Дисертації з теми "Schizophrenia Magnetic resonance imaging"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Schizophrenia Magnetic resonance imaging".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Harvey, Ian. "Magnetic resonance imaging in schizophrenia." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/19829.
Повний текст джерелаHoward, Robert John Michael Webster. "Magnetic resonance imaging of the brain in late paraphrenia." Thesis, Queen Mary, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243821.
Повний текст джерелаAlexander-Bloch, Aaron Felix. "Brain networks in magnetic resonance imaging studies of typical development and childhood-onset schizophrenia." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608247.
Повний текст джерелаCollinson, Simon Lowes. "Studies of cerebral laterality in early onset schizophrenia." Thesis, University of Oxford, 2001. http://ora.ox.ac.uk/objects/uuid:c1e832af-5a0b-4f72-89af-9f4a295246a2.
Повний текст джерелаCurrie, James. "Neuroeconomics investigation of decision-making in schizophrenia using functional magnetic resonance imaging." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=235437.
Повний текст джерелаLeung, Mei-kei, and 梁美琪. "MRI brain abnormality in first episode schizophrenia before and after treatment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43572303.
Повний текст джерелаMichael, Andrew M. "Imaging schizophrenia : data fusion approaches to characterize and classify /." Online version of thesis, 2009. http://hdl.handle.net/1850/9673.
Повний текст джерелаGradin, Iade Victoria B. "Major depression and schizophrenia : investigation of neural mechanisms using neuroimaging and computational modeling of brain function." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=184011.
Повний текст джерелаGoodby, Emmeline. "Cognitive and magnetic resonance imaging endophenotypes of psychosis measured in first episode patients and their unaffected first degree relatives." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610467.
Повний текст джерелаDeng, Yi, and 鄧藝. "From neuroimaging to proteomics in schizophrenia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43278516.
Повний текст джерелаYamamoto, Utako. "Fiber Tracking and Tractography with Magnetic Resonance Diffusion Tensor Imaging for Quantitative Evaluation of Schizophrenia." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174938.
Повний текст джерелаWoodruff, Peter Walter Ralph. "Magnetic resonance imaging evidence for abnormally lateralised and fronto-temporally dissociated brain regions in schizophrenia." Thesis, King's College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286762.
Повний текст джерелаCheung, Vinci, and 張穎思. "Structural white matter abnormalities in never-medicated patients withfirst-episode schizophrenia: a diffusiontensor imaging study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39793734.
Повний текст джерелаMori, Yasuo. "Effect of phase-encoding direction on group analysis of resting-state functional magnetic resonance imaging." Kyoto University, 2021. http://hdl.handle.net/2433/261590.
Повний текст джерелаWhyte, Marie-Claire. "Neuropsychological assessment and functional magnetic resonance imaging of verbal declarative memory performance in relatives of schizophrenia patients and controls." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/27660.
Повний текст джерелаPrice, Gary. "Investigating structural brain changes in the first-episode of schizophrenia using volumetric, magnetisation transfer and diffusion tensor-magnetic resonance imaging." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/17231/.
Повний текст джерелаKaneko, Yoshio A. "Resting-state hyperconnectivity of the anticorrelated intrinsic networks in schizophrenic patients and their unaffected siblings." Yale University, 2010. http://ymtdl.med.yale.edu/theses/available/etd-03092010-145235/.
Повний текст джерелаVáša, František. "Characterising disease-related and developmental changes in correlation-derived structural and functional brain networks." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277816.
Повний текст джерелаWhitford, Thomas James. "A longitudinal study of brain structure in the early stages of schizophrenia." University of Sydney, 2007. http://hdl.handle.net/2123/1895.
