Dissertations / Theses on the topic 'Head Radiography'

Pathologische Veränderungen der Wirbelsäule können zur Verkleinerung der Foramina intervertebralia der Halswirbelsäule sowie zur Verkürzung der Abstände zwischen den Dornfortsätzen der Brustwirbelsäule führen. Eine Veränderung der Kopf-Hals-Haltung kann ebenfalls die Dimension der Foramina intervertebralia sowie die Abstände zwischen den Dornfortsätzen beeinflussen. Die Bestimmung des Einflusses der Kopf-Hals-Haltung auf die genannten Parameter bei der radiologischen Darstellung der Wirbelsäule war deshalb das Ziel der vorliegenden Arbeit. In drei unterschiedlichen Kopf-Hals-Haltungen wurde die Halswirbelsäule von 25 klinisch unauffälligen Pferden im laterolateralen Strahlengang dargestellt. Laterolaterale Röntgenaufnahmen der Brustwirbelsäule von 23 Pferden ohne klinische Anzeichen einer Erkrankung der Wirbelsäule wurden ebenfalls in drei verschiedenen Kopf-Hals-Haltungen angefertigt. Die Auswertung dieser Aufnahmen erfolgte mit Hilfe von neu entwickelten Messmethoden, die eine hohe Reproduzierbarkeit aufwiesen. Auf den Aufnahmen der Halswirbelsäule wurde die Länge der Wirbelkörper und die Dimension der Foramina intervertebralia bestimmt. Zusätzlich wurden die Winkel zwischen angrenzenden Halswirbeln ermittelt. Der Abstand zwischen benachbarten Dornfortsätzen sowie die Breite der Dornfortsätze wurden für die Auswertung der Aufnahmen der Brustwirbelsäule gemessen. Für eine exaktere Auswertung der Aufnahmen der Brustwirbelsäule wurde ein spezieller Bildfilter entwickelt, der durch eine bessere Detailerkennbarkeit zu einer genaueren Messung der Streckung führte. Sowohl für die Breite der Dornfortsätze als auch für die Länge der Wirbelkörper der Halswirbel konnten keine signifikanten Unterschiede zwischen den Röntgenaufnahmen in den verschiedenen Kopf-Hals-Haltungen gefunden werden. Beide Strecken dienten zur Überprüfung des Versuchsaufbaus, um andere Ursachen für eine unterschiedliche Größe der Messstrecken auszuschließen. Die Foramina intervertebralia waren bei tiefer Kopf-Hals-Haltung signifikant größer als bei den anderen beiden Kopf-Hals-Haltungen (p &lt; 0,05). Zwischen hoher und physiologischer Kopf-Hals-Haltung stellten sich nur die Foramina intervertebralia zwischen sechstem und siebten Halswirbel unterschiedlich groß dar (p &lt; 0,05). Die Abstände zwischen angrenzenden Brustwirbeln waren vom achten bis zum vierzehnten Dornfortsatz in tiefer Kopf-Hals-Haltung größer als in den beiden anderen Kopf-Hals-Haltungen (p &lt; 0,05). Diese Abstände nahmen insgesamt von kranial nach kaudal ab (p &lt; 0,05) ab. Der zwölfte Dornfortsatz diente dabei zur Identifizierung der anderen, da er sich signifikant von den schmaleren kranialen und den breiteren kaudalen Dornfortsätzen unterschied (p &lt; 0,01). Die Kopf-Hals-Haltung während der radiologischen Untersuchung beeinflusst sowohl die Dimension der Foramina intervertebralia als auch den Abstand zwischen den Dornfortsätzen. Deshalb sollte diese bei der Auswertung radiologischer Aufnahmen immer berücksichtigt werden. Die Foramina intervertebralia stellten sich bei tiefer Kopf-Hals-Haltung am größten dar und können somit in dieser am besten beurteilt werden, jedoch kommt es zu einer Veränderung der Anordnung der Wirbel, so dass diese nur noch eingeschränkt beurteilt werden können. Eine tiefe Kopf-Hals-Haltung führt zur Vergrößerung der Abstände zwischen den Dornfortsätzen und kann somit die Beurteilung von Röntgenaufnahmen der Brustwirbelsäule, gerade im Rahmen einer Kaufuntersuchung, beeinflussen. Die Kopf-Hals-Haltung bei der Anfertigung von Röntgenaufnahmen der Wirbelsäule sollte standardisiert werden, um durch verbesserte Vergleichbarkeit Manipulationen und Fehlinterpretationen einzuschränken<br>Pathological changes of the spine can lead to reduction of the intervertebral foramina dimensions in the cervical spine and to shortening of the distances between the spinous processes in the thoracic spine. However, alteration of the head and neck position influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Determining the influence of the head and neck position on these parameters during radiological examination of the equine spine was the aim of this study. In three different head and neck positions lateral-lateral views of the cervical spine in 25 clinically sound horses were radiographically obtained. Lateral-lateral radiographs of the thoracic spine from 23 horses lacking clinical signs of spine diseases were taken in three different head and neck positions. Evaluation of the radiographs was carried out with newly developed measurement techniques providing high reproducibility. On the radiographs of the cervical spine the length of the vertebral bodies and the dimension of the intervertebral foramina were measured. Additionally, the angles between adjacent cervical vertebrae were determined. The distances between adjacent spinous processes and the width of the spinous processes were measured for evaluating the radiographs of the thoracic spines. For a more accurate evaluation of the thoracic spine radiographs a purpose-built image filter was developed, which provided more accurate measurement of the distances through better detail recognition. No significant differences were found for the width of the spinous processes of the thoracic vertebrae and the length of vertebral bodies of the cervical vertebrae between the radiographs taken in the three different head and neck positions. Both these distances were used to verify the experimental set-up to rule out other causes for differences in the measured distances. The intervertebral foramina were significantly wider in the low head and neck position than in the other two head and neck positions (p &lt; 0.05). Between the high and the free head and neck position only the intervertebral foramina of the sixth and seventh cervical vertebrae showed different dimensions (p&lt; 0.05). The distances between the adjacent thoracic vertebrae from the eighth to the fourteenth spinous processes were wider in the low head and neck position compared to the other two head and neck positions (p &lt; 0.05). Altogether, these distances decreased from cranial