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Wisnowski, Jessica Lee. "The specificity of visual recognition impairments following focal brain damage." Diss., University of Iowa, 2007. http://ir.uiowa.edu/etd/136.
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Ungaro, Daniela Maria de Toledo. "Estimativa do tempo de reparo ósseo em dentes com lesão periapical tratados endodonticamente utilizando modelagem matemática /." São José dos Campos, 2018. http://hdl.handle.net/11449/157149.
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Orientador: Ana Paulo Martins GomesCoorientador: Jorge Kennety Silva Formiga
Banca: Symone Cristina Teixeira
Banca: Denise Pontes Raldi
Resumo: Os objetivos deste estudo foram avaliar, com a ajuda de um modelo matemático, o tempo estimado para ocorrer reparo ósseo em dentes com lesão periapical tratados endodonticamente e comparar o volume da lesão periapical (em mm3) após a utilização de dois tipos de medicação intracanal. Para isso, foram selecionados 34 dentes unirradiculares com lesão periapical de pacientes da Disciplina de Endodontia do ICT/SJC-UNESP que necessitavam de tratamento endodôntico. Após a seleção dos dentes, foram obtidas radiografias periapicais (RP) e tomografias computadorizadas de feixe cônico (TCFC) antes de iniciar o tratamento endodôntico (T0). Os dentes foram divididos em dois grupos de acordo com a medicação intracanal utilizada (n=17): G1 - Hidróxido de cálcio associado à Clorexidina Gel 2% e G2 - Ultracal XS®. Foram obtidas novas radiografias periapicais e tomografias (TCFC) após o término do tratamento endodôntico (T1), sendo outras após 3 meses (T2) e também após 6 meses (T3). Os arquivos das tomografias foram exportados no formato DICOM (Digital Imaging and Communications in Medicine) para avaliar a volumetria das lesões pré e pós tratamento (em voxel/mm3) pelo processo de segmentação semiautomático em todos os períodos de tempo pré-estabelecidos (T0, T1, T2 e T3), por meio do software de livre acesso ITK-SNAP1.4.1 (University of North Carolina, Chapel Hill, NC, USA). Após a análise da volumetria das lesões periapicais em todos os períodos de tempo, os dados obtidos foram utilizados pa... (Resumo completo, clicar acesso eletrônico abaixo)
The objectives of this study were to evaluate the estimated time for bone repair in teeth with periapical lesions treated endodontically and to compare the volume of the periapical lesion (in mm3) with the help of a mathematical model after the use of two types of intracanal medication. For this, 34 single rooted teeth with periapical lesion were selected from patients of the Endodontic Discipline of the ICT/SJC-UNESP who needed endodontic treatment. After the teeth were selected, periapical radiography (RP) and cone-beam computed tomography (CBCT) were obtained before starting the endodontic treatment. The teeth were divided into two groups according to the intracanal medications used (n=17): G1 - Calcium hydroxide associated with 2% chlorhexidine gel and G2 - Ultracal XS®. New periapical radiographs and tomographys (CBCT) were obtained after endodontic treatment (T1), others after 3 months (T2) and after 6 months (T3). The files of CBCT were exported in DICOM (Digital Imaging and Communications in Medicine) format to evaluate the volumetry of pre and post-treatment lesions (voxel/mm3 ) by the semi-automatic segmentation process at all the pre-established time periods (T0, T1, T2, T3) through the free access software ITK SNAP-1.4.1 (University of North Carolina, Chapel Hill, NC, USA). After the analysis of the periapical lesion volume in all time periods, the data were used to construct a mathematical model that was used to estimate the bone repair time of the lesion. The data obtained were statistically analyzed by Student's t - test of independent samples (p <0.05). ). There was a decrease in the volume of the periapical lesion in endodontically treated cases and the intracanal medication used, whether calcium hydroxide + chlorhexidine gel 2% or Ultracal®, did not present a significant difference in bone repair time nor in the periapical lesion volume in the...(Complete abstract click electronic access below)
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Da, Cruz Trevor Anthony. "Developing a focal EAE lesion in the spinal cord and its repair with stem cell therapy : a MRI study." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501419.
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Grafft, Amanda Jo. "Academic achievement following childhood onset brain injury." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/3304.
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The degree of academic achievement following early onset brain injury is poorly understood. Furthermore, it is unclear if academic success can be predicted by age of onset or other lesion variables (e.g., size, laterality). The purpose of the current study was to describe patterns of academic achievement in individuals with childhood-onset focal brain lesions and to determine the role of variables in the plasticity or vulnerability of the developing brain with regard to achievement. Academic achievement data were collected from 58 individuals with childhood-onset focal brain lesions. The participants' reading, spelling, and arithmetic scores, as measured by the Wide Range Achievement Test, were analyzed in relation to several neuroanatomical variables, including lesion laterality, lesion site, and lesion size. The relationship between achievement and gender, age of onset, etiology, age at testing, and time since lesion onset was also identified.
As a group, achievement scores did not differ from normative data, and the majority of the sample demonstrated adequate skills in each domain. However, the frequency of deficits was larger than expected when compared to base rates, suggesting vulnerability to early insult. Achievement scores were correlated with intelligence scores, but did not differ based on lesion laterality, lesion site, age of onset, or etiology. Size of lesion was significantly correlated with reading and spelling but not with arithmetic outcomes. Gender differences were identified, with males performing significantly better on the arithmetic measure than females. The age of onset, age at testing, and time since lesion onset were not correlated with achievement scores in any domain. No interactions were found between lesion laterality and gender or lesion site and lesion laterality. An interaction between gender and lesion site was found, but the significance of the finding is unclear. The current findings provide mixed evidence for the plasticity-vulnerability debate, as many individuals were able to achieve adequate academic skills whereas others demonstrated significant impairments. Further research is needed to elucidate factors that may predict achievement outcomes in individuals with childhood-onset focal brain injury.
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Imbrosci, Barbara [Verfasser], Ulf [Gutachter] Eysel, and Dirk [Gutachter] Jancke. "Functional alterations of glutamatergic and GABAergic neurotransmission in the cortical networks surrounding a focal laser lesion in rat visual cortex / Barbara Imbrosci ; Gutachter: Ulf Eysel, Dirk Jancke ; International Graduate School of Neuroscience." Bochum : Ruhr-Universität Bochum, 2012. http://d-nb.info/1161941991/34.
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Old, Sally Louise. "Focal lesions in toxicity studies : methods and models." Thesis, De Montfort University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391200.
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Rowe, Andrea Denise. "Social cognition in patients with focal prefrontal cortical lesions." Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413703.
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Auvray, Nathalie. "Etude comportementale de l'influence du cervelet dans l'acquisition du comportement d'équilibration chez le jeune rat." Rouen, 1987. http://www.theses.fr/1987ROUES051.
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Hart, Michael Gavin. "Network approaches to understanding the functional effects of focal brain lesions." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274018.
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Complex network models of functional connectivity have emerged as a paradigm shift in brain mapping over the past decade. Despite significant attention within the neuroimaging and cognitive neuroscience communities, these approaches have hitherto not been extensively explored in neurosurgery. The aim of this thesis is to investigate how the field of connectomics can contribute to understanding the effects of focal brain lesions and to functional brain mapping in neurosurgery. This datasets for this thesis include a clinical population with focal brain tumours and a cohort focused on healthy adolescent brain development. Multiple network analyses of increasing complexity are performed based upon resting state functional MRI. In patients with focal brain tumours, the full complement of resting state networks were apparent, while also suggesting putative patterns of network plasticity. Connectome analysis was able to identify potential signatures of node robustness and connections at risk that could be used to individually plan surgery. Focal lesions induced the formation of new hubs while down regulating previously established hubs. Overall these data are consistent with a dynamic rather than a static response to the presence of focal lesions. Adolescent brain development demonstrated discrete dynamics with distinct gender specific and age-gender interactions. Network architecture also became more robust, particularly to random removal of nodes and edges. Overall these data provide evidence for the early vulnerability rather than enhanced plasticity of brain networks. In summary, this thesis presents a combined analysis of pathological and healthy development datasets focused on understanding the functional effects of focal brain lesions at a network level. The coda serves as an introduction to a forthcoming study, known as Connectomics and Electrical Stimulation for Augmenting Resection (CAESAR), which is an evolution of the results and methods herein.
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Neal, Jo Anne. "Executive function in healthy volunteers and patients with focal cerebral lesions." Thesis, Bangor University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421677.
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García-Lorenzo, Daniel. "Robust Segmentation of Focal Lesions on Multi-Sequence MRI in Multiple Sclerosis." Phd thesis, Université Rennes 1, 2010. http://tel.archives-ouvertes.fr/tel-00485645.
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La sclérose en plaques (SEP) atteint autour de 80.000 personnes en France. L'imagerie par résonance magnétique (IRM) est un outil essentiel pour le diagnostic de la SEP. Plusieurs bio-marqueurs sont obtenus à partir des IRM, comme le volume des lésions, et sont utilisés comme mesure dans des études cliniques en SEP, notamment pour le développement des nouveaux traitements. La segmentation manuelle des lésions est une tâche encombrante et dont les variabilités intra- et inter-expert sont grandes. Nous avons développé une chaîne de traitement automatique pour la segmentation des lesions focales en SEP. La méthode de segmentation est basée sur l'estimation robuste d'un modèle paramétrique des intensités du cerveau qui permet de détecter les lésions comme des données aberrantes. Nous avons aussi proposé deux méthodes pour ajouter de l'information spatiale avec les algorithmes mean shift et graph cut. Nous avons validé quantitativement notre approche en utilisant des images synthétiques et cliniques, provenant de deux centres différents pour évaluer la précision et la robustesse.
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Theodorsson, Annette. "Estrogen-inducible neuropeptides in the rat brain : role in focal ischemic lesions /." Doctoral thesis, Linköping : Linköpings universitet, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4716.
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García, Lorenzo Daniel. "Robust segmentation of focal lesions on multi-sequence MRI in multiple sclerosis." Rennes 1, 2010. http://www.theses.fr/2010REN1S018.
