Introduktion: Dagens strålskyddsprinciper om gonadskydd är i grunden baserade på ALARA principen utöver de olika lagar och författningar som implementeras med tidens gång. Att uppnå diagnostisk kvalitet på bilden utan att ta bort vital information är därför av intresse för röntgensjuksköterskan. Felaktig placering av gonadskyddet kan leda till ökad stråldos samt informationsbortfall, eventuellt även omtag av bilden. Ökande stråldos ger högre risk för genetiska skador på arvsmaterialet samt risken att utveckla cancer. Syfte: Att undersöka förekomsten, mängden felplacerade gonadskydd samt effekten av felplacerade gonadskydd. Metod: En allmän litteraturöversikt baserat på kvantitativa artiklar genomfördes där elvavetenskapliga artiklar kvalitetsgranskades. Sökningar gjordes i databaserna PubMed, CINAHL och Google Scholar. Resultat: Resultat visar att felplacerade gonadskydd leder till omtag av röntgenbilder och patienter utsätts för mer stråldos. Det ökar risken för strålskador. Detta går emot ALARA-principen som ska tillämpas av röntgensjuksköterskor. Slutsats: Mycket av nyligt utkommen forskning pekar på att gonadskydd används ofta felaktigt och skapar då förutsättningar för ökad stråldos för patienten. Huruvida gonadskydd bör avskaffas är något som kräver mer forskning för att avgöra

L'évolution des techniques d'acquisition des imageries médicales et leur importance de plus en plus grande dans la prise en charge du patient (diagnostic, préparation d'intervention, suivi, etc.), font émerger de nouveaux besoins autour du traitement informatique des images. La reconnaissance du type de lésions hépatiques est un grand enjeu, notamment car le cancer du foie, létal et très répandu, est souvent diagnostiqué trop tard pour sauver le patient. C'est dans ce cadre qu'est né le projet de recherche de ce manuscrit, fruit d'une collaboration entre la société IMAIOS et le Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier (LIRMM).Cette thèse présente un système complet et automatique permettant, à partir d'images de lésions au format médical DICOM, d'extraire des descripteurs visuels de divers nodules hépatiques puis de les différencier à l'aide de ces derniers. Les contributions décrites s'articulent autour de divers axes : normalisation des niveaux de gris des images de lésions par rapport au foie sain, proposition, analyse et tests de descripteurs visuels (s'appuyant notamment sur les informations temporelles ou de densité des tissus), caractérisations diverses des différents types de lésions grâce à ces descripteurs et à un algorithme de classification. Les données sur lesquelles ces travaux ont été effectués sont des examens scanner multiphasiques. / Medical imaging acquisition has taken benefits from recent advances and is becoming more and more important in the patient care process. New needs raise, which are related to image processing. Hepatic lesion recognition is a hot topic, especially because liver cancer is wide-spread and leads to death, most of the time because of the diagnosis which is made too late. In this context is born this manuscrit research project, a collaboration between IMAIOS company and the Laboratory of Informatics, Robotics and Micro-electronics ofMontpellier (LIRMM).This thesis presents a complete and automated system that extracts visual features from lesion images in the medical format DICOM, then differenciate them on these features.The various described contributions are: intensity normalization using healthy liver values, analysis and experimentations around new visual features, which use temporal information or tissue density, different kind of caracterisation of the lesions. This work has been done on multi-phase Computed Tomography acquisitions.