to caudal (p &lt; 0.05). The twelfth spinous process served for numerical identification of the other spinous processes due to its significant difference in width to the narrower cranial and broader caudal spinous processes (p &lt; 0.05). The head and neck position during radiographic examination influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Therefore, it should always be considered when evaluating radiographs. In the low head and neck position the intervertebral foramina turned out to be the widest and could be best assessed. However, this resulted in changes to the alignment of the vertebrae and therefore a limited assessment. A low head and neck position leads to an increase in the distances between the spinous processes and could influence the evaluation of radiographs especially if these are taken as part of a pre-purchase examination. During the radiographic examination of the spine the head and neck position should be standardised in order to reduce manipulation and misinterpretation through better comparability of such radiographs

Orientador: Marcio Ajudarte Lopes<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-08-28T00:44:23Z (GMT). No. of bitstreams: 1 LucenaMarkman_Renata_M.pdf: 960885 bytes, checksum: 639bd2b482bba1e49ed3111595f8f4da (MD5) Previous issue date: 2015<br>Resumo: Estudos sugerem que o tratamento radioterápico em região de cabeça e pescoço possa ser considerado um importante fator desencadeador da formação de calcificações em carótida. No entanto, evidências científicas para tal comprovação são limitadas. Portanto, os objetivos deste estudo foram identificar através de radiografias panorâmicas a prevalência de ateromas calcificados da carótida numa população com câncer de cabeça e pescoço antes e depois de serem submetidos à radioterapia e correlacionar com os aspectos sócio-demográficos e comorbidades destes pacientes. Foram selecionados, de forma retrospectiva, 180 pacientes tratados por radioterapia que tinham radiografias panorâmicas realizadas antes e após o término deste tratamento. Os dados clínicos foram coletados dos prontuários médicos. A análise das radiografias panorâmicas mostrou que 35% dos pacientes apresentaram ateromas calcificados da carótida. Não foi encontrada diferença significativa na prevalência de ateromas antes e após a radioterapia. Com relação aos achados clínicos, houve maior prevalência de acidentes vasculares cerebrais em pacientes com ateromas quando comparados aos pacientes que não apresentaram ateromas (p<0,05). Não foram observadas outras diferenças significativas com relação à idade, gênero, hipertensão arterial, diabetes mellitus, infarto agudo do miocárdio, localização do tumor e dose de radiação recebida. Sendo assim, podemos concluir que apesar da radioterapia não ter modificado a prevalência de ateromas calcificados da carótida nesta população estudada, esta alteração é frequentemente encontrada em pacientes com câncer de cabeça e pescoço. Portanto, é importante que os cirurgiões-dentistas fiquem atentos quanto à presença de ateromas em radiografias panorâmicas de pacientes com câncer de cabeça e pescoço<br>Abstract: Studies suggest that radiotherapy to the head and neck may be an important triggering factor for calcified carotid artery atheromas. However, scientific evidences to prove this matter are limited. Therefore, this essay aimed to identify the prevalence of calcified carotid artery atheromas observed by panoramic radiograph in a head and neck cancer population before and after radiotherapy and to correlate them with the sociodemographic features and comorbidities of these patients. For this research, 180 patients submitted to radiotherapy that had panoramic radiographs before and after this treatment, were selected retrospectively. Clinical data from these patients were collected from their medical records. The panoramic radiographs were examined and 35% of the patients demonstrated calcified carotid artery atheromas. There was no significant difference in the prevalence of atheromas before and after radiotherapy. According to clinical data, there was a greater prevalence of strokes in patients with calcified carotid artery atheromas when compared to patients who did not have atheromas (p<0.05). Differences related to age, gender, arterial hypertension, diabetes mellitus, acute myocardial infarctation, tumor location and radiotherapy dose were not observed. Thus, we can conclude that although radiotherapy did not alter the prevalence of calcified carotid artery atheromas in the studied population, this alteration is commonly found in head and neck cancer patients. Therefore, it is important that dentists be aware to the presence of calcified carotid artery atheromas in panoramic radiographs of head and neck cancer patients<br>Mestrado<br>Estomatopatologia<br>Mestra em Estomatopatologia

O objetivo do estudo foi correlacionar a presença de alterações radiográficas em quadris de pacientes portadores de dor no quadril a um grupo de pacientes sem dor no quadril. Foram avaliados 122 pacientes com dor no quadril, e 100 pacientes sem dor no quadril. Todos com idade entre 20 e 50 anos. Os pacientes foram submetidos a exames radiográficos, nas incidências AP de pelve ortostático, falso perfil de Lequesne, Dunn, Dunn 45° e Ducroquet. Os parâmetros avaliados foram inclinação e versão acetabular, ângulo CE de Wiberg, espaço articular superolateral, ângulo , ângulo de Lequesne, ângulo VCA, diferença entre o raio da cabeça e do colo femorais (off set), esfericidade da cabeça femoral e a presença de ressalto na transição da cabeça com o colo femoral. Concluiu-se que as melhores incidências para o diagnóstico de impacto femoroacetabular são AP de pelve ortostático, Dunn 45° e Ducroquet, e que as seguintes alterações estão correlacionadas com dor nos quadris: off set diminuído, ângulo aumentado, ângulo de Lequesne aumentado, ângulo CE de Wiberg diminuído, espaço articular diminuído e presença de ressalto na transição cabeça-colo femoral<br>This study aimed to compare two groups of patients, with and with out hip pain, and correlate them with the existence of radiograph alterations. Weve studied 122 patients with hip pain and 100 asymptomatic; the ages were between 20 to 50 years old in both groups. All patients were roentnographicaly studied in anteroposterior pelvis in orthostatic position, Lequesne false profile, Dunns, Dunns 45° and Ducroquets view. The radiograph parameters analized were the acetabular inclination and vertion, Wiberg CE angle, Lequesne VCA angle, Lequesnes antevertion angle (), angle, superior and lateral joint space, femoral off set, nonspherical of the femoral head and the presence of a bump on the head-neck transition. We conclude that the best incidences to diagnosis of femoroacetabular impingement are AP pelvis orthostatic, Dunn 45° and Ducroquet. The following alterations are correlate with hip pain: lower off set, higher angle, higher Lequesne angle, lower CE angle of Wiberg, lower articular space and bump in the femoral head-neck transition