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La sclérose en plaques (SEP) atteint autour de 80. 000 personnes en France. L'imagerie par résonance magnétique (IRM) est un outil essentiel pour le diagnostic de la SEP. Plusieurs bio-marqueurs sont obtenus à partir des IRM, comme le volume des lésions, et sont utilisés comme mesure dans des études cliniques en SEP, notamment pour le développement des nouveaux traitements. La segmentation manuelle des lésions est une tâche encombrante et dont les variabilités intra- et inter-expert sont grandes. Nous avons développé une chaîne de traitement automatique pour la segmentation des lesions focales en SEP. La méthode de segmentation est basée sur l'estimation robuste d'un modèle paramétrique des intensités du cerveau qui permet de détecter les lésions comme des données aberrantes. Nous avons aussi proposé deux méthodes pour ajouter de l'information spatiale avec les algorithmes mean shift et graph cut. Nous avons validé quantitativement notre approche en utilisant des images synthétiques et cliniques, provenant de deux centres différents pour évaluer la précision et la robustesseMultiple sclerosis (MS) affects around 80. 000 people in France. Magnetic resonance imaging (MRI) is an essential tool for diagnosis of MS and MRI-derived surrogate markers such as MS lesion volumes are often used as measures in MS clinical trials for the development of new treatments. The manual segmentation of these MS lesions is a time-consuming task that shows high inter- and intra-rater variability. We developed an automatic workflow for the segmentation of focal MS lesions on MRI. The segmentation method is based on the robust estimation of a parametric model of the intensities of the brain; lesions are detected as outliers to the model. We proposed two methods to include spatial information in the segmentation using mean shift and graph cut. We performed a quantitative evaluation of our workflow using synthetic and clinical images of two different centers to verify its accuracy and robustness
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Palacio, Navarro Andrea. "Pronóstico neuropsicológico en pacientes pediátricos con epilepsia refractaria lesional focal." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670706.
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L’epilèpsia farmacorrefractària a la infància pot causar importants dèficits cognitius i deteriorament psicoemocional degut tant a les mateixes crisis com als afectes secundaris dels fàrmacs antiepilèptics. Els factors que es relacionen en major o menor grau amb l’afectació cognitiva d’aquests pacients són l’edat de debut de l’epilèpsia, la localització de l’àrea epileptògena i el temps d’evolució, entre d’altres. A l’hora de realitzar un diagnòstic i ponderar possibles tractaments i les seves complicacions és important poder establir un pronòstic precís de l’evolució neuropsicològica del pacient. D’acord amb l’exposat fins ara, el principal objectiu de l’estudi és definir factors de pronòstic neuropsicològic en nens amb epilèpsia refractària.
El present treball estudia una mostra de 81 pacients pediàtrics amb epilèpsia refractària, focal i lesional ingressats a la Unitat d’Epilèpsia de l’Hospital Sant Joan de Déu de Barcelona entre els anys 2005 i 2017.
A partir del perfil neuropsicològic dels pacients, definit a partir de les seves principals funcions cognitives en la infància, s’estableixen 3 subpoblacions semblants a nivell neuropsicològic. Mitjançant l’anàlisis factorial, queden conformats 3 factors que expliquen el 66% de la variabilitat clínica de la mostra: Cognitiu global, Llenguatge i velocitat de processament de la informació, i Simptomatologia afectiva i problemes
de conducta. Les variables que tenen més incidència en la conformació dels factors són l’edat d’inici de l’epilèpsia, el temps d’evolució, l’edat a l’ingrés i l’etiologia. De la correlació d’aquestes poblacions amb la factorització n’obtenim les principals variables clíniques i sociodemogràfiques que incideixen en els diferents perfils cognitius.
Aquest estudi proposa una escala de pronòstic neuropsicològic que permet establir criteris de priorització a l’ingrés de pacients a les unitats d’epilèpsia.La epilepsia farmacorrefractaria en la infancia puede causar importantes déficits cognitivos y deterioro psicoemocional debido tanto a las mismas crisis como a los efectos secundarios de los fármacos antiepilépticos. Los factores que se relacionan en mayor o menor grado con la afectación cognitiva de estos pacientes son la edad de inicio de la epilepsia, la localización del área epileptógena y el tiempo de evolución, entre otros. A la hora de realizar un diagnóstico y ponderar posibles tratamientos y sus complicaciones es importante poder establecer un pronóstico preciso de la evolución neuropsicológica del paciente. El principal objetivo del estudio es definir factores de pronóstico neuropsicológico en niños con epilepsia refractaria. El presente trabajo estudia una muestra de 81 pacientes pediátricos con epilepsia refractaria, focal y lesional ingresados en la Unidad de Epilepsia del Hospital Sant Joan de Déu de Barcelona entre los años 2005 y 2017. A partir del perfil neuropsicológico de los pacientes, definido a partir de sus principales funciones cognitivas en la infancia, se establecen 3 subpoblaciones semejantes a nivel neuropsicológico. Mediante el análisis factorial quedan conformados 3 factores que explican el 66% de la variabilidad clínica de la muestra: Cognitivo global, Lenguaje y velocidad de procesamiento de la información, y Sintomatología afectiva y problemas de conducta. Las variables que tienen más incidencia en la conformación de los factores son la edad de inicio de la epilepsia, el tiempo de evolución, la edad en el ingreso y la etiología. De la correlación de dichas poblaciones con la factorización extraemos las principales variables clínicas y sociodemográficas que inciden en los diferentes perfiles cognitivos. Este estudio establece una escala de pronóstico neuropsicológico que permite establecer criterios de priorización en el ingreso de pacientes en las unidades de epilepsia.
Pharmaco-refractory epilepsy in childhood produces significant cognitive deficits and psychoemotional disability due to both, the seizures themselves and the side effects of antiepileptic drugs. The factors that are related to a greater or lower degree with the cognitive disability of these patients are the age of onset of epilepsy, the location of the epileptogenic area and the time of evolution, among others. When making a diagnosis and weighting possible treatments and their complications, it is very important to be able to establish an accurate prognostic of the patient’s neuropsychological evolution. Based on the above, the main objective of the study is to define neuropsychological prognostic factors in children with refractory epilepsy. The present work studies a sample of 81 paediatric patients with refractory, focal and lesional epilepsy admitted to the Epilepsy Unit of the Hospital Sant Joan de Déu in Barcelona between 2005 and 2017. Based on the neuropsychological profile of the patients, defined from their main cognitive functions in childhood, 3 subpopulations are established similar at the neuropsychological level. By means of the factorial analysis, 3 factors are formed that explain 66% of the clinical variability of the sample: Global cognitive, Language and speed of information processing, and Affective symptoms and behaviour problems. The variables that have more incidence in the conformation of the factors are the age of onset of epilepsy, the time of evolution, the age at admission and the aetiology. From the correlation of these populations with the aforementioned factors, we extract the main clinical and sociodemographic variables that define the different cognitive profiles. This study proposes a neuropsychological prognostic scale that allows establishing prioritization criteria in the admission of patients to epilepsy units.
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Militzer, Arne [Verfasser], and Joachim [Akademischer Betreuer] Hornegger. "Boosting Methods for Automatic Segmentation of Focal Liver Lesions / Arne Militzer. Gutachter: Joachim Hornegger." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2015. http://d-nb.info/1075480299/34.
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Bakas, Spyridon. "Computer-aided localisation, segmentation and quantification of focal liver lesions in contrast-enhanced ultrasound." Thesis, Kingston University, 2014. http://eprints.kingston.ac.uk/30592/.
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The research presented in this thesis focuses on applications of Contrast Enhanced Ultrasound (CEUS) imaging and is coordinated to address current clinical requirements in the assessment, quantification and evaluation of liver cancer and in particular focal liver lesions (FLLs). The main outcomes of this research are methods to assist radiologists with automating these routinely performed manual image interpretation tasks, with the intention of supporting them to make their diagnostic decisions faster, more easily and with greater confidence. Such automatic analysis is challenging mainly because of the relative motion between the ultrasound transducer and the liver, the physiological motion of the patient and the dramatic intensity changes over time caused by the contrast-enhancing agents intravenously injected during a CEUS examination. The work described in this thesis can be divided into three principal themes. These are addressed in turn below. Firstly, a set of methods are proposed to assist in automating initialisation tasks required for the offline assessment of data acquired during CEUS liver scans. These tasks relate to the delineation of the area comprising the ultrasonographic image, the identification of the optimal reference frame for initialising an FLL, as well as the segmentation of the FLL boundaries on this frame. The potential clinical value of the proposed methods is that they can lead to easier and faster assessment of FLLs, whilst producing results less dependent on the human initialisation and hence improving the repeatability and reproducibility of the assessment of the examination and increasing the confidence of radiologists when making a diagnosis. Secondly, a variety of methods are investigated to estimate the motion observed within the ultrasonographic image of CEUS screening recordings and then compensate for this, allowing for an accurate quantification of the perfusion of tissue regions. Obtaining a perfusion curve for an image region, without compensating for the observed motion, may lead to erroneous diagnostic results as the specified image region may correspond to different tissue along the video sequence. Quantitative evaluation of the presented methods demonstrates their potential as reliable real-time motion compensation methods for such recordings. Finally, an alternative fully automatic method for the identification and localisation of potential malignancies is proposed. For such identification, and hence distinction between cases that include potentially malignant and benign lesions, an innovative assessment of the global spatial configuration of local variations of perfusion curves is presented. For the localisation of tissue regions of potential malignancy, a novel feature is proposed that encompasses spatio-temporal information (Le. the combination of both the variation in these local perfusion curves and the location they relate to) to cluster together neighbouring regions with similar dynamic behaviour. The clinical value of the identification part is the early diagnosis of an FLL’s type and the possibility for the discharge of patients with benign FLLs, leading to less distress to the patients and their families, as well as reduced healthcare costs. Additionally, the localisation part assists in enhancing the radiologist’s awareness of tissue regions with potentially malignant behaviour, as well as providing effortless localisation of such regions allowing for an objective initialisation of computer-aided segmentation methods improving the repeatability and reproducibility of the assessment of CEUS data. The key findings of this research indicate that: i) the optimal reference frame can be reliably identified in a fully automatic and deterministic manner, ii) the segmentation of an F LL can be performed in a rapid semi-automatic manner, which produces results that are, at worst, of comparable consistency as different manual annotations, iii) the apparent observed motion can be compensated in real-time, either locally or globally, and a simple translation is sufficient to achieve this, iv) the distinction between benign and malignant lesions can be performed in a fully automatic and deterministic manner, without missing a single malignancy, and v) potential malignancies can be localised reliably in a fully automatic manner. Quantitative analysis of all results on real clinical data, from a multi-centre study, is used to evaluate the level of confidence of the decision of the proposed methods and demonstrates the value of these methods in a diverse dataset acquired using the protocol of current standard care. A system incorporating the proposed methods could improve the current clinical practice for assessing, quantifying and evaluating FLLs in CEUS recordings. Specifically, it would be beneficial to radiologists, for cancer research, providing easier and faster assessment of FLLs whilst producing results less dependent on the human initialisation and therefore increasing the confidence of radiologists in their diagnostic decisions.