Повний текст джерелаSchizophrenia is a severe mental illness that affects approximately 1% of the population worldwide, and which typically has a devastating effect on the lives of its sufferers. The characteristic symptoms of the disease include hallucinations, delusions, disorganized thought and reduced emotional expression. While many of the early theories of schizophrenia focused on its psychosocial foundations, more recent theories have focused on the neurobiological underpinnings of the disease. This thesis has four primary aims: 1) to use magnetic resonance imaging (MRI) to identify the structural brain abnormalities present in patients suffering from their first episode of schizophrenia (FES), 2) to elucidate whether these abnormalities were static or progressive over the first 2-3 years of patients’ illness, 3) to identify the relationship between these neuroanatomical abnormalities and patients’ clinical profile, and 4) to identify the normative relationship between longitudinal changes in neuroanatomy and electrophysiology in healthy participants, and to compare this to the relationship observed between these two indices in patients with FES. The aim of Chapter 2 was to use MRI to identify the neuroanatomical changes that occur over adolescence in healthy participants, and to identify the normative relationship between the neuroanatomical changes and electrophysiological changes associated with healthy periadolescent brain maturation. MRI and electroencephalographic (EEG) scans were acquired from 138 healthy participants between the ages of 10 and 30 years. The MRI scans were segmented into grey matter (GM) and white matter (WM) images, before being parcellated into the frontal, temporal, parietal and occipital lobes. Absolute EEG power was calculated for the slow-wave, alpha and beta frequency bands, for the corresponding cortical regions. The age-related changes in regional tissue volumes and regional EEG power were inferred with a regression model. The results indicated that the healthy participants experienced accelerated GM loss, EEG power loss and WM gain in the frontal and parietal lobes between the ages of 10 and 20 years, which decelerated between the ages of 20 and 30 years. A linear relationship was also observed between the maturational changes in regional GM volumes and EEG power in the frontal and parietal lobes. These results indicate that the periadolescent period is a time of great structural and electrophysiological change in the healthy human brain. The aim of Chapter 3 was to identify the GM abnormalities present in patients with FES, both at the time of their first presentation to mental health services (baseline), and over the first 2-3 years of their illness (follow-up). MRI scans were acquired from 41 patients with FES at baseline, and 47 matched healthy control subjects. Of these participants, 25 FES patients and 26 controls returned 2-3 years later for a follow-up scan. The analysis technique of voxel-based morphometry (VBM) was used in conjunction with the Statistical Parametric Mapping (SPM) software package in order to identify the regions of GM difference between the groups at baseline. The related analysis technique of tensor-based morphometry (TBM) was used to identify subjects’ longitudinal GM change over the follow-up interval. Relative to the healthy controls, the FES patients were observed to exhibit widespread GM reductions in the frontal, parietal and temporal cortices and cerebellum at baseline, as well as more circumscribed regions of GM increase, particularly in the occipital lobe. Furthermore, the FES patients lost considerably more GM over the follow-up interval than the controls, particularly in the parietal and temporal cortices. These results indicate that patients with FES exhibit significant structural brain abnormalities very early in the course of their illness, and that these abnormalities progress over the first few years of their illness. Chapter 4 employed the same methodology to investigate the white matter abnormalities exhibited by the FES subjects relative to the controls, both at baseline and over the follow-up interval. Compared to controls, the FES patients exhibited volumetric WM deficits in the frontal and temporal lobes at baseline, as well as volumetric increases at the fronto-parietal junction bilaterally. Furthermore, the FES patients lost considerably more WM over the follow-up interval than did the controls in the middle and inferior temporal cortex bilaterally. While there is substantial evidence indicating that abnormalities in the maturational processes of myelination play a significant role in the development of WM abnormalities in FES, the observed longitudinal reductions in WM were consistent with the death of a select population of temporal lobe neurons over the follow-up interval. The aim of Chapter 5 was to investigate the clinical correlates of the GM abnormalities exhibited by the FES patients at baseline. The volumes of four distinct cerebral regions where 31 patients with FES exhibited reduced GM volumes relative to 30 matched controls were calculated and correlated with patients’ scores on three primary symptom dimensions: Disorganization, Reality Distortion and Psychomotor Poverty. The results indicated that the greater the degree of atrophy exhibited by the FES patients in three of these four ‘regions-of-reduction’, the less severe their degree of Reality Distortion. These results suggest that an excessive amount of GM atrophy may in fact preclude the formation of hallucinations or highly systematized delusions in patients with FES. The aim of Chapter 6 was to identify the relationship between the longitudinal changes in brain structure and brain electrophysiology exhibited by 19 FES patients over the first 2-3 years of their illness, and to compare it to the normative relationship between the two indices reported in Chapter 2. The methodology employed for the parcellation of the MRI and EEG data was identical to Chapter 2. The results indicated that, in contrast to the healthy controls, the longitudinal reduction in GM volume exhibited by the FES patients was not associated with a corresponding reduction in EEG power in any brain lobe. In contrast, EEG power was observed to be maintained or even to increase over the follow-up interval in these patients. These results were consistent with the FES patients experiencing an abnormal elevation of neural synchrony. Such an abnormality in neural synchrony could potentially form the basis of the dysfunctional neural connectivity that has been widely proposed to underlie the functional deficits present in patients with schizophrenia. The primary aim of Chapter 7 was to assimilate the findings from the preceding empirical chapters with the theoretical framework provided in the literature, into an integrated and testable model of schizophrenia. The model emphasized dysfunctions in brain maturation, specifically in the normative processes of synaptic ‘pruning’ and axonal myelination, as playing a key role in the development of disintegrated neural activity and the subsequent onset of schizophrenic symptoms. The model concluded with the novel proposal that disintegrated neural activity arises from abnormal elevations in the synchrony of synaptic activity in patients with first-episode schizophrenia.