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-08-26T10:42:03Z No. of bitstreams: 0<br>Made available in DSpace on 2016-08-26T10:42:03Z (GMT). No. of bitstreams: 0<br>Para avaliar os níveis de exposição e a dose absorvida em pacientes submetidos a exames de tomografia computadorizada, TC, é necessário calcular os índices de dose em medições com um simulador de PMMA, ou cheio de água. O simulador deve ser capaz de reproduzir as características de absorção e espalhamento do corpo ou parte do corpo humano em um campo de radiação. As grandezas específicas em TC: índice de kerma livre no ar (Ca,100), índice de kerma no ar ponderado (CW), índice de kerma no volume total (Cvol) e produto kerma no ar-comprimento (PKL) devem ser determinadas e comparadas com os níveis de referência já existentes na literatura. Neste trabalho foi desenvolvido um simulador pediátrico craniano, já que no Brasil os níveis de referência para diagnósticos (NRDs) disponíveis foram determinados baseados em um simulador padrão adulto. O simulador desenvolvido inovou em sua construção apresentando materiais que simulam a calota craniana em osso cortical (alumínio) e osso esponjoso (PVC). O seu interior foi preenchido com água destilada. As dimensões foram escolhidas de acordo com as recomendações da Organização Mundial da Saúde e do International Commission on Radiation Units, para o tamanho da cabeça de uma criança de 0 a 5 anos: 160 mm de diâmetro e 155 mm de altura. A calota craniana tem uma espessura de 4 mm e diâmetro interno de 111,9 mm. Para avaliar seu comportamento foram realizados testes em laboratórios e em feixes clínicos. Os resultados apresentaram uma atenuação de até 23% na utilização dos materiais que simulam a calota craniana evidenciando que os valores adotados para os cálculos de NRD podem estar superestimando a dose recebida por pacientes pediátricos. Percebe-se que a dose recebida em exames de crânio apresenta uma distribuição diferente por ser parcialmente atenuada e/ou retroespalhada pela calota craniana, o que não é considerado ao se utilizar o simulador constituído apenas de PMMA.<br>Tese (Doutorado em Tecnologia Nuclear)<br>IPEN/T<br>Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Thesis (M.S.)--University of Missouri-Columbia, 2008.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 19, 2009) Includes bibliographical references.

A necrose asséptica da cabeça do fêmur (NACF) em cães é uma doença auto limitante do quadril em desenvolvimento, caracterizada por uma necrose asséptica, seguida por fratura subcondral, fragmentação, revascularização e remodelação na cabeça femoral. A etiologia da doença é obscura. A radiografia é a modalidade de imagem padrão utilizada para diagnosticar a doença em cães. Foi realizado um estudo retrospectivo de janeiro de 2000 até janeiro de 2010 nas radiografias de coxal com NACF nos cães atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Radiografias com NACF foram reavaliadas e os graus de alterações radiográficas foram correlacionados a raça, sexo, idade, membro(s) acometido(s). Foi estudado também a evolução radiográfica dos pacientes que tinham mais de um exame realizado. Analisando os resultados, observou-se que as três principais raças acometidas foram Poodles, Yorkshires e Pinschers. A NACF acomete principalmente animais jovens e de pequeno porte, porém no estudo houve um animal de grande porte e alguns animais com idade avançada. Não houve uma predisposição sexual. Com relação aos membros acometidos, notou-se que o grau 5 da doença apresenta maior incidência no membro pélvico direito e ao estudar a evolução da NACF, observou-se tratar de uma doença progressiva e de evolução lenta. Foram avaliadas imagens em filme radiográfico e imagens digitalizadas, sendo possível fazer uma comparação entre os dois métodos. Todas as imagens digitalizadas foram encontradas, ao contrário das imagens em filme radiográfico, demonstrando a facilidade e rapidez que a digitalização pode trazer.<br>Aseptic necrosis of the femoral head (ANFH) in dogs is a self limiting disease of the developing hip, characterized by an aseptic necrosis, followed by subchondral fracture, fragmentation, revascularization and remodeling of the femoral head. The etiology of the disease is unclear. In dogs the standard imaging modality is radiography. A retrospective study from January 2000 to January 2010 of ANFH cases attended at the Veterinary Hospital of the University of Sao Paulo was done. Radiographs of the hips diagnosed with ANFH where reexamined, the degree of changes established correlating data with breed, gender, age, and affected member. The three major breeds involved were Poodles, Yorkshires and Pinschers. The ANFH mainly affects young and small animals, but in this study there was one large animal and some animals with advanced age. There was no sexual predisposition. In the affected limbs, it was noted that the grade 5 of the disease has a higher incidence in the right limb. In patients with more than one examination evolution of the radiographic changes was analyzed. No regression of radiographic changes was registered and ANFH showed to be a progressive disease with slow evolution. To work with conventional and digital images showed no difficulty in reading but a substantial portion of conventional images were not found.