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ZAPPA, MAGALY. "Apport de l'irm dynamique dans l'etude du genou normal et des lesions osseuses focales de l'enfant." Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX20827.
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Milidonis, Xenios. "Multicentre evaluation of MRI variability in the quantification of infarct size in experimental focal cerebral ischaemia." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28877.
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Ischaemic stroke is a leading cause of death and disability in the developed world. Despite that considerable advances in experimental research enabled understanding of the pathophysiology of the disease and identified hundreds of potential neuroprotective drugs for treatment, no such drug has shown efficacy in humans. The failure in the translation from bench to bedside has been partially attributed to the poor quality and rigour of animal studies. Recently, it has been suggested that multicentre animal studies imitating the design of randomised clinical trials could improve the translation of experimental research. Magnetic resonance imaging (MRI) could be pivotal in such studies due to its non-invasive nature and its high sensitivity to ischaemic lesions, but its accuracy and concordance across centres has not yet been evaluated. This thesis focussed on the use of MRI for the assessment of late infarct size, the primary outcome used in stroke models. Initially, a systematic review revealed that a plethora of imaging protocols and data analysis methods are used for this purpose. Using meta-analysis techniques, it was determined that T2-weighted imaging (T2WI) was best correlated with gold standard histology for the measurement of infarctbased treatment effects. Then, geometric accuracy in six different preclinical MRI scanners was assessed using structural phantoms and automated data analysis tools developed in-house. It was found that geometric accuracy varies between scanners, particularly when centre-specific T2WI protocols are used instead of a standardised protocol, though longitudinal stability over six months is high. Finally, a simulation study suggested that the measured geometric errors and the different protocols are sufficient to render infarct volumes and related group comparisons across centres incomparable. The variability increases when both factors are taken into account and when infarct volume is expressed as a relative estimate. Data in this study were analysed using a custom-made semi-automated tool that was faster and more reliable in repeated analyses than manual analysis. Findings of this thesis support the implementation of standardised methods for the assessment and optimisation of geometric accuracy in MRI scanners, as well as image acquisition and analysis of in vivo data for the measurement of infarct size in multicentre animal studies. Tools and techniques developed as part of the thesis show great promise in the analysis of phantom and in vivo data and could be a step towards this endeavour.
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Barreto-Acevedo, Elliot, Mirla Villafuerte-Espinoza, Alicia Becerra-Zegarra, Alberto Díaz-Vásquez, José Hernández-Vizarreta, and Victoria Llaja-Rojas. "Cirugía resectiva de epilepsia lesional focal: Estudio en pacientes adultos del Seguro Social del Perú." Facultad de Medicina de la Universidad Peruana Cayetano Heredia, 2017. http://hdl.handle.net/10757/622322.
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Objetivos: Reportar la experiencia en cirugía resectiva en una serie de pacientes adultos con epilepsia focal lesional tratados en un hospital del Seguro Social del Perú. Material y Métodos: Se revisó la información registrada en la Unidad de Epilepsia de Adultos del Hospital Rebagliati, en Lima, desde enero del 2012 hasta octubre del 2016, sobre características clínicas, electrográficas, de neuroimagen y quirúrgicas de todos los pacientes con epilepsia focal lesional farmacorresistente, en los cuales se efectuó cirugía resectiva de epilepsia. La eficacia del procedimiento fue valorada mediante la Escala de Engel. Resultados: Se describen los resultados de cinco pacientes,proveyéndose información pertinente respecto a historia de la enfermedad, diagnósticos precisos, procedimientos quirúrgicos, seguimiento y complicaciones neurológicas y psiquiátricas. Conclusiones: La cirugía de epilepsia resectiva, basada en un trabajo multidisciplinario es reportada por primera vez en esta pequeña serie, demuestra ser eficaz y segura en adultos con epilepsia refractaria tratados en el Seguro Social del Perú.Objectives:To report the experience of resective surgery in a series of adult patients with lesional focal epilepsy seen in a hospital of Peru’sSocial Security system. Material and Methods:Data of the Adult Epilepsy Unit at Rebagliati Hospital in Lima, from January 2012 to October 2016 were reviewed. Information was obtained about clinical, electrographic, neuroimaging and surgical procedures of all patients with refractory lesional focal epilepsy, in whom resective epilepsy surgery was performed. Efficacy was evaluated using the Engel scale. Results: Analytic data of five patients with pertinent details regarding clinical history, diagnostic work-up, surgical procedures, follow-up and neurological and psychiatric complications, are presented and discussed. Conclusions: Resective epilepsy surgery, based on a multidisciplinary work and reported in this small first sample appears to be effective and safe in adults with refractory epilepsy seen in a Social Security facility from Peru.
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Reber, Justin. "Putting the “pseudo” back in pseudopsychopathy: assessing psychopathic traits in individuals with focal brain lesions." Diss., University of Iowa, 2019. https://ir.uiowa.edu/etd/6840.
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Damage to the ventromedial prefrontal cortex (vmPFC) can lead to disturbances in personality, emotional dysregulation, impairments in social conduct, and difficulties in decision-making. Many researchers have likened the conduct of individuals with vmPFC lesions to that of criminal psychopaths, labeling the effects of vmPFC damage “pseudopsychopathy” or “acquired sociopathy.” However, although psychopathy—a condition marked by a distinct mosaic of antisocial personality traits and behaviors—has been studied and characterized as a psychological and behavioral disorder by many researchers, the overlap between acquired sociopathy and psychopathy remains ambiguous. This study assessed the severity of psychopathic personality traits in neurological patients with acquired damage to the vmPFC using both informant-report and self-report measures.
On both informant-report and self-report measures, individuals with vmPFC damage showed no significant elevations across a wide range of psychopathic traits relative to demographically-matched neurologically healthy comparison participants and patients with damage outside of the vmPFC. The results showed only one trait, Fearlessness, that was significantly higher in patients with vmPFC lesions relative to the neurologically-healthy comparison group.
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Lemaire, Olivier. "Contribution a l'etude des proprietes biologiques des rna du virus de la rhizomanie (beet necrotic yellow vein virus) et de leur role dans l'etiologie de la maladie." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13115.
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Salling, Michael C. "The effects of fluoxetine and environmental enrichment on recovery of function following focal dentate gyrus lesions." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-2/sallingm/michaelsalling.pdf.
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Xiong, Zhou. "Factors determining the sensitivity of Staphylococcus aureus to the bactericidal lipids produced by the host in focal lesions /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487858417982086.
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CARVALHO, Walther Augusto de. "Ajustes motores compensatórios após lesão isquêmica focal unilateral do trato corticoespinhal." Universidade Federal do Pará, 2017. http://repositorio.ufpa.br/jspui/handle/2011/9526.
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O objetivo deste trabalho foi desenvolver um novo modelo de lesão química da medula espinhal causada por isquemia transitória focal e unilateral após microinjeção de endotelina-1 (ET1) no funículo dorsal e avaliar as alterações sensório-motoras da pata anterior de ratos (Wistar). Dos cinquenta (n = 50) animais (CEPAE/UFPA protocolo BIO0079-12), que foram treinados, trinta e três (n = 33) foram selecionados para compor os grupos controle (n = 15), sham (n = 6) e lesão (n = 12). Pelo uso de micropipeta foi injetado a profundidade de 1 mm a partir da superfície pial da medula espinhal o volume de 250 nL de solução salina (sham) ou ET-1 (lesão) próximo à artéria dorsal média da medula espinhal, no segmento cervical C4. A ET-1 provocou formação de cavidade cística amórfica de 0,421 mm2 ( 0,035 mm2 , n=3) sobre o trato corticoespinhal e substância branca suprajacente, ipsilateral ao sítio de microinjeção que pode ser medido em cortes transversais (50 m) corados pela técnica de Nissl. As funções motoras das patas anteriores foram avaliadas por testes sensório-motores específicos antes e após lesão em 3, 7 e 14 dias. Os resultados foram avaliados pelo teste estatístico ANOVA com análise post-hoc de Tukey ( = 0,05). Os resultados mostram, através do teste do manuseio do macarrão, que após a lesão ocorre um comportamento motor de compensatório onde a pata não-preferencial assume as funções da pata preferencial. O teste do “Staircase” revelou decréscimo da capacidade apreensão do objeto com a pata preferencial e o teste de extensão da pata mostrou que houve diminuição da sensibilidade.
The aim of this work was to develop a new model of spinal cord injury caused by focal and unilateral transient ischemia after ET-1 microinjection in the dorsal funiculus and to evaluate the sensorimotor alterations of the anterior paw of rats (Wistar). Fifty (n = 50) animals (CEPAE / UFPA protocol BIO007912), who were trained, thirty-three (n = 33) were selected to compose control (n = 15), sham (n = 6) and injury (n = 12) groups. By using a micropipette, we injected the volume of 250 nL of saline (sham) or endothelin-1 (lesion) near the medial dorsal artery of the cervical segment C4 at a depth of 1 mm from the pial surface of the spinal cord. ET-1 induced cystic cavity formation of 0.421 mm2 (± 0.035 mm2, n = 3) on the corticospinal tract and suprajacent white matter, ipsilateral to the microinjection site that can be measured in cross-sections (50 μm) stained by the Nissl technique. The motor functions of the forepaw were evaluated by specific sensorimotor tests before and after injury at 3, 7 and 14 days. The results were evaluated by the ANOVA statistical test with Tukey post-hoc analysis (α = 0.05). Our results show in pasta test that after injury there is a compensatory motor behavior in which the non-preferential forepaw assumes the functions of the preferential forepaw. The Staircase test revealed a decrease in the ability to grasp the object with the preferred paw and the Contact test showed a decrease in sensitivity of the preferred paw.