O objetivo deste estudo foi uma avaliação tridimensional as mudanças nas dimensões transversais, verticais e anteroposterior das estruturas dentais e dentoalveolares em pacientes com deficiência maxilar transversal (DMT) submetidas à expansão rápida de maxila assistida cirurgicamente (ERMAC) através do uso de tomografias computadorizadas do feixe cônico (TCFC). Trinta e oito pacientes com DMT foram submetidos à ERMAC sob anestesia geral, as TCFC foram realizadas no pré-operatório (T1), após a expansão desejada (T2) e seis meses após a expansão (T3). Quarenta e sete marcações tridimensionais foram realizadas como pontos de referência e marcadas em cada tempo. As distâncias e ângulos foram medidas a fim de se avaliar as alterações ocorridas após a expansão. Os resultados demonstraram diferenças estatísticas significantes na dimensão transversal através do teste ANOVA ao nível da câmara pulpar (P&le;0.001) em T2-T1 e T3-T1; e ao nível do ápice dental com diferença estatisticamente significante (P<0.005) em T2-T1 e T3-T1 e ao nível do processo dentoalveolar com diferença estatísticamente significante de (P<0.05) em T2-T1e T3-T1. A inclinação dentária apresentou diferença estatísticamente significante somente no incisivo central esquerdo (P< 0.05) em T3-T1. As dimensões vertical e anteroposterior não apresentaram diferenças estatísticamente significante. As maiores mudanças ocorreram na dimensão transversal na maioria das estruturas avaliadas, alterações verticais e anteroposteriores não foram encontradas. O índice de recidiva após seis meses da realização da ERMAC é baixa e podemos considerar como um tratamento estável para pacientes com DMT. / The objective of this study was evaluate three-dimensional changes on transversal, vertical and anteroposterior dimensions of dental and dentoalveolar structures in patients with maxillary transverse deficiency (MTD) submitted to surgically assisted rapid maxillary expansion (SARME) using by CBCT. Thirty eight subjects with MTD was submitted to SARME under general anesthesia, CBCTs was taken preoperative (T1), after desired expansion (T2) and six months after expansion (T3). Fourth seven three-dimensional landmarks were determinate as reference points and marked at each time. The distances and angles were measured regarding the changes occurred after expansion.The results showed statistical significance difference in transverse dimension by ANOVA test at level of pulp chamber (P&le;0.001) at T2-T1 and T3-T1; at level of dental apex had statistical difference (P<0.005) at T2-T1 and T3-T1, at level of dentoalveolar processes had statistical difference (P<0.05) at T2-T1 and T3-T1. Dental tipping showed statistical difference only left central incisors (P< 0.05) at T3-T1 Vertical and anteroposterior dimensions do not have statistical difference. The greater changes occurred in transversal dimensions and most of structures evaluated, no vertical and anteroposterior changes were found. The index relapse after six months is low and SARME can be consider stable to treatment of MTD.

Der ehemalige Salzbergbau im Raum Staßfurt führt seit dem 19. Jahrhundert zu Subrosion und teils bruchhaften Deformationen und damit verbundenen Senkungen und Vernässungen im Stadtgebiet. Im Rahmen eines Forschungsverbundvorhabens unter Federführung der BGR sollen in dieser Arbeit die grundlegenden strömungsdynamischen Prozesse im Salinar und Deckgebirge der betroffenen geologischen Formationen aufgeklärt werden. An Bohrkernen aus den entsprechenden Bereichen werden Durchflussexperimente durchgeführt und die Fluiddynamik im Inneren der Proben mittels Positronen-Emissions-Tomographie dreidimensional dargestellt. In Kooperation mit der Bundesanstalt für Materialforschung- und prüfung Berlin und dem Geologischen Institut der Johannes-Gutenberg Universität Mainz werden diese PET-Messungen der Fluiddynamik mit hochauflösenden computertomographischen Messungen der internen Struktur der Proben in Übereinstimmung gebracht. Die beobachteten Fließmuster sollen mittels einer Lattice-Boltzmann-Simulation nachvollzogen und dadurch das grundlegende Verständnis der Strömungsdynamik in diesen Gesteinen erweitert werden. Langfristig soll dies zu einer Verbesserung des Verständnisses der Grundwasserdynamik auf regionaler Ebene führen.