Dans le cadre de la Fusion par Confinement Inertiel, la maîtrise de la propagation des faisceaux laser intenses, qui se propagent dans le plasma sous-dense d'une cavité d'ignition, reste un enjeu majeur. En effet, durant leur propagation, les faisceaux vont modifier les paramètres du plasma, ces paramètres contrôlant eux-mêmes la propagation. Cette rétroaction entre le plasma et le laser est potentiellement instable et produit de l'autofocalisation, de la filamentation, etc. Ces mécanismes peuvent alors dégrader fortement la propagation et in fine l'uniformité du dépôt d'énergie recherché.Dans cette étude, expérimentale et numérique, nous nous intéressons à la propagation d'un filament laser (tache focale d'une dizaine de micromètres, impulsion de 1,5 ns et d'intensité variant de 1014 W.cm-2 à 1016 W.cm-2) dans un milieu très sous dense (quelques pour-cents de la densité électronique critique). Deux expériences ont été réalisées sur l'installation de puissance LULI2000 et ont permis à la fois d'observer la transmission laser et de caractériser les gradients de température. Ces gradients sont produits par le transport électronique et influencent la réponse du plasma au laser. Afin de modéliser le rôle des gradients de température dans les instabilités d'auto-focalisation et de filamentation, nous avons associé un code d'hydrodynamique-radiative (FCI2) à un code détaillé de propagation (Héra). Pour compléter les observables précédentes, nous avons aussi mis en œuvre un diagnostic de déflectométrie protonique. Ce diagnostic permet de mesurer les champs électriques présents dans le plasma, ces champs étant issus du chauffage et de l'interaction laser. Un nouvel outil, associant le code de propagation laser et un code Monte-Carlo de transport de protons, a donc été mis en place pour modéliser les déflexions des protons. Cet outil ouvre en plus de nouvelles perspectives pour discuter de l'influence des effets 3D dans l'exploitation de ce diagnostic. Les résultats obtenus confirment l'intérêt à sonder les champs électriques au cœur même du plasma pendant la propagation laser<br>The understanding and the control of high-power laser propagation into under-dense plasma is important to achieve inertial confinement fusion. During this process, the interaction of the laser with the plasma filling the hohlraum can lead to significant losses of laser energy which prevent ignition. Self-focusing or filamentation of the laser light is one of these phenomena which are desired to be mitigated since they also affect the uniformity of the laser illumination on the hohlraum wall.In order to improve our understanding of the laser-plasma interaction phenomena at play, we describe an experimental and numerical study involving an intense laser pulse between 1014 W.cm-2 and 1016 W.cm-2 , and which interacts with millimetric and under-dense plasma (having density of few % of the critical density). This work presents two experiments fielding a series of diagnostics aimed at well characterizing the laser propagation (Hisac camera) together with heat deposition in plasmas using Thomson scattering. Experimental results will be presented and discussed in the light of detailed simulations performed with the 3D laser propagation code Hera. In order to take into account the temperature gradients within the plasma during the laser propagation, Hera (laser propagation code) and FCI2 (radiation-hydrodynamic code) have been coupled. Besides, proton radiography has been used in order to access to electric fields. The measurements led to the implementation of a new and promising numerical tool using the Hera and Diane codes (Diane is a Monte Carlo particle tracing code). 3D proton radiography modelling opens new possibilities for users of this temporally and spatially resolved diagnostic

Nesta pesquisa foi comparada a diferença das medidas obtidas utilizando-se a análise cefalométrica do perfil tegumentar tendo como base a análise facial de Arnett relacionada à Horizontal Verdadeira com a análise cefalométrica do perfil tegumentar feita a partir do Plano de Frankfurt. Utilizamos 140 radiografias cefalométricas requisitadas como parte de documentação ortodôntica, obtidas de pacientes com idade variando de 06 a 49 anos, sendo 64 do sexo masculino e 76 do sexo feminino, pertencentes ao arquivo do IOM - (Instituto de Odontologia Multidisciplinar) ? RJ. As radiografias cefalométricas em norma lateral foram obtidas pelo mesmo operador, obedecendo ao protocolo adotado pelo IOM. Todos os pacientes foram orientados a assumir a Posição Natural da Cabeça, tendo como referência um espelho posicionado a frente e a Linha Vertical Verdadeira foi obtida por meio da utilização de um fio metálico unido à um prumo de chumbo, posicionado próximo à margem anterior do chassi porta-filme, de forma que apareça à frente do perfil tegumentar do paciente. A partir das medidas lineares obtidas nas Análises Cefalométricas dos Tecidos Moles, foram realizadas análises estatísticas visando dois objetivos: comparar as medidas de A à I obtidas nos traçados (um utilizando como referência uma perpendicular ao Plano Horizontal de Frankfurt e o outro à Linha Vertical Verdadeira) e analisar os resultados comparativamente. Após a análise estatística (Kolmogorov-Smirnov, para distribuição normal de dados; t-Student para amostras emparelhadas e teste não paramétrico de Wilcoxon) e a interpretação dos resultados obtidos, concluímos que houve diferenças significantes entre as formas de medidas das variáveis A, B, C, D, F, G e I, pois o valor do nível descritivo (p-valor) se apresentou abaixo de 0,05. Entretanto para as medidas E e H o valor do nível descritivo (p-valor) se apresentou maior que 0,05, demonstrando não haver diferenças significantes entre as formas dessas medidas. As correlações entre as medidas apresentadas estabelecidas pela análise facial de Arnett, de acordo com este estudo, não deverão ser utilizadas em pacientes que se submeteram à radiografias cefalométricas realizadas a partir do Plano Horizontal de Frankfurt, salvo no caso da distância interlabial, representada pela medida H, que além de não apresentar diferenças significantes neste estudo, não tem, segundo a análise de Arnett, correlação com nenhuma outra medida.