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Halavaara, Juha. "Magnetic resonance imaging of focal liver lesions : characterization with the spin lock technique and detectability with tissue-specific contrast agents." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/laa/kliin/vk/halavaara/.
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Weckerly, Jill. "Morphosyntactic ability and word fluency in atypically developing children : evidence from children with specific language impairment and children with early focal lesions /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9975030.
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Forner, González Alejandro. "Actitud a seguir ante la detección de una lesión focal inferior o igual a 2 cm de tamaño en un paciente con cirrosis hepática." Doctoral thesis, Universitat de Barcelona, 2010. http://hdl.handle.net/10803/2296.
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ANTECEDENTES: El diagnóstico precoz del carcinoma hepatocelular es la única opción para poder aplicar tratamientos radicales potencialmente curativos. Por este motivo es necesario desarrollar diferentes técnicas que permitan realizar el diagnóstico precoz.HIPÓTESIS: La vascularización predominantemente arterial del CHC determina un patrón vascular específico caracterizado por intensa captación de contraste en fase arterial seguida de lavado de contraste en fase venosa. De acuerdo a unos criterios propuestos por la AASLD y basados en opinión de expertos, es posible realizar el diagnóstico concluyente de CHC sin necesidad de confirmación histológica si se objetiva este patrón vascular mediante técnicas de imagen dinámicas (RM, TC y eco con contraste (US-C)). En el caso de nódulos entre 1 y 2 cm se recomienda demostrar este patrón de forma coincidente en dos pruebas dinámicas.
OBJETIVOS: Determinar la capacidad diagnóstica de la RM de última generación y US con contrastes de segunda generación para el diagnóstico de lesiones con un tamaño < 2 cm en pacientes con cirrosis hepática, con especial énfasis en el diagnóstico diferencial con el colangiocarcinoma intrahepático. Asimismo, como segundo objetivo se evaluará el valor de la captación de contraste para determinar la respuesta tumoral tras la aplicación de tratamientos locorregionales.
METODOLOGÍA: Estudio observacional prospectivo en el que se incluirán pacientes cirróticos con función hepática conservada y sin historia previa de CHC en los que se detecta un nódulo único de 5-20 mm por ecografía de screening. Se realizará de forma basal una RM dinámica, US-C, determinación de marcadores tumorales y una biopsia, que se repetirá en caso de diagnóstico negativo. En caso de ausencia de malignidad, se realizará un seguimiento mediante US-C/3m y RM/6m; ante la detección de crecimiento o cambio de vascularización se realizará nueva biopsia. En la segunda parte del estudio se evaluará de forma retrospectiva la respuesta tumoral de una cohorte de pacientes afectos de CHC tratados mediante tratamientos locorregionales (ablación percutánea o quimioembolización) teniendo en cuenta criterios convencionales (medición de diámetros; criterios RECIST) o evaluando la extensión de necrosis reconocida como áreas sin captación de contraste.
RESULTADOS: El diagnóstico de CHC puede establecerse en nódulos <20 mm sin necesidad de una biopsia positiva si US-C y RM muestran de forma coincidente hipercaptación en fase arterial seguido de lavado en fase venosa. La presencia de lavado de contraste permite el diagnóstico diferencial con el colangiocarcinoma intrahepático (ICC). Los criterios RECIST evalúan erróneamente la eficacia de los tratamientos locorregionales e infraestiman los beneficios de los tratamientos locorregionales.
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Queiroz, Antônio Altenor Bessa de [UNIFESP]. "Lesão focal cartilaginosa do joelho comparando as técnicas de implante de hidrogel com transplante osteocondral autólogo. Ensaio clínico randomizado." Universidade Federal de São Paulo (UNIFESP), 2015. http://repositorio.unifesp.br/handle/11600/39301.
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Introdução: A escolha do tratamento para os pacientes diagnosticados com lesão focal cartilaginosa da articulação do joelho representa uma decisão difícil, e até o momento, não há estudo clínico randomizado envolvendo o Hidrogel (Cartiva™). Objetivo: avaliar e comparar os resultados dos procedimentos Hidrogel (Cartiva™), e o transplante osteocondral autólogo (TOA) no tratamento das lesões focais cartilaginosas da articulação do joelho. Métodos: Num total de 38 pacientes, 38 joelhos, com sintomas de dor e lesão da cartilagem articular graus III ou IV de Outerbridge, foram randomizados para dois grupos iguais. O Grupo I, submetido ao transplante osteocondral autólogo e, o Grupo II, ao tratamento com implante de Hidrogel. Os pacientes foram avaliados pré e pós-operatoriamente aos seis meses, 12 meses e 24 meses, utilizando o IKDC subjetivo, EVA (escala visual analogia da dor), ADLS (Activities of Daily Living Scale) e escala de Lysholm. Resultados: Utilizando a média de pontuação dos questionários foi possível a avaliação final, analisando os resultados dentro do próprio grupo, e entre os grupos, comparados o pré e o pósoperatório. Os dois grupos melhoraram e foram estatisticamente significante (p ≤ 0,05), porém não houve diferença entre os grupos. Quanto às complicações, tivemos sintomas de dor prolongada em quatro (10,5%) pacientes, sendo dois de cada grupo, com regressão dos sintomas na avaliação de um ano. Conclusão: Os dois grupos apresentaram melhora, estatisticamente significante, e não houve superioridade de um sobre o outro. O implante de Hidrogel mostrou-se seguro, e a técnica, permite boa relação de estabilidade e função articular, num seguimento de dois anos.
Introduction: The choice for treating patients diagnosed with a focal chondral defect in the knee joint represents a difficult decision. To date, there has been no randomized controlled trial involving Hydrogel (CartivaTM). Objective: To evaluate and compare the results of the Hydrogel (CartivaTM) and the Osteochondral Autologous Transplantation (OAT) procedures for treating a focal chondral defect of the knee joint. Methods: From the total of thirty-eight (38) patients and thirty-eight (38) knees, showing pain symptoms and articular cartilage lesion at grades III or IV under the Outerbridge classification, two equal groups were randomized. Group I was submitted to Osteochondral Autograft Transplantation (TOA), while Group II underwent a Hydrogel implant. The patients were examined before and after the procedures, then respectively six, 12 and 24 months later, using the subjective IKDC score, the Visual Analogue Scale (VAS), Activities of Daily Living Scale (ADLS) and the Lysholm Knee Scoring Scale. Results: The final outcome was reached by using the average score of the questionnaire, and analyzing the results in the group itself and between groups by comparing the pre and postprocedure step. Both groups improved and were statistically significant (p < 0,05), however showing no difference between them. As for complications, we observed symptoms of long-lasting pain in four patients (10.5%) with two patients in each group showing a decrease in symptoms over a one-year evaluation period. Conclusions: Both groups had a statistically-significant improvement and none was higher than the other. The Hydrogel implant has proved to be safe and the technique has allowed a good stability and joint function relation over a two-year follow-up.
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Beaudenon, Sylvie. "Clonage moleculaire et caracterisation du genome de quatre papillomavirus humains associes a des lesions benignes ou a des neoplasies des muqueuses." Paris 6, 1988. http://www.theses.fr/1988PA066048.
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Taniguchi, Leandro Utino. "Avaliação imunohistoquímica das alterações do citoesqueleto na parede alveolar em modelo experimental de lesão pulmonar induzida pela ventilação mecânica em ratos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5159/tde-07122009-180201/.