Made available in DSpace on 2016-08-03T16:31:16Z (GMT). No. of bitstreams: 1 1 CAPA E FOLHA DE ROSTO.pdf: 8768 bytes, checksum: 995763bdcb7f03d5aae11a4cf0972b49 (MD5) Previous issue date: 2011-03-29 / The present study aimed to assess the mesiodistal angle, upper first and second molars distalization and the space for upper third molars in patients treated with Forsus® associated to fixed appliance. Sample consisted of 44 lateral cephalograms (22 right side, and 22 left side) obtained from 11 Cone-Bean Computed Tomography (CBCT) of 11 patients, in two phases: before (T1) and after (T2) the Forsus®. appliance. After obtaining the lateral cephalograms, points, lines and planes were marked, to measure the variables of interest. For evaluation of the space for upper third molars, it was used a reference line (PTVR), from point PTV, perpendicular to Frankfurt plane, measuring the distance until the distal face of first and second upper molars. To evaluate the long axis of upper first and second molars, it was measured the angle formed between such teeth and the palatal plane. The software used was Radiocef Studio 2 and for statistical analysis it was used paired "t" test. Results showed there was distalization and distal tipping of upper first and second molars, with a greater magnitude in first molars. Alterations in right and left sides were similar. It was also noticed that there was a reduction in the probability of eruption of third molars. / A presente pesquisa avaliou a angulação mésio-distal e a distalização dos primeiros e dos segundos molares superiores permanentes em pacientes tratados com o aparelho Forsus® em conjunto com o aparelho ortodôntico fixo. A amostra foi composta por 44 teleradiografias, (22 do lado direito e 22 do lado esquerdo), obtidas por meio de 11 tomografias computadorizadas, de 11 pacientes, realizadas em dois tempos: antes (T1) e após (T2) a instalação do aparelho Forsus®, tratados na clínica de Pós-Graduação em Odontologia, área de Ortodontia, da Universidade Metodista de São Paulo. Após a obtenção dos cortes tipo telerradiografia, foi realizada a marcação dos pontos, linhas e planos, e realizada a mensuração das variáveis de interesse. Para avaliação do espaço para os terceiros molares superiores, utilizou-se uma linha referencial (linha PTVR), demarcada a partir do ponto PTV, perpendicular ao plano de Frankfurt. O espaço avaliado compreendeu entre a Linha PTVR, até a face distal do primeiro molar e do segundo superior permanente. Para avaliar o longo eixo dos primeiros e segundos molares superiores, mensurou-se o ângulo formado entre esses dentes e o plano palatino. Para auxílio das mensurações, foi utilizado o software Radiocef Studio 2. Na análise estatística usou-se o teste t pareado. Concluiu-se que houve distalização e aumento da angulação distal dos primeiros e segundos molares superiores, sendo que nos segundos molares a distalização e angulação distal da coroa ocorreram em menor quantidade; os efeitos do lado direito e esquerdo foram semelhantes; pode-se também constatar que ocorreu uma redução na probabilidade de erupção dos terceiros molares superiores.

O objetivo deste estudo foi uma avaliação tridimensional as mudanças nas dimensões transversais, verticais e anteroposterior das estruturas dentais e dentoalveolares em pacientes com deficiência maxilar transversal (DMT) submetidas à expansão rápida de maxila assistida cirurgicamente (ERMAC) através do uso de tomografias computadorizadas do feixe cônico (TCFC). Trinta e oito pacientes com DMT foram submetidos à ERMAC sob anestesia geral, as TCFC foram realizadas no pré-operatório (T1), após a expansão desejada (T2) e seis meses após a expansão (T3). Quarenta e sete marcações tridimensionais foram realizadas como pontos de referência e marcadas em cada tempo. As distâncias e ângulos foram medidas a fim de se avaliar as alterações ocorridas após a expansão. Os resultados demonstraram diferenças estatísticas significantes na dimensão transversal através do teste ANOVA ao nível da câmara pulpar (P&le;0.001) em T2-T1 e T3-T1; e ao nível do ápice dental com diferença estatisticamente significante (P<0.005) em T2-T1 e T3-T1 e ao nível do processo dentoalveolar com diferença estatísticamente significante de (P<0.05) em T2-T1e T3-T1. A inclinação dentária apresentou diferença estatísticamente significante somente no incisivo central esquerdo (P< 0.05) em T3-T1. As dimensões vertical e anteroposterior não apresentaram diferenças estatísticamente significante. As maiores mudanças ocorreram na dimensão transversal na maioria das estruturas avaliadas, alterações verticais e anteroposteriores não foram encontradas. O índice de recidiva após seis meses da realização da ERMAC é baixa e podemos considerar como um tratamento estável para pacientes com DMT. / The objective of this study was evaluate three-dimensional changes on transversal, vertical and anteroposterior dimensions of dental and dentoalveolar structures in patients with maxillary transverse deficiency (MTD) submitted to surgically assisted rapid maxillary expansion (SARME) using by CBCT. Thirty eight subjects with MTD was submitted to SARME under general anesthesia, CBCTs was taken preoperative (T1), after desired expansion (T2) and six months after expansion (T3). Fourth seven three-dimensional landmarks were determinate as reference points and marked at each time. The distances and angles were measured regarding the changes occurred after expansion.The results showed statistical significance difference in transverse dimension by ANOVA test at level of pulp chamber (P&le;0.001) at T2-T1 and T3-T1; at level of dental apex had statistical difference (P<0.005) at T2-T1 and T3-T1, at level of dentoalveolar processes had statistical difference (P<0.05) at T2-T1 and T3-T1. Dental tipping showed statistical difference only left central incisors (P< 0.05) at T3-T1 Vertical and anteroposterior dimensions do not have statistical difference. The greater changes occurred in transversal dimensions and most of structures evaluated, no vertical and anteroposterior changes were found. The index relapse after six months is low and SARME can be consider stable to treatment of MTD.