<br>In this research a comparison was made between the differences in measurements obtained using the soft tissue profile?s cephalometric analysis based on Arnett?s facial analysis related to the true vertical with the cephalometric analysis of soft tissue profile based on the Frankfurt Plan. A total of 140 lateral cephalometric radiographs were used as part of the orthodontic documentation, taken from patients whose ages ranged from 06 to 49 years of age, of these 64 males and 76 females, being part of the files of the IOM (Instituto de Odontologia Multidisciplinar do Rio de Janeiro). The lateral cephalometric radiographs were obtained from the same operator obeying the protocols adapted by the IOM. All patients were oriented to place themselves in the Natural Head Posture using, as a reference, a mirror in front of then and the true vertical line was obtained using a metal wire and a plumb-line, placed close to the frontal chassis of the film chamber, in such a way that it appears in front of the soft tissue profile of the patient. Parting from the lineal measurements obtained from the Cephalometric Analyses of the Soft Tissues statistical analyses were made relating to two objectives: to compare the measurements from A to I obtained from the drafts/ sketches (one using as it reference a perpendicular to the Frankfurt Horizontal Plane and the other the True Vertical Line), comparatively analyse these results. After the statistical analysis (Kolgomorov Smirnov) for a normal data distribution: t-student for matched pairs and the no-parametric Wilcanox test) and the analysis of the results obtained, it was concluded that there were significant differences between the forms of the measurements of the variables A, B, C, D, F, G and I since the descriptive value (p-value) was below 0,05. The measurements for E and H, however, being over 0,05, showing than there were no significant differences between these forms of measurement. The correlation between the demonstrated measurements established by Arnett?s facial analysis, in accordance with this study, should not be used in patients who have undergone lateral cephalometric radiograph initiated on the basis of the Frankfurt Horizontal Plane except in the case of interlabial distance represented by the measurement H, which even differences in this study, does not have, according to Arnett?s studies, correlations with any other measurements.

The influence of processing and process parameters plays a key role for the Aluminium foundry and transport industries as it affects the quality and soundness of the cast products. Particularly, the choice of a process chain in Aluminium foundry, otherwise of process parameters, influences the reject rates, hence casting costs, the process yield and the production rate. The process chain in Aluminium foundry is a complex sequence of processes and the final casting quality depends on many parameters. Several aspects of this subject are still not fully understood. The motivation of the research presented in this doctoral thesis work was, therefore, to fill this gap in knowledge. The study has aimed at understanding the influence of various process and process parameters of foundry on the quality of aluminium alloy castings and, in particular, Al-Si based castings. A literature review and a sufficient background of previously reported results on the influence of processing and process parameters on the quality of aluminium alloy castings, physical fundamentals as well as industrial challenges, motivation and goals were carried out. Special attention in Aluminium process chain has been given to: The modification of aluminium-silicon cast alloys: before casting aluminium alloys, the molten metal can be treated in order to improve the microstructure and properties of alloys by addition of small quantities of certain "modifying" elements. The pouring of molten metal into the mould: this is one of the critical steps in foundry technology, since the behaviour of the liquid and its subsequent solidification and cooling determine whether the cast shape will be properly formed, internally sound and free from defects. The chill casting processes, such as gravity, low-pressure and high-pressure die casting processes: the essential feature of chill casting is the use of permanent metal moulds, into which the molten alloy is either poured directly or injected under pressure, giving rise to the separate processes of gravity and low/high pressure die casting. Permanent moulds offer obvious advantages in terms of simplicity of production for large quantities of parts, but are subject to limitations yet to be discussed. The heat treating process applied to high-pressure die castings: conventional die castings are utilised to produce many products but unfortunately the presence of porosity limits the application. In addition to porosity, the microstructure inherent with conventional die casting could not meet the mechanical requirements needed for many applications. Subsequent heat treating, which can positively alter the microstructure, is rarely possible due to defects that emerge during thermal processing, such as blistering.

