, 2010), ed il contributo del deposito di amiloide in aggiunta alla sinucleinopatia rimane ancora poco definito, soprattutto nelle prime fasi della malattia. Pertanto, lo scopo del presente studio è stato quello di indagare l'interazione tra depositi di amiloide nel circuito frontostriatale, deficit dopaminergico striatale, grado di atrofia cerebrale ed il loro contributo nelle alterazioni cognitive (i.e., funzioni fronto-esecutive) nelle prime fasi del PD. Una coorte multicentrica di 33 pazienti con PD ricavata dal ‘Parkinson's Progression Markers Initiative’ è stata sottoposta a una tomografia ad emissione di positroni (PET) con radiofarmaco [18F]florbetaben, tomografia ad emissione di fotone singolo (SPECT) con radiofarmaco [123I]FP-CIT, risonanza magnetica (MRI) strutturale, valutazione clinica e cognitiva. Dai nostri risultati emerge che elevati livelli di depositi di amiloide erano associati ad una riduzione del deficit dopaminergico nello striato dorsale (rispetto ai bassi livelli di depositi di amiloide), ad un aumento dell’atrofia cerebrale in regioni frontali ed occipitali, e ad una tendenza a manifestare più frequentemente alterazioni cognitive globali (come valutato dal MoCA), ed in test fronto-esecutivi. Inoltre, le deposizioni di amiloide nelle regioni frontostriatali erano inversamente correlate alla performance cognitiva. Nel complesso i nostri risultati suggeriscono che pazienti con PD in fase iniziale di malattia e amiloidosi hanno un più elevato grado di atrofia cerebrale e possono esperire maggiori deficit cognitivi (i.e., disfunzioni esecutive) e alterazioni motorie rispetto a soggetti negativi all’amiloide. I nostri risultati sembrano essere in linea con una recente ipotesi neuropatologica che considera il danno e disfunzione assonale a livello sinaptico come un elemento caratteristico del PD (Tagliaferro & Burke, 2016). Infatti, i neuroni del sistema dopaminergico sono particolarmente vulnerabili alla sinucleinopatia a causa delle loro caratteristiche assonali: gli assoni sono lunghi, sottili e non mielinizzati. Questa ipotesi è confermata anche da studi di neuroimmagine PET con traccianti che si legano al DAT (Caminiti et al., 2017), suggerendo che le aggregazioni di sinucleina nel PD possono influenzare la funzione sinaptica e la trasmissione di segnale sin dalle prime fasi della malattia. I nostri risultati suggeriscono quindi una possibile interazione tra depositi di amiloide e sinucleinopatia, in cui la presenza di amiloide può facilitare la diffusione di sinucleina (i.e., corpi di Lewy) (Toledo et al., 2016), pertanto questa interazione può contribuire ulteriormente alla vulnerabilità assonale. In linea con questa ipotesi, i nostri risultati sembrano confermare che le deposizioni di amiloide agiscono sinergicamente con la sinucleinopatia, influenzando le manifestazioni cliniche del PD. Capitolo 6: Profilo neurostrutturale dell’atrofia multisistemica con alterazioni cognitive A differenza di altre sinucleinopatie (e.g., PD e DLB), la presenza di demenza è considerata un criterio di esclusione nella diagnosi di MSA (Gilman et al., 2008), tuttavia vi è una crescente evidenza che pazienti affetti da MSA possano manifestare alterazioni cognitive, che includono disfunzioni esecutive ma anche deficit cognitivi multidominio, e in alcuni casi anche demenza (Gerstenecker, 2017). Il MMSE è una scala cognitiva globale comunemente utilizzata nella pratica clinica, e recentemente uno studio multicentrico ha suggerito l’utilizzo di un cutoff <27 per aumentare la sensibilità di tale scala nell'identificare alterazioni cognitive in pazienti MSA (Auzou et al., 2015). I meccanismi che sottendono le disfunzioni cognitive in soggetti MSA non sono ancora stati identificati ed evidenze da studi di MRI suggeriscono un discreto contributo corticale e sottocorticale per spiegare tali alterazioni cognitive (Kim et al., 2015; Lee et al., 2016a). Tuttavia questi risultati sono basati su un numero relativamente piccolo di pazienti e in vari stadi di malattia, inoltre