Monté, Rubio Gemma C. "Computational analysis of schizophrenia: Implementation of a multivariate model of anatomical differences." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/348264.
Повний текст джерелаAunque el patrón anatómico asociado a la esquizofrenia es conocido, el cuadro clínico es a menudo difícil de diferenciar en su debut. Un extendido objetivo en neurociencias es encontrar alteraciones morfológicas asociadas a una enfermedad. Muchos estudios han aplicado la Morfología Basada en Voxel (VBM), pero es univariante y no cumple la asunción biológicamente más plausible. Esto conduce a la neuroimagen hacia entornos multivariantes como el reconocimiento de patrones. Estas técnicas requieren de una caracterización de los datos que cuantifique la variabilidad neuroanatomica. Si los datos no están modelados con precisión y/o las caracterizaciones no incorporan información clave, la precisión de las predicciones será limitada. Es necesario explorar características a partir de imágenes y seleccionar las más informativas. También es esencial el preprocesado tipo-VBM requerido. Si la segmentación no es precisa, la normalización tampoco puede serlo. Para abordar estos aspectos, esta tesis se divide en tres estudios. El primero compara algoritmos de segmentación de SPM: “Unified segmentation” (US) y “New Segmentation” (NS), y de FSL: “FMRIB’s Automated Segmentation tool” (FAST). Se realizó una comparación entre algoritmos usando diferentes métodos con las imágenes IBSR (vivo.cornell.edu/display/individual5017), por incluir tejidos segmentados por expertos. En el estudio 2, una máquina de aprendizaje de Procesos Gaussianos fue aplicada para predecir edad, género e índice de masa corporal (IMC) usando los datos IXI (biomedic.doc.ic.ac.uk/brain-development/index.php?n=Main.Datasets). Las imágenes fueron preprocesadas con SPM12. Después, caracterizaciones de éstos datos fueron evaluadas, así como su relación con el suavizado (FWHM: 0-20mm). El estudio 3 consistió en aplicar la metodología del estudio 2 a la esquizofrenia (datos FIDMAG). Nuestra hipótesis fue que las características óptimas del estudio 2 también lo serían en éste. Los primeros resultados mostraron que NS fue la herramienta más equilibrada en cuanto a sensibilidad y especificidad. También NS obtuvo el coeficiente Jaccard más alto, dando segmentaciones más similares a las realizadas por expertos. FAST obtuvo el índice menor. En el estudio 2, los resultados de las predicciones señalaron los momentos escalares como la mejor característica. Curiosamente, la sustancia gris (GM) no fue la óptima para predecir la edad, y la sustancia blanca fue la mejor para predecir IMC. Se observó alta dependencia del suavizado. En el estudio 3 los momentos escalares aportaron mejor caracterización para predecir esquizofrenia que la GM, confirmado la hipótesis a priori. En conclusión los momentos escalares proveen de características que alcanzan mayor precisión en el reconocimiento de patrones para predecir la esquizofrenia. Éste enfoque podría extenderse a otras enfermedades tanto en investigación y como ayuda al diagnóstico diferencial en la clínica diaria.
Rauer, Lisa [Verfasser], and Oliver [Akademischer Betreuer] Gruber. "Examinations of pathomechanisms in schizophrenic and bipolar disorders – results from two functional magnetic resonance imaging studies / Lisa Rauer ; Betreuer: Oliver Gruber." Heidelberg : Universitätsbibliothek Heidelberg, 2021. http://d-nb.info/1226541658/34.
Повний текст джерелаSpanghero, Maristela Schaufelberger. "Avaliação longitudinal de pacientes portadores de esquizofrenia e transtorno esquizofreniforme utilizando ressonância magnética de crânio." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-14102008-155130/.