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INTRODUÇÃO: A ventilação mecânica é uma terapia importante, mas com possíveis complicações. Uma das mais relevantes é a lesão pulmonar induzida pelo ventilador (VILI do inglês Ventilator-induced lung injury). Devido à hiperdistensão alveolar, o pulmão inicia um processo inflamatório, com infiltrado neutrofílico, formação de membrana hialina, fibrogênese e prejuízo de troca gasosa. Nesse processo, a mecanotransdução do estímulo da hiperdistensão celular se faz através do citoesqueleto da célula e de suas interações com a matriz extracelular e com as células vizinhas. Apesar desse papel fundamental no processo da VILI, não existem estudos in vivo sobre as alterações do citoesqueleto e de suas proteínas associadas durante esse processo patológico. O objetivo desse estudo foi descrever as alterações no citoesqueleto e em duas de suas principais proteínas associadas (FAK e paxilina) durante esse processo. MÉTODOS: Nesse estudo experimental foram feitos três grupos (n = 4 6): um controle e dois ventilados por quatro horas com PEEP de 5 cmH2O. Um grupo foi ventilado com volume corrente de 8 ml/kg (BV) e o outro com 24 ml/kg (AV). Dados de mecânica respiratória foram calculados no início e no final do período experimental. Os pulmões foram avaliados por histomorfometria quanto à área proporcional de parênquima, índice de infiltrado neutrofílico e índice de edema perivascular, quanto à quantidade de fosfo-FAK, fosfo-paxilina, paxilina total, actina músculo liso e alfa-tubulina por Western Blot, quanto à imunofluorescência para paxilina total com microscopia confocal a laser e com microscopia eletrônica de transmissão. RESULTADOS: os grupos foram semelhantes nas características basais. Houve aumento da elastância dinâmica (Edin) no grupo BV e redução no grupo AV (Edin inicial e final: 0,76 ± 0,4 vs 1,02 ± 0,47 respectivamente, em cmH2O/ml; p = 0,001). Não houve diferença na área proporcional de parênquima ou índice de edema perivascular entre os grupos estudados. A ventilação mecânica induziu infiltrado neutrofílico pulmonar nos animais, tanto no grupo BV como no AV em relação ao controle (p < 0,001). O infiltrado foi mais importante no grupo AV que no BV (p = 0,003). Houve um aumento de 40% na fosfo-FAK pelo Western Blot no grupo AV em relação ao controle (p=0,069) e aumento significativo de fosfo-paxilina no grupo AV em relação ao controle (p<0,001) e ao BV (p<0,001). Não se observaram diferenças para paxilina total, actina músculo liso e alfa-tubulina. A microscopia confocal demonstrou marcação para paxilina total nos septos alveolares. A microscopia eletrônica sugeriu reorganização do citoesqueleto nas zonula adherens do grupo AV. CONCLUSÕES: A ventilação mecânica promove lesão pulmonar com infiltrado neutrofílico numa relação dose-dependente. A ventilação com alto volume corrente promove fosforilação da FAK e de paxilina. As alterações no citoesqueleto em modelo in vivo de VILI são possíveis de serem descritas utilizando-se de métodos de microscopia confocal, Western Blot e microscopia eletrônica.INTRODUCTION: Mechanical ventilation is an important therapy, but is associated with complications. One of the most relevant is ventilator-induced lung injury (VILI). Due to alveolar hyperdistension, the lung initiates an inflammatory process, with neutrophilic infiltration, hyaline membrane formation, fibrogenesis and gas exchange impairment. In this process, cellular mechanotransduction of the overstretching stimulus is mediated through the cytoskeleton and its cell-cell and cell-matrix interactions. But, although the cytoskeleton has this important role in the pathogenesis of VILI, there are no in vivo models for the research of cytoskeletal and cytoskeleton-associated proteins modifications during this pathological process. Our objective was to describe the immunohistochemical modifications during this process on the cytoskeleton and on two of its associated proteins (FAK and paxillin). METHODS: in this experimental study, three groups (n = 4 6) were studied: a control group and two ventilated for four hours with PEEP of 5 cmH2O. One group was ventilated with tidal volume of 8 mL/kg (LV) and the other with 24 mL/kg (HV). Data of respiratory mechanics were obtained at the beginning and the end of the experimental period. The lungs were evaluated with histomorphometry for parenchymal proportional area, neutrophilic infiltrate and perivascular edema, with Western Blot for phospho-FAK, phospho-paxillin, total paxillin, alpha-smooth muscle actin and alpha-tubulin, with confocal laser scanning microscopy for total paxillin, and with transmission electron microscopy. RESULTS: the groups were similar at the baseline. Dynamic elastance (Edin) increased in LV group and decreased in HV group (Edin initial to final: 0.76 ± 0.4 vs. 1.02 ± 0.47 respectively, in cmH2O/ml; p = 0.001). There was no difference in the parenchymal proportional area or the perivascular edema in the three groups. Mechanical ventilation induced pulmonary neutrophilic infiltration, both in the LV group and the HV group in comparison with control (p < 0.001). The infiltrate was more important in the HV group than in the LV group (p = 0.003). Phospho-FAK increased 40% in the HV group in Western Blot in comparison with control (p=0.069). Phosphopaxillin increased significantly in HV group compared with control (p<0.001) and with LV (p<0.001). Total paxillin, alpha-smooth muscle actin and alpha-tubulin did not show any differences. Confocal microscopy showed total paxillin labeling at alveolar septa. Electron microscopy suggested cytoskeleton reorganization at the zonula adherens in the AV group. CONCLUSIONS: Mechanical ventilation induces pulmonary injury with neutrophilic infiltrate in a dose-dependent relationship. Ventilation with high tidal volume promotes FAK and paxillin phosphorilation. The alterations in cytoskeleton in an in vivo model of VILI are possible to be studied with confocal microscopy, Western Blot and electron microscopy.
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Demain, Boris. "Preuve de concept d'une stratégie thérapeutique avec des neuro-implants microstructurés dans un nouveau modèle de lésion cérébrale focale chez le marmouset." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30347/document.
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Introduction : L'Accident Vasculaire Cérébral (AVC) est la 1ère cause de handicap acquis chez l'adulte, dans les pays industrialisés. 20% des patients décèdent dans le mois qui suit, 75% des survivants gardent des séquelles définitives, 33% deviennent dépendant à vie. Il n'existe pour l'heure aucune thérapie de récupération quand les déficits fonctionnels sont en place hormis la rééducation. Chez l'homme, 80% des AVC thrombotiques touchent l'artère cérébrale moyenne, qui irrigue le cortex moteur primaire (M1). M1 projette des axones jusque dans la moelle épinière et forme le Faisceau Cortico Spinal (FCS). Après une atteinte de M1, ce faisceau dégénère et cela induit des déficits fonctionnels de force et de dextérité. M1 est indispensable pour les mouvements volontaires dextres garants de l'indépendance du patient. Objectif : Mise au point d'un modèle de lésion cérébrale, chez un primate non humain, le marmouset, qui permette d'évaluer la récupération fonctionnelle motrice afin d'étudier l'effet de neuro-implants. Méthode : 14 marmousets ont servi à caractériser le nouveau modèle lésionnel induit par une injection stéréotaxique d'une toxine inhibant le métabolisme cellulaire. Des tests comportementaux, évaluant le score neurologique, la dextérité et la force de traction du membre supérieur, ont permis d'évaluer la récupération fonctionnelle en phase aiguë, subaiguë et chronique jusqu'à 6 mois après la lésion. Le suivi longitudinal structural et fonctionnel de la lésion et de la récupération a été réalisé par IRM (T1, T2, DTI). Le suivi de l'intégrité du FCS a été étudié, pour la première fois chez le marmouset, grâce à une technique (ME-MRI, manganese-enhanced-MRI) utilisant un agent de contraste injecté directement dans le cortex M1, capté par les neurones et traçant les voies neuronales. Une étude pilote sur 3 marmousets a testé l'effet de neuro-implants microstructurés dans la lésion cérébrale associés à l'injection de chondroïtinase ABC (enzyme de dégradation de la matrice extracellulaire)Introduction: Stroke is the first leading cause of acquired handicap and disability in adults in industrialized countries. 20% of patients die in the following month, 75% of survivors remain with definitive sequelae, 33% become dependent for life. No therapy in the recovery phase exists today when functional deficits are installed except rehabilitation. In human, 80% of thrombotic stroke affect middle cerebral artery, which supplies the primary motor cortex (M1). M1 projects axons to the spinal cord and forms the CorticoSpinal Tract (CST). After an M1 insult, this tract degenerates and functional deficits of force and dexterity are induced. M1 is essential for voluntary dexterous movements that make patients independent. Objective: Setting up of a cerebral lesion model in a non-human primate, the marmoset, where the functional motor recovery can be assessed in order to study thereafter the effect of neuro-implant. Methods: 14 marmosets served to characterize the new lesion model induced by stereotaxic injection of a toxin inhibiting the cellular metabolism. Behavioral tests assessing the neurological score, dexterity and pulling strength of the upper limb, could assess the functional recovery in the acute, sub-acute and chronic phases until 6 months after the lesion. The longitudinal structural and functional follow-up after the lesion and during the recovery was done with MRI (T1, T2, EPI, DTI). The follow-up of the integrity of the CST was studied for the first time in the marmoset with a technic (ME-MRI, manganese-enhanced-MRI) using a contrast agent injected directly in the cortex M1, taken up by neurons and that traced neuronal tracts. A pilot study on 3 marmosets tested the effect of micro-patterned neuro-implants in the cerebral lesion associated with the injection of chondroïtinase ABC (enzyme of extracellular matrix degradation)
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Žvinienė, Kristina. "Ultragarsinio tyrimo ir kompiuterinės tomografijos palyginamoji vertė diagnozuojant pavienius židininius kepenų pakitimus." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20090504_155626-53514.
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Židininiai kepenų pakitimai (ŽKP) – vieni dažnesnių patologinių radinių tiriant pacientus dėl įvairių virškinimo ar kitų organizmo sistemų ligų. Įvairių spindulinės diagnostikos metodų dėka nustačius patologinius židinius kepenyse ypač svarbi jų klinikinė diferencinės diagnostikos reikšmė. ŽKP diferencinės diagnostikos esmė yra kiek įmanoma tikslesnis židinio kepenyse kraujotakos nustatymas ir aprašymas. Šios problemos sprendime naujų galimybių įgyja santykinai nauja ir Lietuvoje niekur kitur dar neatliekama UG tyrimo su i/v kontrastavimu metodika, kurios metu gaunami rezultatai lyginami su dominuojančių įprastų KT ir MRT kontrastinių tyrimų rezultatais. Tikslas: nustatyti radiologinių tyrimų vertę diagnozuojant židininius kepenų pakitimus (ŽKP) Uždaviniai: 1. Nustatyti įprastinio UG, UG su i/v kontrastavimu ir KT su i/v kontrastavimu diagnostikos metodų tikslumo rodiklius nepiktybiniams ir piktybiniams ŽKP. 2. Nustatyti UG ir KT su i/v kontrastavimu vertingiausius diagnostikos kriterijus vertinant židininių kepenų pokyčių prigimtį. 3. Palyginti tarpusavyje UG ir KT su i/v kontrastavimu nustatytų židininių kepenų pakitimų diagnostikos metodų tikslumo rodiklius nepiktybiniams ir piktybiniams ŽKP. 4. Įvertinti kepenų hemangiomų radiologinių diagnostikos metodų tikslumo vertę.Focal hepatic lesions (FHL) are one of the most common pathological findings in patients who are examined for gastrointestinal or other diseases. The rigorous description of blood circulation in the hepatic focus is essential in differential diagnosis of FHL. US with i/v contrast enhancement is a new imaging method enabling definition of nature of FHL, follow-up, treatment efficacy and monitoring for possible relapse of the process. This study is conducted solely in the Radiology Department of Kaunas University of Medicine Hospital. Aim of the study To evaluate and compare the value of ‘bolus’ contrast-enhanced CT and contrast-enhanced US in diagnostics of focal hepatic lesions. Tasks of the study 1. To determine rates of diagnostic accuracy of conventional US, US with i/v contrast enhancement and ‘bolus’ contrast-enhanced CT in diagnosis of benign and malingnant FHL. 2. To establish the main and most effective diagnostic criteria of US and CT with i/v contrast enhancement for the assessment of nature of focal hepatic lesions. 3. To compare rates of diagnostic accuracy of US with i/v contrast enhancement and ‘bolus’ contrast-enhanced CT in diagnosis of benign and malingnant FHL. 4. To assess the reliability of radiological diagnostics of hemangioma, comparing the results of US, CT, and MRI.