Made available in DSpace on 2016-08-17T14:53:18Z (GMT). No. of bitstreams: 1 dissertacao Alex Martins Santos.pdf: 5806595 bytes, checksum: 431584590b26aa21a56d684cd9c7f282 (MD5) Previous issue date: 2011-08-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Lung cancer stands out by pointing the highest incidence and higher mortality rate of all other types of cancer. It has one of the lower survival rates of after diagnosis, which is mainly due to late detection and therefore delayed treatment. Computer-aided detection systems (CAD) are developed to assist the specialist in the search and identification of nodules and changes in CT. These systems respectively aim to automate the identification and classification of these structures. This work aims to study and develop a methodology for automatic detection of small lung nodules (bigger than 2 mm and smaller than 10 mm in diameter). The proposed methodology is based on techniques of image processing and pattern recognition. Similar applications use widely some of these techniques. The proposed methodology also uses other techniques from different areas and applications, such as measures of the Tsallis and Shannon entropy used in this study to describe suspected structures. These measures are respectively provided from statistical mechanics and information theory, however lately they have been successfully applied in image processing. It was also used the Gaussian mixture model (GMM) and the Hessian matrix calculation to separate the internal structures of the remaining lung parenchyma. Promising results were found in tests with 140 exams divided in of 80% for training and 20% for testing. It was achieved a 79% of sensitivity rate and a total of 1.17 false positives per slice. / Dentre os outros tipos de câncer, o câncer de pulmão se destaca por apresentar a maior incidência e a maior taxa de mortalidade de todos, além de uma das menores taxas de sobrevida após o diagnóstico (cinco anos em média), fato este decorrido principalmente pela detecção e, conseqüentemente, tratamento tardio. Para auxiliar o especialista na busca e identificação de nódulos e alterações em imagens tomográficas são desenvolvidos sistemas de detecção auxiliados por computador (CAD) que visam automatizar os trabalhos de identificação e classificação de dessas estruturas. O presente trabalho tem por objetivo o estudo e desenvolvimento de uma metodologia para detecção automática de nódulos pulmonares pequenos (maiores que dois milímetros e menores que 10 milímetros de diâmetro). A metodologia proposta se baseia em técnicas de processamento de imagens e reconhecimento de padrões. Algumas dessas técnicas são amplamente utilizadas em aplicações similares, já outras técnicas utilizadas provêm de outras áreas e aplicações, como é o caso das medidas de entropia de Tsallis e Shannon, utilizados neste trabalho para descrever estruturas suspeitas. Estas medidas provém respectivamente da mecânica estatística e da Teoria da Informação, porém ultimamente tem sido aplicadas com sucesso no processamento de imagens. Também foi empregado o Modelo de Misturas Gaussianas (GMM) e o cálculo da matriz Hessiana para separar as estruturas internas do pulmão do restante do parênquima. Resultados promissores foram encontrados, em teste com 140 exames divididos em 80% para treino e 20% para testes, alcançou-se uma sensibilidade de 79% e um total de 1,17 falsos positivos por fatia.