Повний текст джерелаMorphometric brain abnormalities have been extensively described in subjects with schizophrenia in many structural magnetic resonance imaging studies, the most consistent findings being ventricular enlargement and gray matter reductions in frontal and temporal neocortices, insula, thalamus and hippocampus/parahippocampal gyri. However, the nature and course of these abnormalities have not yet been clarified. Although the main hypothesis regarding the etiopathology of schizophrenia implies the presence of early and stable anatomical brains abnormalities, longitudinal magnetic resonance imaging studies have suggested that, despite being present at the first episode of psychosis, or even before its onset, some brain abnormalities may be progressive, especially at the first few years of the disorder. In the present study, gray matter volumes were compared, at baseline and longitudinally, between first-episode patients with schizophrenia or schizophreniform disorder and non-psychotic controls. Structural magnetic resonance images from 62 patients and 94 controls, recruited from the same catchment area for an epidemiological study in the city of São Paulo, were acquired using a 1.5 Tesla scanner. After a mean period of 16 months, 39 patients and 52 controls were rescanned. Images were analyzed by voxel-based morphometry with the Statistical Parametric Mapping software and statistical significance was set at p<0.05, corrected for multiple comparisons. The initial betweengroup comparison revealed gray matter reductions in patients, when compared to controls, in the right and left prefrontal cortices, left superior temporal cortex, bilateral insula and right hippocampus and parahipocampal gyrus. Longitudinally, patients exhibited significantly greater gray matter preservation in left superior temporal cortex and right hippocampus/ parahipocampal gyrus. There were no areas showing significantly greater gray matter loss in patients relative to controls in the longitudinal analysis. There were no gray matter differences between medicated and unmedicated patients, neither at baseline nor at follow-up. The findings of the baseline comparison are in accordance with previous studies that reported brain abnormalities in association with first episode psychosis. The longitudinal results are in accordance with some of the follow-up neuroimaging studies conducted to date and support the hypothesis that the described abnormalities could have been present before the onset of illness. Also, these findings suggest that, at least considering the follow-up interval of our study, such brain changes are not progressive. The volumetric differences between patients and controls observed in our study were not caused by antipsychotic medication effects
Bassitt, Débora Pastore. ""Crítica de doença e alterações cerebrais estruturais na esquizofrenia"." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-26102005-133339/.
Повний текст джерелаFifth patients with schizophrenia were evaluated with psychopathological and insight scales and cerebral magnetic ressonance (made also on thirty normal controls). There was a greater insight impairment on unemployed patients and on these receiving two or more antipsychotics. There was a positive correlation between greater insight impairment and disorganization, excitation, hostility and total negative symptoms, besides a negative correlation with anxiety, guilt feelings, preoccupation and depression. Patients with less insight had a reduction of gray matter volume on the lingual gyrus, occipital lobe, that disappeared when correction for multiple comparisons was made. Schizophrenic patients had gray matter reduction in an 27 cm3 area in insula and frontal, temporal and parietal lobes
Torres, Ulysses dos Santos. "Estudo de alterações estruturais cerebrais em pacientes com esquizofrenia crônica e de primeiro episódio através de imagens por ressonância magnética com morfometria baseada no voxel." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5151/tde-30062016-160432/.
Повний текст джерелаIntroduction: Although structural brain changes in schizophrenia have been repeatedly demonstrated in magnetic resonance imaging (MRI) studies, it remains unclear whether these are static or progressive in nature. While longitudinal MRI studies have been traditionally used to assess the issue of progression, cross-sectional neuroimaging studies directly comparing first-episode and chronic schizophrenia patients to healthy controls have been very scarce to date. With the recent interest in multisite mega-analyses combining structural MRI data from multiple centers aiming at increased statistical power, the present multisite voxel-based morphometry (VBM) study was carried out to examine patterns of brain structural changes according to the different stages of illness and to ascertain which (if any) of such structural abnormalities would be specifically correlated to potential clinical moderators, including cumulative exposure to antipsychotics, illness duration and overall illness severity. Methods: We gathered a large sample of schizophrenia patients (161, being 99 chronic and 62 first-episode) and controls (151) from four previous morphometric MRI studies (1.5 T) carried out in the same geographical region of Brazil. Image processing and analyses were conducted using Statistical Parametric Mapping (SPM8) software with the diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) algorithm. Group effects on regional gray matter (GM) volumes were investigated through whole-brain voxel-wise comparisons using General Linear Model Analysis of Co-variance (ANCOVA), always including total GM volume, scan protocol, age and gender as nuisance variables. Finally, correlation analyses were performed between the aforementioned clinical moderators and regional and global brain volumes. Results: First-episode schizophrenia subjects displayed subtle volumetric deficits relative to controls in a circumscribed brain regional network identified only in small volume-corrected (SVC) analyses ]p < 0.05, family-wise error (FWE)-corrected], including the insula, temporolimbic structures and striatum. Chronic schizophrenia patients, on the other hand, demonstrated an extensive pattern of regional GM volume decreases relative to controls, involving bilateral superior, inferior and orbital frontal cortices, right middle frontal cortex, bilateral anterior cingulate cortices, bilateral insulae and right superior and middle temporal cortices (p < 0.05, FWE-corrected over the whole brain). Significant negative correlations were detected between life-time cumulative exposure to antipsychotics and total GM and white matter volumes in schizophrenia patients, but no significant relationship was found between indices of antipsychotic usage and relative GM volume in any specific brain region. There were also significant negative correlations between duration of illness and relative GM volumes of the left insula, and right anterior cingulate and dorsolateral prefrontal cortices on SVC analyses for conjoined (first-episode and chronic) schizophrenia groups. Conclusion: The above data indicate that: a) brain changes associated with the diagnosis of schizophrenia are more widespread in chronic schizophrenia compared to first-episode patients; b) relative GM volume deficits in specific brain regions may vary as a function of duration of illness; c) cumulative doses of antipsychotics usage were associated with brain volumes globally rather than regionally
Gudlowski, Yehonala. "Neurophysiologische Substrate von Störungen des Belohnungssystems und kognitiver Funktionen bei unmedizierten Schizophreniepatienten untersucht mittels funktioneller Magnetresonanztomographie und 1 H-Magnetresonanzspektroskopie." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2010. http://dx.doi.org/10.18452/16047.