sono studi basati su singoli centri. Pertanto, lo scopo del nostro studio multicentrico è stato quello caratterizzare i cambiamenti anatomici associati ad alterazioni cognitive in pazienti MSA e di investigare le differenze strutturali corticali e sottocorticali rispetto ad un campione di soggetti sani. Abbiamo quindi esaminato retrospettivamente 72 pazienti MSA, e definito 50 MSA come cognitivamente normali (MSA-NC) e 22 con alterazioni cognitive (MSA-CI) utilizzando il cutoff del MMSE <27. Abbiamo inoltre confrontato direttamente i due sottogruppi di MSA, e comparato l’intero gruppo di MSA ad un campione di 36 controlli sani (HC) utilizzando un’analisi di ‘morfometria basata sui voxel’ che analizzava la sostanza grigia e bianca. Inoltre, abbiamo applicato anche una segmentazione automatizzata dei volumi sottocorticali. Dai nostri risultati emerge che i pazienti MSA, rispetto a soggetti sani, hanno una diffusa atrofia corticale (i.e., che coinvolge bilateralmente aree frontali, occipito-temporali e parietali), sottocorticale ed alterazioni alla sostanza bianca. Tuttavia, nel confronto diretto, i soggetti MSA-CI mostrano solo una focale riduzione del volume a carico della corteccia prefrontale dorsolaterale sinistra rispetto a pazienti MSA-NC. Tali risultati suggeriscono che la patologia corticale abbia un effetto marginale sulle alterazioni cognitive nei pazienti MSA. Suggeriamo quindi che le alterazioni cognitive siano piuttosto determinate da una degenerazione frontostriatale focale, che sembra essere in linea con il concetto di ‘alterazioni cognitive sottocorticali’.
Lin, Xiao Hong. "Mapping of brain activation and functional brain networks associated with cognition by using fNIRS or concurrent fNIRS-EEG recordings." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3953720.
Full textOlsson, CJ. "Imaging imagining actions." Doctoral thesis, Umeå : Section for Physiology, Department of Integrative Medical Biology, Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1910.
Full textCamborata, Caterina. "Capsule networks: a new approach for brain imaging." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18127/.
Full textHuang, Ruey-Song. "Multisensory representations of space multimodal brain imaging approaches /." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3214724.
Full textTitle from first page of PDF file (viewed July 11, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
Fredriksson, Jesper. "Evolutionary Development of Brain Imaging Meta-analysis Systems." Licentiate thesis, KTH, Numerical Analysis and Computer Science, NADA, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1440.
Full textCounsell, Serena Jane. "Quantitative magnetic resonance imaging of the preterm brain." Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/11362.
Full textSchroeter, Matthias. "Enlightening the brain : optical imaging in cognitive neuroscience /." Leipzig ; München : MPI for Human Cognitive and Brain Sciences, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014995433&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full textKemp, Brad J. "Attenuation correction for SPECT imaging of the brain." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59403.
Full textIt has been determined that the reconstructed images are overcorrected in the centre by 5%, and the optimum correction occurs for a reduced coefficient of 0.09 cm$ sp{-1}$. The overcorrection is due to increased attenuation at the edges of all projections where the path length through the bone is greater, although the bone also increases the scatter at the projection edges.
A correction scheme which uses effective bone and water coefficients was developed to compensate for the attenuation. Alternatively, prior to attenuation correction, a common scatter correction was found to be effective in explicitly removing the bone and water scatter.
Cowie, Christopher James Andrew. "Quantitative magnetic resonance imaging in traumatic brain injury." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1730.