Fong, Kwan Ying.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2010.<br>Includes bibliographical references (leaves 90-103).<br>Abstracts in English and Chinese.<br>Chapter Chapter 1: --- "Introduction, problems and objectives" --- p.1<br>Chapter 1.1 --- Introduction --- p.1<br>Chapter 1.2 --- Problems --- p.3<br>Chapter 1.3 --- Objectives --- p.3<br>Chapter Chapter 2: --- Background --- p.4<br>Chapter 2.1. --- Head and Neck Cancer --- p.4<br>Chapter 2.2 --- Diagnostic Imaging of Head and Neck Cancer --- p.5<br>Chapter 2.3. --- Magnetic Resonance Imaging- Physics --- p.8<br>Chapter 2.3.1 --- Nuclear Magnetic Resonance Principle --- p.8<br>Chapter 2.3.2 --- Proton Magnetic Resonance Imaging --- p.8<br>Chapter 2.3.3 --- Relaxation --- p.12<br>Chapter 2.3.4 --- Tl- and T2-weighted Imaging --- p.12<br>Chapter 2.3.5 --- Diffusion Weighted Imaging (DWI) --- p.13<br>Chapter 2.3.6 --- Magnetic Resonance Spectroscopy- Single Voxel Spectroscopy and Chemical Shift Imaging --- p.15<br>Chapter Chapter 3: --- Diffusion-weighted imaging in the evaluation head of and neck cancer --- p.21<br>Chapter 3.1 --- Introduction - Diffusion-Weighted Imaging in Tumors --- p.21<br>Chapter 3.2 --- DWI of Nasopharyngeal Carcinoma --- p.22<br>Chapter 3.2.1 --- Introduction and Objectives --- p.22<br>Chapter 3.2.2. --- Methods --- p.23<br>Chapter 3.2.3. --- Results --- p.27<br>Chapter 3.2.4 --- Discussion --- p.31<br>Chapter 3.3 --- DWI of Primary Tumors: Comparison of NPC with Squamous Cell Carcinoma and Extra-nodal Non-Hodgkin Lymphoma --- p.33<br>Chapter 3.3.1 --- Introduction and Objectives --- p.33<br>Chapter 3.3.2. --- Methods --- p.34<br>Chapter 3.3.3. --- Results --- p.35<br>Chapter 3.3.4 --- Discussion --- p.42<br>Chapter 3.3.5 --- Summary of DWI in Head and Neck Cancer --- p.44<br>Chapter Chapter 4: --- Chemical shift imaging of head and neck tumors --- p.45<br>Chapter 4.1 --- Introduction - Single Voxel Spectroscopy and Chemical Shift Imaging --- p.45<br>Chapter 4.2 --- CSI - Methods Used to Reduce Magnetic Field Inhomogeneity --- p.48<br>Chapter 4.3 --- Phantom studies - CSI Experiments Using Phantoms --- p.51<br>Chapter 4.3.1 --- Introduction and Objectives --- p.51<br>Chapter 4.3.2. --- Methods --- p.51<br>Chapter 4.3.3 --- Experiment and MR Protocol --- p.54<br>Chapter 4.3.4 --- Data Analysis --- p.58<br>Chapter 4.3.5 --- Phantom Experimental Results --- p.59<br>Chapter 4.3.6 --- Discussion and Conclusion on Phantom Experiments --- p.69<br>Chapter 4.4 --- In vivo CSI Study of Human Head and Neck Tumors --- p.72<br>Chapter 4.4.1 --- Introduction and Objectives --- p.72<br>Chapter 4.4.2 --- Patient Selection --- p.73<br>Chapter 4.4.3 --- MRI and CSI Protocol --- p.73<br>Chapter 4.4.4 --- Data Analysis --- p.74<br>Chapter 4.4.5 --- Results from CSI on Patients --- p.74<br>Chapter 4.4.6 --- Discussion and Conclusion of CSI on Patients --- p.81<br>Chapter Chapter 5: --- "Summary, conclusion and future studies" --- p.87<br>Chapter 5.1 --- Summary --- p.87<br>Chapter 5.2 --- Conclusion --- p.89<br>Chapter 5.3 --- Future Studies --- p.89<br>References --- p.90<br>Publications --- p.104

Pathologische Veränderungen der Wirbelsäule können zur Verkleinerung der Foramina intervertebralia der Halswirbelsäule sowie zur Verkürzung der Abstände zwischen den Dornfortsätzen der Brustwirbelsäule führen. Eine Veränderung der Kopf-Hals-Haltung kann ebenfalls die Dimension der Foramina intervertebralia sowie die Abstände zwischen den Dornfortsätzen beeinflussen. Die Bestimmung des Einflusses der Kopf-Hals-Haltung auf die genannten Parameter bei der radiologischen Darstellung der Wirbelsäule war deshalb das Ziel der vorliegenden Arbeit. In drei unterschiedlichen Kopf-Hals-Haltungen wurde die Halswirbelsäule von 25 klinisch unauffälligen Pferden im laterolateralen Strahlengang dargestellt. Laterolaterale Röntgenaufnahmen der Brustwirbelsäule von 23 Pferden ohne klinische Anzeichen einer Erkrankung der Wirbelsäule wurden ebenfalls in drei verschiedenen Kopf-Hals-Haltungen angefertigt. Die Auswertung dieser Aufnahmen erfolgte mit Hilfe von neu entwickelten Messmethoden, die eine hohe Reproduzierbarkeit aufwiesen. Auf den Aufnahmen der Halswirbelsäule wurde die Länge der Wirbelkörper und die Dimension der Foramina intervertebralia bestimmt. Zusätzlich wurden die Winkel zwischen angrenzenden Halswirbeln ermittelt. Der Abstand zwischen benachbarten Dornfortsätzen sowie die Breite der Dornfortsätze wurden für die Auswertung der Aufnahmen der Brustwirbelsäule gemessen. Für eine exaktere Auswertung der Aufnahmen der Brustwirbelsäule wurde ein spezieller Bildfilter entwickelt, der durch eine bessere Detailerkennbarkeit zu einer genaueren Messung der Streckung führte. Sowohl für die Breite der Dornfortsätze als auch für die Länge der Wirbelkörper der Halswirbel konnten keine signifikanten Unterschiede zwischen den Röntgenaufnahmen in den verschiedenen Kopf-Hals-Haltungen gefunden werden. Beide Strecken dienten zur Überprüfung des Versuchsaufbaus, um andere Ursachen für eine unterschiedliche Größe der Messstrecken auszuschließen. Die Foramina intervertebralia waren bei tiefer Kopf-Hals-Haltung signifikant größer als bei den anderen beiden Kopf-Hals-Haltungen (p < 0,05). Zwischen hoher und physiologischer Kopf-Hals-Haltung stellten sich nur die Foramina intervertebralia zwischen sechstem und siebten Halswirbel unterschiedlich groß dar (p < 0,05). Die Abstände zwischen angrenzenden Brustwirbeln waren vom achten bis zum vierzehnten Dornfortsatz in tiefer Kopf-Hals-Haltung größer als in den beiden anderen Kopf-Hals-Haltungen (p < 0,05). Diese Abstände nahmen insgesamt von kranial nach kaudal ab (p < 0,05) ab. Der zwölfte Dornfortsatz diente dabei zur Identifizierung der anderen, da er sich signifikant von den schmaleren kranialen und den breiteren kaudalen Dornfortsätzen unterschied (p < 0,01). Die Kopf-Hals-Haltung während der radiologischen Untersuchung beeinflusst sowohl die Dimension der Foramina intervertebralia als auch den Abstand zwischen den Dornfortsätzen. Deshalb sollte diese bei der Auswertung radiologischer Aufnahmen immer berücksichtigt werden. Die Foramina intervertebralia stellten sich bei tiefer Kopf-Hals-Haltung am größten dar und können somit in dieser am besten beurteilt werden, jedoch kommt es zu einer Veränderung der Anordnung der Wirbel, so dass diese nur noch eingeschränkt beurteilt werden können. Eine tiefe Kopf-Hals-Haltung führt zur Vergrößerung der Abstände zwischen den Dornfortsätzen und kann somit die Beurteilung von Röntgenaufnahmen der Brustwirbelsäule, gerade im Rahmen einer Kaufuntersuchung, beeinflussen. Die Kopf-Hals-Haltung bei der Anfertigung von Röntgenaufnahmen der Wirbelsäule sollte standardisiert werden, um durch verbesserte Vergleichbarkeit Manipulationen und Fehlinterpretationen einzuschränken.:1 Einleitung ................................................................................................................................. 