Повний текст джерелаImaging studies have demonstrated that for schizophrenic patients a correlation exists between positive symptoms and changes in the patterns of mesolimbic activity. Especially the changes in the ncl. accumbens (Nac) were interpreted in connection with the reward system. The signals indicating reward are thought to be processed by the anterior cingulum (ACC). These structures attribute meaning to the reward signals. In the anticipation phase of a potentially rewarding stimulus, dopaminergic signals from the VTA are generated in prediction of expected or aberrant outcome, thus modulating the Nac. Data indicate a direct modulation of the Nac. by glutamatergic neurons of the anterior cingulum. A major aim of this thesis is to establish a connection between the reward associated dopaminergic signals of the ncl. accumbens and the glutamatergic projections of the acc in unmedicated schizophrenic patients and healthy controls. The methods included measurements of proton magnetic resonance spectroscopy (1H-MRS) and functional MRI-scans done at a 3-Tesla tomograph. The paradigm applied was a modified version of the monetary incentive delay paradigm (Knutson et al. 2000). In healthy volunteers we found a significant negative correlation between the glutamate concentration in the ACC and the BOLD-contrast in the Nac (reward versus neutral), in contrast to the findings in schizophrenic patients. A significant higher BOLD-contrast was seen in the anticipation phase in healthy controls. The results were incorporated in a model of NMDA-R-Hypoaktivity. In addition to discussing the functional aspects for the structures involved the model was further expanded to include the hypothesis of a disturbed balance between dopamine-D1- and -D2-receptor activity and a dysfunctional hippocampal gating-process. The so constructed model suggests a profound striato-thalamo-cortical filter disturbance as the basis of the observed aberrations in the reward processing in schizophrenic disorders.
Oliveira, Ícaro Agenor Ferreira de. "Avaliação perfusional e de conectividade funcional cerebrais em esquizofrenia por imagens por ressonância magnética." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-28092017-110039/.
Повний текст джерелаSchizophrenia is a disabling psychiatric disorder that affects around 1% of the population worldwide. Delusions, hallucinations, disorganized thought, and cognitive deficits are the main features of schizophrenia. Physiologically, in addition to functional and structural abnormalities, changes in neuronal activity are reported. Since the Cerebral Blood Flow (CBF) is directly related with neuronal activity, the Magnetic Resonance Imaging (MRI) technique called Arterial Spin Labeling (ASL), which allows the quantification of CBF, is a useful tool in brain functional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Patients with Schizophrenia, recruited at the Clinical Hospital (HCFMRP), presented a reduction of CBF in bilateral regions of the frontal pole and superior frontal gyrus, right medial frontal gyrus, triangular and opercular parts of the right inferior frontal gyrus, posterior division of left supramarginal gyrus, superior and inferior division of left lateral occipital cortex and occipital pole. Functional connectivity, assessed by three different methods (seed-based, independent component analysis and graph theory), was impaired in regions involving patients\' motor, sensory and cognitive functions. Therefore, using a noninvasive imaging technique, it was possible to observe CBF deficits and alterations in the functional organization of the brain of schizophrenia patients, related to the symptoms and characteristics of the psychopathology.
Walton, Esther, Daniel Geisler, Johannes Hass, Jingyu Liu, Jessica Turner, Anastasia Yendiki, Michael N. Smolka, et al. "The Impact of Genome-Wide Supported Schizophrenia Risk Variants in the Neurogranin Gene on Brain Structure and Function." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-132122.
Повний текст джерелаGarcia, Giovana Jorge. "Efeito do nitroprussiato de sódio em voluntários saudáveis e pacientes portadores de esquizofrenia: um estudo de ressonância magnética funcional." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/17/17148/tde-21072016-144647/.