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Abud, Lucas Giansante. "Análise quantitativa por ressonância magnética da epilepsia parcial sintomática de difícil controle com imagem qualitativa negativa para lesão epileptogênica." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17140/tde-23042018-141223/.
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A RM convencional de rotina pode ser inconclusiva a cerca de um terço dos pacientes com epilepsia parcial (focal) refratária. Esses pacientes com RM negativa, quando indicados para cirurgia, representam um grande desafio, visto que a identificação de uma lesão estrutural epileptogênica por esse método pode ser considerada o melhor fator prognóstico para eliminação das crises no período pósoperatório. O objetivo foi avaliar o rendimento e a utilidade da RM quantitativa por meio de pós-processamentos individualizados nesse grupo de pacientes. Trata-se de um estudo prospectivo de uma coorte de 46 pacientes com epilepsia focal farmacorresistente com RM-3 Teslas não lesional e potenciais candidatos a cirurgia. Todos os pacientes foram submetidos a um novo protocolo de RM, incluindo 3D T1 e técnicas avançadas, e, posteriormente, avaliados por pós-processamentos individualizados de cinco medidas quantitativas extraídas dessas sequências. Essas medidas consistiram em espessura cortical (EC) e do sinal de junção entre as substâncias branca e cinzenta (JBC), ambas extraídas da sequência 3D T1, assim como da relaxometria T2 (RT2), taxa de transferência de magnetização (TTM) e difusibilidade média (DM). Os dados extraídos de todo o cérebro foram individualmente comparados com um grupo de controle saudáveis, utilizando-se das técnicas de análise baseada em superfície para a EC e de análises baseadas em voxel para as demais medidas. Utilizou-se do videoencefalograma de superfície e semiologia das crises para determinar a possível zona epileptogênica (ZE), sendo que 31 pacientes foram considerados como foco localizatório suspeito (FLS). As medidas quantitativas detectaram individualmente mudanças de sinal em alguma região do cérebro de 32,6% a 56,4% dos pacientes. No subgrupo classificado como FLS, os pós-processamentos detectaram individualmente alterações na região de origem eletroclínica das crises em 9,7% (3/31) a 31,0% (9/29) dos pacientes. Esse rendimento foi mais alto com a DM (31,0% ou 9/29) e RT2 (25,0% ou 7/28) e mais baixo com a EC e JBC (9,7% ou 3/31). Alterações observadas fora da região presumida da ZE foram sempre superiores, variando de 25,8% (8/31) a 51,7% (15/29). Em cinco pacientes (5/46 ou 10,9%) foi possível identificar alteração estrutural após a avaliação visual com direcionamento localizatório pelos pósprocessamentos. Embora a análise quantitativa da RM individualizada possa sugerir lesões ocultas no protocolo convencional, é preciso ter cautela devido à aparente baixa especificidade dos achados. Nesse grupo de pacientes, essas alterações devem refletir não só as alterações na região da ZE, mas também anormalidades microestruturais secundárias às crises ou, menos provavelmente, malformações cerebrais extensas não visíveis nos protocolos de rotina. Uma potencial utilidade prática desses métodos é auxiliar na colocação de eletrodos intracranianos em casos selecionados. Por outro lado, o estudo mostrou capacidade de detectar lesões potencialmente epileptogênicas que passaram despercebidas na inspeção visual convencional da RM após reavaliações dirigidas pelos pós-processamentos, notadamente pela medida da EC. Isso sugere que essas técnicas podem ser usadas como uma ferramenta de triagem para evitar que qualquer lesão visível seja ignorada ou a fim de guiar uma nova inspeção visual dirigida para uma região suspeita.Conventional MRI may be inconclusive in about one-third of patients with refractory partial epilepsy. These patients with negative MRI when indicated for surgery represent a great challenge since the identification of an epileptogenic structural lesion by this method can be considered the best prognostic factor for the elimination of the crises in the postoperative period. Our objective was to evaluate the yield and utility of quantitative MRI through individualized post-processing in this group of patients. The present thesis is a prospective study of a cohort of forty-six patients with drug-resistant partial epilepsy, with non-lesional 3-Teslas MRI and potential surgical candidates. All patients underwent a new MRI protocol, including 3D T1 and advanced techniques, and were subsequently evaluated through individualized post-processing of five quantitative measures extracted from these sequences. These measurements consisted of the cortical thickness (CT) and the signal between the white and gray matters junction (WGJ), both extracted from the 3D T1 sequence, as well as the T2 relaxometry (RT2), magnetization transfer rate (MTR) and mean diffusibility (MD). Data extracted from the whole brain were individually compared to a healthy control group using surface-based analysis (SBM) techniques for CT and voxel-based analyzes (VBA) for the other measures. Surface VEEG and seizure semiology were used to determine the possible epileptogenic zone (EZ). Consequently 31 patients were considered to have a suspect location for the Focus (SLF). Quantitative measurements individually detected abnormalities in some regions of the brain from 32.6% to 56.4% of patients. In the subgroup classified as FLS post-processing individually detected abnormalities inside the region of electroclinical origin of seizures in 9.7% (3/31) to 31.0% (9/29) of the patients. This yield was higher with MD (31.0% or 9/29) and RT2 (25.0% or 7/28) and lower with CT and WGJ (9.7% or 3/31). Abnormalities observed outside the presumed EZ region were always higher, ranging from 25.8% (8/31) to 51.7% (15/29). In five patients (5/46 or 10.9%) it was possible to identify some structural abnormality after the MRI visual inspection with orientation of the location by post-processing. Although the MRI quantitative analysis through individualized post-processing may suggest hidden structural lesions in the conventional protocol, caution should be exercised because of the apparent low specificity of theses findings for the EZ. In this group of patients these abnormalities should reflect not only the alterations in the EZ region, but also the microstructural abnormalities secondary to the seizures or less likely extensive cerebral malformations not visible in the routine protocols. A practical potential utility of these methods is to assist in the placement of intracranial electrodes in selected cases. On the other hand, the study showed a certain capacity to detect potentially epileptogenic lesions that became unnoticed in the MRI conventional visual analysis after re-evaluations directed by post-processing, notably by CT measurement. This suggests that these methods should be used either as a screening tool to prevent any visible lesions from being ignored or to guide a new visual inspection directed to a suspect region.
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Ramin, Sergio Luiz. "Espectroscopia de prótons por ressonância magnética: aplicação clínica em pacientes com lesões encefálicas focais." Faculdade de Medicina de São José do Rio Preto, 2003. http://bdtd.famerp.br/handle/tede/210.
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Previous issue date: 2003-11-21Proton magnetic resonance spectroscopy is an noninvasive method that allows the detection of metabolic and biochemical detection of areas of the brain. This investigation focused on the clinical applications of proton MR spectroscopy in patients with focal brain lesions, considering the possibility of differentiate the normal brain tissue of pathological, neoplasic of non-neoplasic disorders, brain neoplasms to each other and similar lesions identified by the magnetic resonance imaging. A total of 308 proton magnetic resonance spectroscopies in 287 patients with focal brain lesions, 147 (51.2%) males and 140 (48.8%) females, was divided into three groups: Group I - 169 exams of patients with brain neoplasic; Group II - 58 exams of patients with non-neoplasic focal brain lesions, and Group III - 32 exams of individuals without lesions. Single voxel proton MR spectroscopy with echo time 136 ms was the method used. The qualitative analysis of the peaks of metabolites N-acetyl aspartate (Naa - 2,0 ppm), creatine (Cr - 3,0 ppm) and choline (Cho - 3,2ppm), expressed in graph, and quantitative by means of the calculation of the ratios Naa/Cr, Co/Cr and Co/Naa through height measurement of the peaks in the graph. The statistical analysis included Kruskal-Wallis test and principal component analysis. In most of spectroscopies performed in patients of Group I, there was an accentuated increase of Cho peak and reduction of Naa; in Group II slight increase of Cho and decrease of Naa was observed, while in the individuals of Group III Naa was the larger peak, corresponding to the double of the height of the Cho and Cr peaks. Lipids (0.9 and 1.3 ppm), that generally indicate necrosis, was detected more usually in malignant neoplasms (multiforme glioblastoma and metastases) and inflammatory process by toxoplasmosis. Aminoacids (0.9 ppm inverted) were detected only in pyogenic abscesses. Median values of Naa/Cr, Co/Cr and Cho/Naa ratios in Group I were 0.75, 3.00, and 4.00; 1.13, 1.20, and 0.92 in Group II; and 2.00, 0.76, and 0.40 in group III, respectively. With the ratios studied, it was possible differentiate significantly the three groups (p<0.001). The clinical application of the proton MR spectroscopy is useful to the elucidation of the etiological diagnosis of focal brain lesions. Metabolic pattern obtained by proton spectroscopy is distinct between normal brain tissue and pathological, occurring significant difference between neoplasic of non-neoplasic disorders. Proton magnetic resonance spectroscopy contribute to differentiate focal brain lesions similar to the magnetic resonance imaging exam.