Full textBrignell, Christopher. "Shape analysis and statistical modelling in brain imaging." Thesis, University of Nottingham, 2007. http://eprints.nottingham.ac.uk/12106/.
Full textYogarajah, M. "Imaging structural connections of the brain in epilepsy." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1435547/.
Full textGoksan, Sezgi. "Imaging nociceptive brain activity in the newborn infant." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:ea4d49fc-cf7e-4775-bb82-ddb3385cc2d9.
Full textPedrosa, Micael Cardoso. "A web portal for Portuguese brain imaging network." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2163.
Full textA Imagiologia Cerebral (IC) está na fronteira entre a neurologia, engenharia e física. écnicas de imagens médicas multimodais, tais como a Ressonância Magnética (MRI e fMRI) e Espectroscopia (MRS), Tomografia Computadorizada por Emissão de Fotões/Positrões (SPECT/PET), entre outros, são emergentes ferramentas de pesquisa médica que pode fornecer informações valiosas para o diagnóstico de doenças do cérebro. Eletroencefalograma de alta resolução (HR-EEG), técnicas para sincronizar e fundir seus resultados de análise e várias técnicas de imagem são também parte de IC. Em Portugal, dado o facto que a maioria das áreas relacionadas com IC (por exemplo, medicina, engenharia ou física) são assuntos de investigação em muitos grupos de P&D, um consórcio de universidades de Aveiro, Coimbra, Minho e Porto criou a Rede Nacional de Imagiologia Funcional Cerebral (RNIFC). A RNIFC é uma associação sem fins lucrativos que foi formalizada e assinada em fevereiro de 2009. Actualmente, com o suporte de sistemas digitais para armazenar imagens médicas, é possível partilhar dados entre essas instituições para melhorar o diagnóstico, e permitir investigações entre a comunidade médica de diferentes instituições. O principal objectivo desta dissertação é descrever a implementação dos serviços de sistemas de informação essenciais para a Brain Imaging Network (BIN) que suportam actualmente o RNIFC acessível através do Portal BIN, o principal ponto de entrada para a BING. O Portal BIN permite aos pesquisadores na comunidade BING espalhadas pelo país e no estrangeiro, quer para solicitar o acesso a instrumentos científicos ou para recuperar os seus casos e executar as suas análises. ABSTRACT: Brain Imaging is in the frontier between neurology, engineering and physics. Multimodal medical imaging techniques, such as Magnetic Resonance Imaging (MRI and fMRI) and Spectroscopy (MRS), Single Photon/Positron Emitting Tomography (SPECT/PET) among others, are emergent medical research tools that can provide valuable information for diagnosis of brain diseases. High-resolution electroencephalogram (HR-EEG), techniques for synchronizing and fuse its analysis results and several imaging techniques are also part of BI. In Portugal, given fact that most of the BI related areas (e.g. medical, engineering or physics) are subjects of research in many R&D groups, a consortium of the universities of Aveiro, Coimbra, Minho and Porto created the National Functional Brain Imaging Network (RNIFC). The RNIFC is a non-profitable association that was formalized and signed in February 2009. Currently, with the support of digital systems to store medical images, it is possible to share data among these institutions to improve diagnosis, and allow investigations by the medical community among different institutions. The main objective of this thesis is to describe the implementation of the essential Brain Imaging Network (BIN) information systems services that currently support the RNIFC accessible through the BIN Portal, the main entry point for the BING. BIN Portal enables researchers in the BING community scattered along the country and abroad either to apply for access to the scientific instruments or to retrieve their cases and run their analysis.
Lee, Jongho. "Steady-state imaging techniques for functional brain MRI /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Full textNiranjan, A. "Functional magnetic resonance imaging of the mouse brain." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1543368/.
Full textSamore, Andrea <1987>. "Algorithms and Numerical Methods for Electrical Brain Imaging." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8019/1/SamoreTesiPhD.pdf.