Повний текст джерелаDespite numerous studies focusing on the understanding of schizophrenia, its etiology remains unknown. Currently, available antipsychotic medications are mainly based on dopamine hypothesis, however, they exhibit partial efficacy in the treatment of the symptoms. Therefore, other neural systems have been investigated and, in this context, the glutamatergic hypothesis gained great importance. This hypothesis postulates the presence of a hypoactivity of the N-methyl-D-aspartate glutamate receptor in schizophrenia and, consequently, a deregulation of nitric oxide neurotransmission. A recent clinical trial with the administration of sodium nitroprusside, a nitric oxide donor, showed significant results in improving the symptoms of schizophrenic patients, however, no neuroimaging study investigated what are the effects of this drug on the central nervous system. The neural networks were discovered from the growing field of functional neuroimaging study and the default mode network is one of the most studied in schizophrenia. The recent functional neuroimaging studies have shown alterations in the functioning of this neural network in patients with the disease, highlighting the importance of the default mode network in the understanding of schizophrenia. In this way, the present study investigated the acute effects of sodium nitroprusside administration in the functional connectivity of the default mode network using blood oxygen level dependent (BOLD) functional magnetic resonance imaging in patients with schizophrenia and healthy volunteers. Schizophrenic patients are divided into two groups according to antipsychotic medication used: group treated without clozapine (n = 13) and group treated with clozapine (n = 13). Healthy volunteers were also divided into control group (n = 14) and control group with passive listening task (n = 5). All schizophrenic patients and healthy volunteers were subjected to a sodium nitroprusside infusion protocol simultaneously to acquisition of functional images. Our results showed increased default mode network functional connectivity with the drug infusion in patients with schizophrenia, mainly in the right hemisphere, while this same pattern was not found in healthy controls. In addition, the increase in connectivity was distinct between groups of patients because it was earlier and more extensive in the group of patients that was not in use of clozapine antipsychotic. We also note that the drug modulatory effect occurred on default mode network regions already studied and strongly implicated in the schizophrenia pathogenesis. Thus, our neurofunctional research contributed to the understanding of the sodium nitroprusside therapeutic effects on the schizophrenia symptoms. Our findings also underline the importance of sodium nitroprusside as a new adjuvant pharmacological tool in the treatment of schizophrenia
Walton, Esther, Daniel Geisler, Johannes Hass, Jingyu Liu, Jessica Turner, Anastasia Yendiki, Michael N. Smolka, et al. "The Impact of Genome-Wide Supported Schizophrenia Risk Variants in the Neurogranin Gene on Brain Structure and Function." Public Library of Science, 2013. https://tud.qucosa.de/id/qucosa%3A27422.
Повний текст джерелаSerpa, Mauricio Henriques. "Avaliação longitudinal de alterações microestruturais cerebrais estado-dependentes em indivíduos com primeiro episódio psicótico, associadas à atividade da enzima fosfolipase A2." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-19062017-075614/.
Повний текст джерелаINTRODUCTION: Psychotic disorders are frequent conditions in the general population and are associated to severe morbidity and functional impairment. Notwithstanding, the pathophysiological basis of such disorders is still under investigation. Post-mortem neuropathologic investigations and in vivo neuroimaging studies have pointed to the occurrence of abnormalities in the microstructure of brain white matter (WM) in such clinical conditions, which are associated to changes in brain connectivity. However, no previous neuroimaging investigation has specifically examined whether such microstructural abnormalities would be state-dependent, i.e., whether such changes could relate to the illness phase. Another field of biological investigation in psychosis points to changes in the activity of phospholipase A2 enzyme (PLA2), which is essential to several functions implicated in brain homeostasis, such as the maintenance of cellular membrane, myelination and inflammatory activity. Previous studies suggest the existence of a relationship between changes on PLA2 activity and schizophrenia phase. Nonetheless, no translational study to date has examined the potential interplay between PLA2 activity and WM microstructural abnormalities in psychotic patients. OBJECTIVES: To investigate the hypothesis that WM microstructural changes observed in patients during the acute first-episode psychosis (FEP) are potentially reversible following clinical remission; to investigate possible state-dependent changes in PLA2 activity in FEP; and to examine interactions between clinical manifestations, brain WM microstructure and PLA2 activity in the pathophysiology of FEP. METODOLOGY: Patients with non-affective FEP were evaluated in two time points: during the acute phase (T0) and following sustained remission (T1). A control group of healthy volunteers (HC) was also longitudinally studied. In order to investigate state-dependent WM microstructure changes, voxelwise analyses of brain maps of anisotropy (fractional anisotropy, FA) and diffusivity (trace, TR) indexes were conducted, as well as correlations between such DTI metrics, clinical variables and PLA2 activity. The activity of the three main PLA2 subgroups was assessed in platelets using a radioenzymatic method. RESULTS: 25 FEP and 51 HC were evaluated at T0 (clinical and demographic data, MRI scanning, and blood collection). Out of these, 21 FEP and 36 HC also underwent a second MRI acquisition. At baseline (T0), FEP patients presented widespread reduction of FA (p < 0.05, FDR), affecting mainly fronto-limbic WM and associative, projective and commissural fasciculi. Longitudinal analyses showed that clinical remission was associated with FA increase in WM tracts that were affected at T0 (p < 0.001, uncorrected), besides robust inverse correlations between FA increase and symptoms reduction over time (p < 0.05, FDR). PLA2 analyses failed to show state-dependent effects or consistent correlations to DTI indexes. CONCLUSION: WM changes affecting brain tracts critical to the integration of perceptual information, cognition and emotions are detectable soon after the onset of FEP and may partially reverse in direct relation to the remission of acute psychotic symptoms. Our findings reinforce the view that WM abnormalities are a key neurobiological feature of acute psychotic disorders, and that recovery from such WM pathology can lead to amelioration of symptoms. In the other hand, it seems that PLA2 activity has no direct relationship to the disease state or modulatory effects on the dynamic WM changes observed herein. Studies with larger samples and with more time points evaluations are necessary to confirm and expand the findings reported herein
Dupuy, Maud. "De l'imagerie cérébrale au recueil de données en vie quotidienne : vers une compréhension intégrée des liens entre fonctionnement cognitif, expériences émotionnelles, perception du temps et symptômes de la schizophrénie." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0366/document.