1 2 Hypothesen .............................................................................................................................. 3 3 Eigene wissenschaftliche Orginalarbeiten ....................................................................... 4 3.1 Publikation 1: ................................................................................................................. 4 Die Bedeutung der Kopf-Hals-Haltung bei der röntgenologischen Darstellung der Foramina intervertebralia das Pferdehalses in der seitlichen Projektion ........................ 4 3.2 Publikation 2: ............................................................................................................... 25 Influence of head and neck position on radiographic measurement of distances between thoracic spinous processes in clinically sound horses .................................... 25 4 Diskussion .............................................................................................................................. 45 4.1 Ziele der Arbeit............................................................................................................. 45 4.2 Auswahl der Pferde ...................................................................................................... 45 4.3 Position der Pferde während der Untersuchungen ....................................................... 46 4.4 Röntgenologische Darstellung der Wirbelsäule der Pferde .......................................... 47 4.5 Auswertung der röntgenologischen Aufnahmen der Halswirbelsäule ......................... 49 4.6 Auswertung der röntgenologischen Aufnahmen der Brustwirbelsäule ........................ 51 4.7 Ergebnisse der Messungen der Halswirbelsäule .......................................................... 52 4.8 Ergebnisse der Messungen der Brustwirbelsäule ......................................................... 53 4.9 Klinische Relevanz für die röntgenologische Untersuchung des Halses ..................... 55 4.10 Klinische Relevanz für die röntgenologische Untersuchung des Rückens .................. 56 4.11 Abschließende Betrachtung .......................................................................................... 58 6 Zusammenfassung ............................................................................................................... 60 7 Summary ................................................................................................................................ 62 8 Literaturverzeichnis ............................................................................................................ 64 Danksagung ........................................................................................................................................ 71<br>Pathological changes of the spine can lead to reduction of the intervertebral foramina dimensions in the cervical spine and to shortening of the distances between the spinous processes in the thoracic spine. However, alteration of the head and neck position influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Determining the influence of the head and neck position on these parameters during radiological examination of the equine spine was the aim of this study. In three different head and neck positions lateral-lateral views of the cervical spine in 25 clinically sound horses were radiographically obtained. Lateral-lateral radiographs of the thoracic spine from 23 horses lacking clinical signs of spine diseases were taken in three different head and neck positions. Evaluation of the radiographs was carried out with newly developed measurement techniques providing high reproducibility. On the radiographs of the cervical spine the length of the vertebral bodies and the dimension of the intervertebral foramina were measured. Additionally, the angles between adjacent cervical vertebrae were determined. The distances between adjacent spinous processes and the width of the spinous processes were measured for evaluating the radiographs of the thoracic spines. For a more accurate evaluation of the thoracic spine radiographs a purpose-built image filter was developed, which provided more accurate measurement of the distances through better detail recognition. No significant differences were found for the width of the spinous processes of the thoracic vertebrae and the length of vertebral bodies of the cervical vertebrae between the radiographs taken in the three different head and neck positions. Both these distances were used to verify the experimental set-up to rule out other causes for differences in the measured distances. The intervertebral foramina were significantly wider in the low head and neck position than in the other two head and neck positions (p < 0.05). Between the high and the free head and neck position only the intervertebral foramina of the sixth and seventh cervical vertebrae showed different dimensions (p< 0.05). The distances between the adjacent thoracic vertebrae from the eighth to the fourteenth spinous processes were wider in the low head and neck position compared to the other two head and neck positions (p < 0.05). Altogether, these distances decreased from cranial to caudal (p < 0.05). The twelfth spinous process served for numerical identification of the other spinous processes due to its significant difference in width to the narrower cranial and broader caudal spinous processes (p < 0.05). The head and neck position during radiographic examination influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Therefore, it should always be considered when evaluating radiographs. In the low head and neck position the intervertebral foramina turned out to be the widest and could be best assessed. However, this resulted in changes to the alignment of the vertebrae and therefore a limited assessment. A low head and neck position leads to an increase in the distances between the spinous processes and could influence the evaluation of radiographs especially if these are taken as part of a pre-purchase examination. During the radiographic examination of the spine the head and neck position should be standardised in order to reduce manipulation and misinterpretation through better comparability of such radiographs.:1 Einleitung ................................................................................................................................. 