Full textMason, Erica Ellis. "Magnetic particle imaging for intraoperative breast cancer margin assessment and functional brain imaging." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128037.
Full textThesis: Ph. D., Harvard-MIT Program in Health Sciences and Technology, 2020
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 171-185).
Magnetic Particle Imaging (MPI) is an emerging tracer-based imaging modality that uniquely images the nonlinear magnetization of superparamagnetic iron oxide nanoparticles (SPIOs). MPI boasts high sensitivity, zero background signal, positive contrast, fast temporal resolution, and quantitative detection. The field of MPI is currently preclinical, and this work aims to scale MPI to human sizes by developing and validating it for two clinical applications: tumor detection and imaging for intraoperative margin assessment during breast-conserving surgery (BCS), and functional neuroimaging. For margin assessment in BCS, a hand-held Magnetic Particle detector and a small-bore MPI imager are assessed for intraoperative use along with an injected SPIO agent. The goal is to detect positive margins during surgery and thus reduce the need for future reexcision. Both hardware systems are validated using clinically relevant phantoms. For functional Magnetic Particle Imaging (fMPI) of the brain, a continuous time-series MPI imager is developed and validated for imaging of cerebral blood volume (CBV) changes during functional activation. The goal is improved sensitivity beyond the capabilities of current functional imaging modalities. We present initial results of in vivo rodent fMPI in a small-bore imager, and the design of a human head-sized system, with implementation underway. Through the collective development of these MPI hardware systems and validation of their potential for these two clinical applications, this work aims to catalyze the expansion of MPI into the clinical setting.
by Erica Ellis Mason.
Ph. D.
Ph.D. Harvard-MIT Program in Health Sciences and Technology
Talvik, Mirjam. "Clinical molecular imaging of schizophrenia /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-587-5/.
Full textDube, Jonathan. "Follow-up computed tomography imaging in patients who have suffered traumatic brain injury in Zimbabwe." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/2971.
Full textIntroduction: Traumatic brain injury (TBI) is frequently associated with mortality and morbidity in low-income countries. Computed Tomography Brain (CTB) imaging aid in the management of patients by accurately exploring primary and secondary brain injuries following trauma. However, there is controversy among researchers on the benefits of follow-up CTB imaging (FCTBI) amongst patients presenting with TBI showing a normal baseline scan. As such, in an attempt to address the contention, the primary focus of this research study was to explore the role of FCTBI with regards to the clinical status of such patients. The secondary focus was to determine the timing of performing FCTBI post TBI. Method: A retrospective cross sectional quantitative design was conducted for this research study. A total sampling strategy was employed on medical records of 85 patients treated at the research site in Zimbabwe. Data were collected over a two year period. Adult patients between the ages of 18 and 75, with TBI and who had a normal first CTBI1 (primary scan done upon hospital admission) were included in this research study. The evolution of different types of brain pathology diagnosed on FCTBI in affected patients were recorded on data collection sheets. An analysis then followed to establish whether the sample patients had developed any neurological complications. Results: The study showed that in 85 patients with TBI, 36% recorded abnormal radiological findings on FCTBI with subdural haematoma (19%) being the most common intracranial lesion followed by intracerebral haemorrhage (8%), subarachnoid haemorrhage (6%) and lastly, pneumocephalus and epidural haematoma (1% respectively). The most frequent causal mechanism of trauma was road traffic accidents (RTAs) at 58%. Males with TBI comprised a higher proportion (53%) than did females (47%). The performance of CTBI1 at 8 hours post trauma occurrence, within a recommended hospital observation period of 20 hours post trauma occurrence, may provide sufficient time for lesions to evolve and thus determine the appropriate patient management. The young adult age group of 26-35 years was found to be more susceptible to TBI. Conclusion: FCTBI was found to be of value in timely detection of evolving intracranial lesions which enabled appropriate management of patients. The current study recommends that patients who exhibit a declining Glasgow Coma Scale (GCS) score and deteriorating neurological status undergo a FCTBI.