Повний текст джерелаSchizophrenia is characterized by significant variability over time in symptoms and functioning. However, little information is available concerning the short-term variability of symptoms and their associated phenomena (cognitive functioning, emotional experiences, perception of time), and despite their importance for providing precise descriptions of this complex mental disorder. Traditional laboratory-based assessments are confronted with a number of methodological limitations that make it impossible to assess such variability. This doctoral thesis therefore aims at providing missing information concerning the short-term temporal links between cognitive functioning, emotional experience, and time perception relative to the manifestation of symptoms of schizophrenia and examines the cerebral correlates of these associations. To address this issue, an innovative approach was applied that combined Ecological Momentary Assessment (EMA) using mobile technologies with Magnetic Resonance Imaging (MRI) of the brain. The EMA methodology identified the roles of cognitive performance, emotional experience and time perception in the expression of symptoms of schizophrenia over short time intervals in the patient’s daily life. MRI revealed the anatomical and functional correlates of these relationships, confirming in particular the central role of fronto-temporo-cerebellar regions in this disorder. Taken together, this dual approach provides novel insights into the underlying mechanisms of symptom expression in individuals with schizophrenia
González, Ballester Miguel Ángel. "Morphometric analysis of brain structures in MRI." Thesis, University of Oxford, 1999. http://ora.ox.ac.uk/objects/uuid:9b70d5d7-5a38-454c-b545-696b726092b8.
Повний текст джерелаPrado, Daniel Barbosa de Almeida. "Conectividade inter-hemisférica com respeito ao gênero na esquizofrenia: um estudo de tractografia baseado em imagem de ressonância magnética por tensor de difusão." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/17/17140/tde-31082013-000226/.
Повний текст джерелаSchizophrenia is a highly complex mental disorder and no theory to date was able to fully explain the etiology of this disorder. One of the existing theories advocates that interhemispheric communication, which occurs through the corpus callosum and the anterior and posterior commissures, might be impaired in schizophrenia. Our study was designed to investigate whether there are interhemispheric connectivity (IC) alterations in schizophrenia and whether these alterations are influenced by gender through the comparison of schizophrenia patients with their first-degree relatives and healthy controls using diffusion tensor imaging (DTI). We enrolled 30 schizophrenia patients diagnosed according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and selected from the Group of Atypical Medications of the Schizophrenia Outpatient Clinic and the psychiatric ward of the Ribeirão Preto Medical School University Hospital, 30 first-degree relatives of these patients and 30 healthy volunteers. All subjects underwent magnetic resonance imaging (MRI) scans for the acquisition of volumetric and diffusion sequences. The images were post-processed using BrainVoyager QX® version 2.4 to create fractional anisotropy (FA) and mean diffusivity (MD) maps from DTI data. The resulting data were analyzed using voxel-to- voxel analysis of covariance (VANCOVA) for the whole brain. In this analysis, we used age as a co-variable and assessed the influence of gender. Our results showed that schizophrenia patients had altered FA and MD values in structures homologous to the corpus callosum and adjacent frontal areas, suggestive of IC loss in the patients. We also found that gender influenced FA and MD values and, therefore, that IC in schizophrenia patients is influenced by gender. Age was also found to influence IC in our patients. Based on the current conception that FA and MD alterations may indicate myelin impairment and knowing that myelin participates directly in neurochemical reactions of the glutamatergic system in the brain, we can infer that the glutamatergic system, which is implicated in IC, is affected in schizophrenia and is influenced by gender.
Harvey, I. "Nuclear magnetic resonance scanning in schizophrenia." Thesis, University of Edinburgh, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.652194.
Повний текст джерелаLee, Kuan Jin. "Fast magnetic resonance imaging." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397487.
Повний текст джерелаO'Neil, Shannon M. "Magnetic resonance imaging centers /." Online version of thesis, 1994. http://hdl.handle.net/1850/11916.