1 2 Hypothesen .............................................................................................................................. 3 3 Eigene wissenschaftliche Orginalarbeiten ....................................................................... 4 3.1 Publikation 1: ................................................................................................................. 4 Die Bedeutung der Kopf-Hals-Haltung bei der röntgenologischen Darstellung der Foramina intervertebralia das Pferdehalses in der seitlichen Projektion ........................ 4 3.2 Publikation 2: ............................................................................................................... 25 Influence of head and neck position on radiographic measurement of distances between thoracic spinous processes in clinically sound horses .................................... 25 4 Diskussion .............................................................................................................................. 45 4.1 Ziele der Arbeit............................................................................................................. 45 4.2 Auswahl der Pferde ...................................................................................................... 45 4.3 Position der Pferde während der Untersuchungen ....................................................... 46 4.4 Röntgenologische Darstellung der Wirbelsäule der Pferde .......................................... 47 4.5 Auswertung der röntgenologischen Aufnahmen der Halswirbelsäule ......................... 49 4.6 Auswertung der röntgenologischen Aufnahmen der Brustwirbelsäule ........................ 51 4.7 Ergebnisse der Messungen der Halswirbelsäule .......................................................... 52 4.8 Ergebnisse der Messungen der Brustwirbelsäule ......................................................... 53 4.9 Klinische Relevanz für die röntgenologische Untersuchung des Halses ..................... 55 4.10 Klinische Relevanz für die röntgenologische Untersuchung des Rückens .................. 56 4.11 Abschließende Betrachtung .......................................................................................... 58 6 Zusammenfassung ............................................................................................................... 60 7 Summary ................................................................................................................................ 62 8 Literaturverzeichnis ............................................................................................................ 64 Danksagung ........................................................................................................................................ 71

Undesirable work factors, such as awkward upper body postures and repetitive arm motion, in the workplace can lead to upper extremity pain. Research suggests that these work-related factors, and subsequent rotator cuff fatigue, may cause the subacromial space (the space between the inferior acromion surface and superior humerus) of the shoulder to decrease. Reducing this space can create impingement of the interposed tissues, which causes shoulder pain. The aim of this study was to examine superior humeral head excursion and changes in the width of the subacromial space (acromio-humeral interval) after fatiguing the rotator cuff musculature. Four anterior-posterior radiographs of the glenohumeral joint at arm abduction angles of 0˚, 45˚, 90˚ and 135˚ were taken before and after a fatiguing task. The fatiguing task was a simulated job task requiring shoulder flexion/abduction and internal/external rotation, with the intention of exhausting the entire rotator cuff. The position of the humeral head with respect to the glenoid cavity was significantly affected both by arm angle and fatigue state; the mean humeral superior excursion following fatigue was 0.63±1.76mm. In the pre-fatigued state, increasing arm angle was related to superior translation until 90˚, after which the humeral head moved inferiorly to a more central position. In the post-fatigued state, the inability of the rotator cuff to centralize the humeral head led to increasing translations with higher elevations. Although the magnitude of translation in this study was smaller than seen in patients with rotator cuff tears, continuous overhead work demonstrably created rotator cuff fatigue, which apparently inhibited the ability of the shoulder musculature to resist upward translation of the humerus. Therefore, jobs that require overhead and repetitive work arguably put the worker at greater risk for superior translation of the humerus and subsequent related tissue damage.

no<br>Introduction In the face of growing demand in radiology, skill mix initiatives have sought to improve and expand service provision. Within the UK radiographer reporting is now widespread, although the growth in computerised tomography (CT) head reporting has not been as rapid as anticipated. The literature in this area is limited, but case studies have highlighted the successful implementation of this training through new radiographer roles in practice. Method A cross-sectional survey was developed to elicit information from radiographers and managers on their experiences before, during and after post-graduate training in CT head reporting. Results Seventy one responses were received comprising 48 past students (n = 48/111; 43.2%) and 23 service managers (n = 23/67; 34.3%). Key factors for the development were personal continual professional development for students and departmental need for managers. Challenges during training included a lack of study time due to staff shortages and access to radiologist mentors. Only 48.8% of students responding have gone on to use the new skills in practice cited reasons include staff shortages, resistance from radiologists and increase in radiological staffing. Conclusions This qualitative study has demonstrated that those trusts who have implemented CT head reporting have evidenced perceptible benefits for both the department and individuals. Those radiographers who are successfully reporting have shown themselves to be highly motivated and persistent in their development.