Abstract In the Nordic countries, event-free survival (EFS) exceeds 80% in certain groups of children treated for acute lymphoblastic leukaemia (ALL). With the improved cure rates, however, there are more children suffering from neurological late effects, especially due to therapy directed at the central nervous system (CNS). The aim of this study is to examine the changes taking place in the nervous system after leukemia treatment and to evaluate the role of treatment in these changes in patients and in an animal model. Twenty-seven ALL survivors and healthy controls were examined by means of motor evoked potentials (MEPs). ALL survivors were also examined clinically. The children with ALL continued to show decreased motor nerve conduction in the peripheral nerves, but not within the CNS, five years after the cessation of treatment. Clinical neurological findings were obtained in 33% of the cases. The MEP results indicated reversibility of the motor injury due to CNS effects. Nineteen patients underwent perfusion magnetic resonance imaging (MRI) at the cessation of treatment or 4-8 years after the treatment. Seventeen of them also underwent single-photon emission computed tomography (SPECT). The studies showed small perfusion defects in SPECT, which were not visible by perfusion MRI. Methotrexate (Mtx) neurotoxicity was studied in a swine model using functional MRI, brain perfusion SPECT, iodine-123 labelled 2β-carbomethoxy-3β-(4-iodophenyl) tropane ([123I]β-CIT) SPECT and whole-hemisphere autoradiography with [125I]β-CIT in ten Mtx-treated animals and five control animals. Mtx-related changes in the brain could be detected as reduced or negative blood-oxygen-level-dependent (BOLD) responses to somatosensory activation in BOLD contrast MRI, which indicates changes in flow metabolism coupling. Perfusion defects in brain SPECT were seen in the Mtx group and the control group, which suggests that the perfusion defects seen in brain SPECT are probably multifactorial. The change in dopamine transporter (DAT) density in the Mtx group was not different from that in the controls. The abnormalities in nerve conduction after treatment in survivors of ALL were partly reversible years after the treatment. The patients had perfusion defects in SPECT imaging which were not seen in perfusion MRI. The clinical significance of these defects remains obscure. The animal model suggested perfusion defects to be multifactorial.

The aim of the master’s thesis, is to get acquainted with the dynamic focusing in conventional ultrasound systems, to modify this method for ultrasound computer tomography and to realize and interpret this modification on simulated and real data in a transparent graphic interface. The modification of the dynamic focusing was executed for the 3D ultrasound computer tomograph developed in Karlsruhe. Simulated data, that are necessary for focusing, were generated by existing program, which was adjusted. The new created program of the dynamic focusing was tested and evaluated with those simulated and real data.

Antalet datortomografiundersökningar (DT) ökar i Sverige och hela världen. En nackdel med denna undersökning är höga stråldoser som kan orsaka stokastiska skador (cancer) på patienter. Mest strålkänsliga patienter är barn. De har snabbare celldelning och längre livstid kvar vilket innebär att cancer har större möjlighet att utvecklas i framtiden. Syfte: Syfte med denna studie är att belysa hälsorisker som kan förekomma vid joniserande strålning inom DT med fokus på barn samt unga vuxna. Metod: En litteraturöversikt gjordes där artiklarna valdes från två databaser PubMed och CINAHL. 10 artiklar kvalitetsgranskades och resultaten av de utvalda artiklarna analyserades. Resultat:  Resultaten visade att DT-undersökning som genomförs under barndomen kan leda till ökad risk för malignitet och deterministiska skador. Det finns ett direkt samband mellan mängden av stråldos, ålder och kön vid exponering av joniserande strålning av DT och risken att drabbas av cancer. Ju högre dos och desto yngre patienten är, samt hos flickor överlag, finns större risk att drabbas av cancersjukdom. Slutsatser: På grund av hälsorisker som förekommer efter exponering med joniserande strålning krävs ett stort ansvar både hos radiologer och röntgensjuksköterskor, för att minimera skadorna hos barn. Därför är det även av stor vikt att alla undersökningar som utförs inom DT är berättigade och optimerade för att nyttan av att utföra undersökningen ska bli större än skadan. / The number of computed tomography (CT) examinations is increasing in Sweden and worldwide. A disadvantage of this method is high radiation doses that can cause stochastic effects (cancer) on patients. The most radiation-sensitive patients are children. They have faster cell division and longer life, which means that cancer has a greater chance of developing in the future. Aim: The aim of this study is to elucidate health risks that can occur in ionizing radiation in CT with focus on children and young adults. Method: A literature review was conducted where the articles were selected from the two databases PubMed and CINAHL. Ten articles were quality checked and the results of the selected articles were analyzed.Results: The results showed that CT examination conducted during childhood could lead to an increased risk of malignancy and deterministic injuries. There is a direct correlation between the amount of radiation dose, age and sex, when exposed to ionizing radiation from CT and the risk of cancer. The higher the dose and the younger the patient, and in girls overall, there is a greater risk of suffering from cancer. Conclusions: Due to health risks that occur after exposure to ionizing radiation, a great responsibility is required of both radiologists and X-ray nurses, to minimize the damage in children. Therefore, it is also of great importance that all investigations carried out within CT are justified and optimized so that the benefit of carrying out the investigation should be greater than the damage.