A espectroscopia de prótons por ressonância magnética é um método não invasivo que possibilita a detecção de alterações metabólicas e bioquímicas de áreas do encéfalo. Este estudo teve como objetivo avaliar a aplicação clínica da espectroscopia de prótons por ressonância magnética em pacientes com lesões encefálicas focais, considerando-se a possibilidade de diferenciar tecido encefálico normal do patológico, lesões neoplásicas de não neoplásicas, neoplasias encefálicas entre si e lesões similares identificadas pela imagem por ressonância magnética. Foram estudados prospectivamente 308 exames de espectroscopia de prótons por ressonância magnética em 287 pacientes com lesões encefálicas focais, sendo 147 do sexo masculino (51,2%) e 140 do feminino (48,8%). Os exames foram divididos em três grupos: Grupo I - 169 exames de pacientes com neoplasias encefálicas; Grupo II - 58 exames de pacientes com lesões encefálicas focais não neoplásicas e Grupo III - 32 exames como grupo controle. Para realização da espectroscopia de prótons por RM foi utilizado o método single voxel com tempo de eco de 136 ms. Foram feitas análises qualitativa do comportamento dos picos dos metabólitos N-acetilaspartato (Naa - 2,0 ppm), creatina (Cr - 3,0ppm) e colina (Co - 3,2 ppm), expressos em gráfico, e quantitativa por meio do cálculo das razões Naa/Cr Co/Cr e Co/Naa, efetuado com base na amplitude do pico. A análise estatística incluiu teste de Kruskal-Wallis e análise de componentes principais. Na maioria das espectroscopias feitas em pacientes do Grupo I, houve aumento acentuado do pico de Co e redução do pico de Naa, nos exames do grupo II, leve aumento Co e redução de Naa, enquanto nos indivíduos do Grupo III nos exames o pico de Naa sempre foi o maior, correspondendo ao dobro da altura dos picos de Co e Cr. O metabólito lipídios (0,9 e 1,3 ppm), que geralmente indica necrose, foi detectado mais comumente em neoplasias malignas (glioblastoma multiforme e metástases) e processo inflamatório por toxoplasmose. Os aminoácidos (0,9 ppm invertido) foram detectados exclusivamente em abscessos piogênicos. Os valores das medianas das razões Naa/Cr, Co/Cr e Co/Naa nos exames dos pacientes do grupo I foram 0,75, 3,00 e 4,00; no grupo II 1,13, 1,20 e 0,92 e no grupo III 2,00, 0,76 e 0,40, respectivamente. Com as razões estudadas, foi possível diferenciar significantemente os três grupos (p<0,001). A aplicação clínica da espectroscopia de prótons por ressonância magnética é útil para a elucidação do diagnóstico etiológico de lesões encefálicas focais. O padrão metabólico obtido pela espectroscopia de prótons é distinto entre tecido encefálico normal e patológico, havendo também diferença significante entre lesões neoplásicas e não neoplásicas. A espectroscopia de prótons por ressonância magnética contribui para diferenciar lesões encefálicas focais similares ao exame de imagem por ressonância magnética
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Chuang, Jia-Ying, and 莊佳穎. "A size-controllable focal striatal lesion produced by local injection of glutamate in rats." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/48497726076033329771.
Full textAbstract:
碩士慈濟大學
藥理暨毒理學研究所
94
Abstract Focal brain lesions, no mater produced by various cytotoxic agents or occlusion of cerebral artery, are primarily caused by excessive glutamate release. A controllable and reliable brain lesion size in the in vivo model was not available. Intra-striatal infusion of sodium glutamate (2-6 mmol at 1 M or 2 osm) produced dose-dependent increases in striatal lesion size as estimated with 2 % triphenyltetrazolium chloride (TTC) stain, in anesthetized male Sprague-Dawley rats (250-350 g). Although the same dose-induced lesion size varied widely in different rats, it varied very less on both sides of the same rat brain, while different dose-induced lesion sizes were markedly dose-dependent on both sides of the same rat brain. The lesion size was not significantly affected by osmotic effect of 1 M or 2 osm glutamate whose osmolarity is much higher than osmolarity (0.3 osm) of the extracellular fluid, because infusions of 2 osm glucose or NaCl produced but negligible lesions. Impairment of the behavior as evaluated by swing test, patch test, rotarod test, and rotational behavior test. The lesion-induced motor function impairment was improved by G-CSF administration. Applicability of this model in studying neuroprotective agents was attested by the findings that glutamate (4 mmol, 1 M)-induced striatal lesion was reduced by three neuroprotective agents, granulocyte colony-stimulating factor (G-CSF, 200 mg kg-1), a cytokine growth factor, and estradiol (2 mg kg-1), a female sex hormone, and an anti-inflammatory compound, oroxylin-A (30 mg kg-1). We thus developed a novel rat model in which local intra-striatal infusion of controlled doses of glutamate produced a controllable and reliable, striatal lesion size. This model is easy and convenient and may be important for application in studying neuroprotective agents.
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Chou, Chen-Te, and 周成德. "Characterization of focal liver lesion and detection of hepatocellular carcinoma: Utility of ferucarbotran-enhanced magnetic resonance imaging." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/10374140224809328500.
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博士國立陽明大學
生物醫學影像暨放射科學系暨研究所
98
HCC is also one of the leading causes of cancer death in patients with cirrhosis in Taiwan. A majority of HCC cases arise due to chronic hepatitis and cirrhosis. With advances in imaging diagnosis, hepatic nodular lesions are now frequent found during the course of chronic liver disease. Currently, treatment of HCC included liver transplantation, segmental liver resection, and percutaneous minimal invasive therapies. Regardless of the therapeutic modalities used, it is well known that the best results are obtained in patients with small, noninvasive tumors. Due to the “multistep” carcinogenesis in patient with chronic liver disease, it is important to determine which types of hepatic nodules are precancerous. SPIO is a tissue-specific MR contrast agent that is taken by Kupffer cells in the liver and macrophages in the spleen. Phagocytosed SPIO particles in the Kupffer cells produce strong T1, T2, and T2* relaxation effects in the liver parenchyma. Ideally, malignant tumors retain no Kupffer cells and exhibit no signal change, resulting in increased tumor-liver contrast, which can be exploited to decrease threshold size for lesion detection. But the diagnosis of well-differentiated HCCs can be problematic: with the evolution of HCCs from dysplastic nodules, the loss of number and function of Kupffer cells within the lesions is gradual rather than abrupt. Kawamori et al reported the usefulness of SPIO-enhanced MRI in the differentiation of HCC from hyperplastic nodules in a rat model. Imai et al also found SPIO contrast agent (ferumoxide)-enhanced MRI useful in predicting the histological grading of HCC, but not in differentiating dysplastic nodules from well-differentiated HCC. Ferucarbotran has a strong effect on the shortening of both T1 and T2 relaxation time. As a result, it reduces the signal intensity of liver parenchyma on T2- and T2*- weighted imaging and increases T1 signal intensity of hepatic tumors depending upon the tumor vascularity on dynamic T1-weighted imaging. It is difficult to detect borderline lesions and early-stage HCCs such as dysplastic nodules and well differentiated HCCs (wHCCs) using SPIO-enhanced MRI due to SPIO uptake by the retained Kupffer cell activity in the nodules. We tried to determine the value of PSIL threshold for differentiation between benign and malignant lesions in high-risk patients with chronic liver disease. In the study, ferucarbotran-enhanced FS-T2WI with a PSIL threshold of 40% for differentiation between HCC and benign hepatic nodules in patients with liver cirrhosis or chronic hepatitis is recommended. It is useful for distinguishing moderately and poorly differentiated HCC from benign nodules in these patients. We tried to investigate the usefulness of ferucarbotran-enhanced MRI in determining the histological grading of HCC and distinguishing HCC from hyperplastic nodules on the basis of signal intensity changes. We found that the use of ferucarbotran in MRI helped to differentiate various histologic grades of HCC but could not differentiate hyperplastic nodules from well differentiated HCC on T2-weighted imaging after calculating PSIL. Dynamic post-ferucarbotran contrast-enhanced T1-weighted images did not provide additional information about the histologic grade of HCC. In our practice, ferucarbotran-enhanced accumulation phase T1WI with fat suppression imaging could improve HCC detection and has not been investigated. We designed a study to evaluate the effectiveness of ferucarbotran-enhanced accumulation phase FS-T1WI when used as part of a HCC detection protocol. The postcontrast accumulation phase FS-T1WI could increase HCC detection due to better CNR and is recommended as part of the routine protocol for HCC detection. T1W hyperintense nodules against a background of cirrhosis are diagnostically challenging in daily practice. We designed a study to evaluate the ferucarbotran-enhanced MR imaging with accumulation-phase fat suppression T1-weighted imaging in comparison with gadolinium-enhanced MR imaging for characterization of T1W hyperintense nodules within cirrhotic liver. We found ferucarbotran-enhanced MR imaging with accumulation-phase FS-T1WI is superior to gadolinium-enhanced MR imaging in characterization of T1W hyperintense nodule within cirrhotic liver and T1W hyperintense nodule within cirrhotic liver depicting hyperintense on ferucarbotran-enhanced accumulation-phase FS-T1WI should be investigated aggressively. In summary, it is hard to determine which types of hepatic nodules are precancerous in “multistep” carcinogenesis for patient with chronic liver disease. Through the specific property of ferucarbotran for liver, the ferucarbotran-enhanced MR offered additional information in characterization and detection of HCC. We successfully used the ferucarbotran-enhanced accumulation phase FS-T1WI to improve detection of HCC and characterization of T1W hyperintense nodule within patients with liver cirrhosis.
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Shao, Ju-Mei, and 邵如梅. "Next-generation Sequencing (NGS)-based Genetic Testing for Tuberous Sclerosis Complex (TSC) - Highlighting on Focal Lesion Sequencing & Clinical Research Database." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/22z983.
Full textAbstract:
碩士國立臺灣大學
分子醫學研究所
104
Tuberous sclerosis complex (TSC) is an autosomal dominant disease due to causative variants at either TSC1 or TSC2. The disease-causating mutations are highly variable and 10–20% of TSC individuals have no causative variants identified after thorough conventional molecular diagnostic assessment. In this study, 110 definite TSC probands were studied using next-generation sequencing (NGS) to search for pathogenic variants at TSC1 and TSC2 genes. “Pathogenic” or “likely pathogenic” variants were identified in 96 (87%) probands; however, 14 (13%) probands could not be assigned causative variants. Among the 96 identified causative variants, 58 (60%) were single nucleotide substitutions, 28 (29%) were small indels, and 10 (10%) were large deletions/duplications. Fourteen (15%) probands were found to have variants at TSC1 and 82 (85%) were found to have variants at TSC2. Seven individuals were mosaic regarding to their causative variants, including 5 probands and parents of other two non-mosaic probands. A splicing site variant “TSC2, c.138+5G>T” was identified in one TSC family co-segregated in 2 affected family members. With the intent to investigate the genetic etiology in those TSC patients without identifiable causative variants at TSC1 or TSC2, we conducted sequencing using focal lesion DNA. A total of 10 focal lesions obtained from 3 no-mutation-identified probands and 2 probands with one germline mutation (positive control) were studied. One pathogenic mutation at TSC2 with 0.6% of allele percentage was detected in the focal lesion DNA of one no-mutation-identified proband. This variant was considered as the second-hit mutation and indicated that the germline mutation in this patient is located in TSC2 gene as well. However, no potential second-hit mutation was identified in the positive control samples. These findings concluded and suggested that there were several possible reasons for no-mutation-identified status in TSC patients: 1) mosaicism with very low allele percentage for variants at TSC1 or TSC2; 2) variants in introns that affect splicing, or in promoter and enhancer regions of TSC1 and TSC2; 3) variants detection failure due to technical issues; 4) variants at a yet-unknown third TSC gene. Furthermore, to manage the clinical research data collected from TSC Genetic Research, a user-friendly online clinical research database - Clinical Study Information System (CSIS) was established. The study-specified data entry forms were designed for TSC Genetic Research and the system was under security protection by personal ID and password for researchers who were delegated to this study. All the available data including the clinical information from subjects and genetic test results were entered and managed by our study team accordingly.