Повний текст джерелаLu, Wenmiao. "Off-resonance correction in magnetic resonance imaging /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Повний текст джерелаManners, David Neil. "Magnetic resonance imaging and magnetic resonance spectroscopy of skeletal muscle." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269250.
Повний текст джерелаPetropoulos, Labros Spiridon. "Magnetic field issues in magnetic resonance imaging." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1060710667.
Повний текст джерелаCampbell, Jennifer 1975. "Magnetic resonance diffusion tensor imaging." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30809.
Повний текст джерелаThis thesis describes the design and implementation of diffusion tensor imaging on a clinical MRI system. An acquisition sequence was designed and post-processing software developed to create diffusion trace images, scalar anisotropy maps, and anisotropy vector maps. A number of practical imaging problems were addressed and solved, including optimization of sequence parameters, accounting for flow effects, and dealing with eddy currents, patient motion, and ghosting. Experimental validation of the sequence was performed by calculating the trace of the diffusion tensor measured in various isotropic liquids. The results agreed very well with the quantitative values found in the literature, and the scalar anisotropy index was also found to be correct in isotropic phantoms. Anisotropy maps, showing the preferred direction of diffusion, were generated in human brain in vivo. These showed the expected white matter tracts in the corpus callosum.
Lindsay, Alistair. "Magnetic resonance imaging of atherosclerosis." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526491.
Повний текст джерелаGlover, Paul Martin. "High field magnetic resonance imaging." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335575.
Повний текст джерелаYoo, Seung-Schik 1970. "Adaptive functional magnetic resonance imaging." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/70893.
Повний текст джерелаSome research performed with the Harvard-M.I.T. Division of Health Sciences and Technology.
Includes bibliographical references (leaves 132-140).
Functional MRI (fMRI) detects the signal associated with neuronal activation, and has been widely used to map brain functions. Locations of neuronal activation are localized and distributed throughout the brain, however, conventional encoding methods based on k-space acquisition have limited spatial selectivity. To improve it, we propose an adaptive fMRI method using non-Fourier, spatially selective RF encoding. This method follows a strategy of zooming into the locations of activation by progressively eliminating the regions that do not show any apparent activation. In this thesis, the conceptual design and implementation of adaptive fMRI are pursued under the hypothesis that the method may provide a more efficient means to localize functional activities with increased spatial or temporal resolution. The difference between functional detection and mapping is defined, and the multi- resolution approach for functional detection is examined using theoretical models simulating variations in both in-plane and through-plane resolution. We justify the multi-resolution approach experimentally using BOLD CNR as a quantitative measure and compare results to those obtained using theoretical models. We conclude that there is an optimal spatial resolution to obtain maximum detection; when the resolution matches the size of the functional activation. We demonstrated on a conventional 1.5-Tesla system that RF encoding provides a simple means for monitoring irregularly distributed slices throughout the brain without encoding the whole volume. We also show the potential for increased signal-to-noise ratio with Hadamard encoding as well as reduction of the in-flow effect with unique design of excitation pulses.
(cont.) RF encoding was further applied in the implementation of real-time adaptive fMRI method, where we can zoom into the user-defined regions interactively. In order to do so, real-time pulse prescription and data processing capabilities were combined with RF encoding. Our specific implementation consisted of five scan stages tailored to identify the volume of interest, and to increase temporal resolution (from 7.2 to 3.2 seconds) and spatial resolution (from 10 mm to 2.5-mm slice thickness). We successfully demonstrated the principle of the multi- resolution adaptive fMRI method in volunteers performing simple sensorimotor paradigms for simultaneous activation of primary motor as well as cerebellar areas.
by Seung-Schik Yoo.
Ph.D.
Eichner, Cornelius. "Slice-Accelerated Magnetic Resonance Imaging." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184944.
Повний текст джерелаSharkey-Toppen, Travis P. "Imaging Iron and Atherosclerosis by Magnetic Resonance Imaging." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429796182.
Повний текст джерелаYoshimaru, Eriko Suzanne. "Magnetic Resonance Imaging Techniques for Rodent Pulmonary Imaging." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293388.
Повний текст джерелаMA, DAN. "Magnetic Resonance Fingerprinting." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1426170542.
Повний текст джерелаLei, Hao. "Magnetic resonance perfusion imaging and double quantum coherence transfer magnetic resonance spectroscopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0021/NQ45007.pdf.
Повний текст джерелаTymofiyeva, Olga. "Magnetic resonance imaging in dental medicine." Göttingen Sierke, 2010. http://d-nb.info/1002094976/04.
Повний текст джерелаMcDougall, Mary Preston. "Single echo acquisition magnetic resonance imaging." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3324.
Повний текст джерела