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Labelle-Chiasson, Vincent. "Évaluation de la cognition sociale : étude du raisonnement moral chez l’enfant neurotypique et avec lésion cérébrale focale." Thèse, 2017. http://hdl.handle.net/1866/20617.
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"Advances in needle-related percutaneous intervention of focal liver lesions." Thesis, 2006. http://library.cuhk.edu.hk/record=b6074215.
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Focal liver lesions are commonly encountered in clinical practice. To be able to differentiate potentially life-threatening lesions from clinically insignificant lesions, and to be able to treat them effectively are the two basic problems of a clinician who comes across such lesions. Percutaneous intervention of the liver with a needle enables a clinician to solve the above two problems in a minimally invasive manner. To date, there is a diversity of needle-related percutaneous interventional procedures that are applicable to the clinical management of patients with liver lesions, such as biopsy of focal lesions, drainage of abscesses, and ablation of tumors. Despite a reasonable safety and efficacy associated with these procedures, there are always grounds of further improvement in techniques and technology of needle-related percutaneous procedures to achieve an even better outcome. It was hypothesized that the application of needle-related interventional radiology to clinical management of focal liver lesions could be facilitated and extended with advancement and refinement in needle-related techniques and technology. This thesis was based on a series of nine studies that aimed to explore the potential of needle-related percutaneous interventions in the clinical management of focal liver lesions and to study the effect of the introduction of innovations in needle-related techniques and technology on such clinical applications. It was concluded that the hypothesis was confirmed.Yu Chun Ho.
"April 2006."
Adviser: Anil Ahuja.
Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5176.
Thesis (M.D.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references (p. 219-235).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
School code: 1307.
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"The effectiveness of color power angiography in differentiation of focal hepatic lesions." 1998. http://library.cuhk.edu.hk/record=b5889773.
Full textAbstract:
by Young Lee Kei, Ricky.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 205-207).
Abstract also in Chinese.
Acknowledgements --- p.i
Statement of Originality --- p.ii
Abstract --- p.iii
Chapter Chapter 1 --- Introduction
Chapter 1.1 --- Anatomy of liver --- p.1
Chapter 1.2 --- Anatomical Implications --- p.16
Chapter Chapter 2 --- Background
Chapter 2.1 --- Common focal hepatic lesions --- p.21
Chapter 2.2 --- Imaging techniques --- p.28
Chapter 2.3 --- Characterization by sonography --- p.34
Chapter 2.4 --- Color Power Angiography --- p.38
Chapter Chapter 3 --- Hypothesis & Aims
Chapter 3.1 --- Hypothesis --- p.44
Chapter 3.2 --- Aims & Objectives --- p.45
Chapter Chapter 4 --- Material and Methods
Chapter 4.1 --- Materials --- p.47
Chapter 4.2 --- Mode of confirmation --- p.52
Chapter 4.3 --- Final number of subjects recruited --- p.54
Chapter 4.4 --- Method for obtaining CD and CPA image --- p.58
Chapter 4.5 --- Method for image analysis --- p.61
Chapter 4.6 --- Statistical analysis --- p.68
Chapter Chapter 5 --- Results
Chapter 5.1 --- Qualitative CD and CPA images assessment --- p.70
Chapter 5.2 --- Interobserver qualitative analysis --- p.78
Chapter 5.3 --- Spectral analysis --- p.84
Chapter 5.4 --- Semi-quantitative signal parameters --- p.87
Chapter 5.5 --- Dominance of quantified signals --- p.91
Chapter 5.6 --- Distribution of signals in various lesions (graphical presentation) --- p.97
Chapter 5.7 --- Penetrating vessel --- p.103
Chapter 5.8 --- Relationship between size of lesion and quantified signal parameters --- p.104
Chapter Chapter 6 --- Discussion
Chapter 6.1 --- Study Review --- p.109
Chapter 6.2 --- Methods of quantitation --- p.110
Chapter 6.3 --- Value of quantitation --- p.111
Chapter 6.4 --- Instrumentation --- p.112
Chapter 6.5 --- Subjects --- p.114
Chapter 6.6 --- Image analysis --- p.115
Chapter 6.7 --- Results --- p.117
Chapter 6.8 --- Relationship between size and amount of signals --- p.131
Chapter 6.9 --- Differentiation of focal hepatic lesions --- p.132
Chapter 6.10 --- Origin of CPA signals in small hyperechoic lesions --- p.144
Chapter 6.11 --- Limitations of CPA in focal hepatic lesion imaging --- p.146
Chapter 6.12 --- Comparison with similar studies --- p.151
Chapter 6.13 --- Validation of quantitation results --- p.158
Chapter Chapter 7 --- Conclusions --- p.159
References --- p.162
Legends --- p.176
Tables --- p.186
Glossary of abbreviations --- p.193
Selected publications relevant to thesis --- p.197
Appendix --- p.198
Bibliography --- p.205
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Lin, Wen-Pei, and 林文旆. "Evaluation of liver with diffusion weighted magnetic resonance imaging and characterization of focal hepatic lesions." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/bzy33b.
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碩士元培科技大學
影像醫學研究所
96
Abstract Background and purpose: Magnetic resonance diffusion-weighted image (DWI) is a useful technique which detects water diffusivity by applying diffusion gradient in three-orthogonal directions. The purpose of this study is to investigate the changes of water diffusivity in liver tissue with diseases, and further differentiate disease types by measured apparent diffusion coefficient (ADC). Material and methods: In this study, we enrolled 55 patients with hepatoma, hemangioma, hepatic cyst, cirrhosis and metastasis. The diffusion-weighted pulse sequence was conducted on those patients at a 1.5T MR scanner (GE, Signa HDx) using two diffusion-weighting factors, b=0 and 500 s/mm2, and ADC value was calculated after data acquisition. Results: ADC value is (1.31±0.28) x 10-3 mm2/sec in hepatoma tissue, (2.82±0.88) x 10-3 mm2/sec in hemangioma, (3.70±0.51) x 10-3 mm2/sec in hepatic cyst, (1.30±0.40) x 10-3 mm2/sec in hepatic cirrhosis, and is (0.99±0.04) x 10-3 mm2/sec in metastasis. Discussion and conclusions: We evaluated 55 patients with hepatic diseases, and our study shows consistent results with previous report. Our study demonstrated DWI has high differentiating rate, high contrast and SNR, suggesting that DWI is capable of studying hepatic tissue, and can be a helpful technique for differentiating hepatic diseases. Keywords: Magnetic resonance imaging, Brownian motion, Differentiating rate, contrast, SNR
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Chiu, Fang-Ying, and 邱芳瑩. "Effect of Intravenous Gadolinium-DTPA on Diffusion-Weighted MR Images for Evaluation of Focal Hepatic Lesions." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/53573384122124259376.
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碩士高雄醫學大學
醫學研究所碩士班
92
Diffusion-weighted imaging (DWI) is usually done before administration of intravenous magnetic resonance（MR） contrast agents. Repetition of DWI is occasionally necessary after contrast administration, but the effects of contrast material on DWI and apparent diffusion coefficient (ADC) values have not yet been fully examined. The purpose of this research is to assess whether administration of contrast material of gadopentetate dimeglumine（Gd-DTPA） significantly affects DWI and ADC values. We examined DWI by 3.0 T scanner in 20 consecutive patients (mean age, 68 years; range, 33 to 86 years) who were evaluated with a liver protocol at our hospital. All patients were scanned for the hepatic lesion. We obtained DWI using single-shot echo-planar imaging with a b value of 500s/mm2. Patients were injected with 0.1 mmol gadopentetate dimeglumine per 1 kg body weight. We examined the signal-to-noise ratio (SNR) of the normal liver and the hepatic lesions and evaluated the contrast-to-noise ratio (CNR) of each lesion. In addition, we compared the ADC values calculated from the DWI images before and after administration of contrast. The statistical significance of differences between pre-contrast and post-contrast administration was determined by use of a paired two-tailed t test. The signal-to-noise and contrast-to-noise ratios of the DWI were not significantly different before and after administration of the contrast agent ( p ＞ 0.05 ). The ADC values were decreased after administration of the contrast agent for different hepatic lesions ( p = 0.097). The insignificant difference of the signal-to-noise and contrast-to-noise ratios of DW MR images between pre- and post-contrast administration indicates the feasibility of post-contrast enhanced DWIs.
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Namkung, Sook [Verfasser]. "Superparamagnetic iron oxide (SPIO)-enhanced liver MR imaging with ferucarbotran : efficacy for characterization of focal liver lesions with T2-weighted FSE and T2*-weighted GRE and early dynamic T1-weighted GRE sequences / vorgelegt von Sook Namkung." 2006. http://d-nb.info/98196723X/34.
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Yan, Li [Verfasser]. "Changes in pre- and postsynaptic function during the phase of enhanced long-term synaptic plasticity at the border of focal lesions in rat visual cortex = Änderungen der prä- und postsynaptischen Funktion in der Phase verstärkter synaptischer Plastizität im Randbereich von fokalen Läsionen im visuellen Kortex der Ratte / Li Yan." 2007. http://d-nb.info/989021572/34.
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