Made available in DSpace on 2014-10-09T12:34:23Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:32Z (GMT). No. of bitstreams: 0 / Este estudo teve como finalidade principal avaliar a qualidade de vida (QV) dos profissionais de saúde que compõem o serviço de radiodiagnóstico de um hospital da cidade de São Paulo. Além disso, objetivou conhecer o perfil desses profissionais, identificando as variáveis que podem influenciar a QV desses profissionais. Trata-se de um estudo descritivo e exploratório com abordagem quali-quantitativa. Os dados foram coletados usando os questionários: o instrumento abreviado de avaliação de QV - World Health Organization Quality of Life Instrument bref (WHOQOL-bref) da Organização Mundial da Saúde e um questionário sobre as variáveis de interesse: sociodemográficas, condições de trabalho e estilo de vida, ambos questionários auto-aplicáveis. A amostra foi constituída de 118 profissionais nas categorias de: médicos, tecnólogos/técnicos de radiologia, enfermeiros, técnicos e auxiliares de enfermagem, entre outros. A análise dos dados envolveu estatística descritiva, testes não paramétricos e o uso de um modelo de regressão linear. O grau de confiabilidade do instrumento foi avaliado por meio do Coeficiente Alfa de Cronbach (α). O WHOQOL-bref demonstrou ser um instrumento adequado, de aplicação fácil e rápida para a aferição da qualidade de vida; mostrou bom desempenho psicométrico e boa consistência interna (α=0,884). O estudo permitiu conhecer a percepção de qualidade de vida do grupo estudado. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Ce travail de thèse, réalisé à l'Institut Mathématiques de Bordeaux (IMB) de 2010 à 2015 sous la direction de Thierry Colin et Olivier Saut, décrit la création et le développement progressif d'un ensemble de théories, de techniques et d'outils liant l'imagerie médicale aux mathématiques appliquées dans le but d'envisager leur application clinique à courte échéance en oncologie. Cette thèse a tout d'abord consisté à optimiser les modèles spatiaux de croissance tumorale développés à l'IMB incluant des éléments microscopiques et macroscopiques obtenus par analyse des informations disponibles des examens d’imagerie. Plusieurs étapes ont été réalisées permettant de mieux appréhender la modélisation in vivo. Différents organes et types tumoraux ont été explorés, en particulier au niveau du poumon, du foie, et du rein. Ces localisations ont été successivement étudiées afin d’enrichir progressivement les modèles par les réponses qu'elles apportaient et répondre ainsi à la réalité clinique. De façon concomitante, des outils ont été intégrés au fur et à mesure afin de standardiser la démarche de recueil de données et permettre d'affiner l'évaluation thérapeutique par l'imagerie à l'aide de marqueurs numériques. L'implémentation de l'imagerie fonctionnelle dans une pratique clinique est ainsi devenue une réalité. Le but est à terme d’appliquer de façon prospective ces outils d'assistance en pratique quotidienne. La modélisation a été aussi appliquée en oncologie interventionnelle par l'étude de la distribution du champ électrique lors des électroporations de prostate et bientôt du foie. Ceci permettra de mieux contrôler les zones d'ablation et ainsi améliorer la sécurité et l'efficacité de ces traitements. Tout cela a permis d'envisager des projets cliniques combinant une part exploratoire impliquant la modélisation. Ces développements et leurs perspectives sont rapportés successivement dans ce manuscrit. / This work performed at the Institute of Mathematics of Bordeaux (IMB) from 2010 to 2015 under the direction of Thierry Colin and Olivier Saut describes the creation and gradual development of a set of theories, techniques and tools linking medical imaging and applied mathematics in order to consider their clinical application in the short term in oncology. The first goal was to optimize the spatial models of tumor growth developed at the IMB including microscopic and macroscopic elements obtained by analyzing the information available on imaging explorations. Several steps were performed to better understand the in vivo modeling. Various organs and tumor types were investigated, especially in the lung, liver, and kidney. These locations were studied successively to progressively enrich the model by the answers they brought and thus respond to clinical reality. Concomitantly, tools were integrated to standardize the data collection process and help to refine the therapeutic evaluation by imaging with digital markers. The implementation of functional imaging in clinical practice has become a reality. The goal is ultimately to apply prospectively these support tools in a daily practice. Modelling was also applied in interventional oncology for the study of the electric field distribution after percutaneous irreversible electroporation in the prostate and soon in the liver. This will allow a better control of the ablation areas and thereby improve the safety and efficacy of these treatments.

Abstract Neurosensory disturbance is a common complication of bilateral sagittal split osteotomy (BSSO). This study focuses on the evaluation of factors affecting neurosensory disturbance after BSSO. Furthermore, the study focuses on the measurement of neurosensory disturbance with easily available bedside tests, not only on evaluating the state of sensory disturbance at each follow-up, but also on predicting the potential for recovery. Moreover, panoramic radiography, computerized tomography (CT) and conventional spiral tomography are assessed on locating the mandibular canal. The study was carried out involving a total of 50 patients undergoing BSSO for the correction of mandibular deficiency. In addition, 20 voluntary healthy students participated in this study. Questionnaires, a battery of neurosensory tests and preoperative imaging of the mandibular canal were used. A high incidence of neurosensory disturbance of the lower lip and chin was found after BSSO. However, recovery of sensation occurred with increasing frequency during the follow-up, and after one year sensation of the lower lip and chin returned to the presurgical situation in most patients. A prolonged neurosensory disturbance was more frequent in older patients, in large surgical movements of the mandible and in cases where the inferior alveolar nerve was manipulated during surgery. The bedside tests used in this study correlated well with the patients' subjective evaluation of neurosensory disturbance, and the repeatability of these tests was good. Furthermore, the sensibility testing of the mandibular teeth correlated well with the other tests and patient's subjective evaluation. Four days after surgery, sensibility testing of the mandibular teeth was an efficient test alone to predict the recovery from neurosensory disturbance. On radiographic imaging, the risk for neurosensory disturbance after BSSO could not be predicted from the panoramic radiograph. Before BSSO, CT was the best method to visualize the buccolingual location of the mandibular canal. After BSSO, a clinical follow-up using a battery of mechano- and nociceptive tests in the examination of sensation of the lower lip and chin, sensibility testing of the teeth, and subjective evaluation is needed. CT should be a part of treatment planning of the patients with thin rami or severe asymmetries of the mandible.

This dissertation examines the history of modern Japan via a study of rentogen, or X-rays, in medical practice. Conventional milestones in Japan’s encounters with nuclear science all date from 1945: the atomic bombings of Hiroshima and Nagasaki that same year, the Bikini Atoll fallout incident in 1954, the construction of nuclear power plants from the late 1950s onwards, and most recently, the Fukushima Daiichi meltdown in 2011. All these events produced hibakusha – the Japanese term for survivors of nuclear-related accidents, or people suffering the effects of exposure to ionising radiation. In contrast, this project locates the first hibakusha in an earlier period, revealing a history of radiation exposure in Japan before the atomic bombings. It reaches into the late nineteenth and early twentieth centuries to find Japanese bodies exposed through the development of radiology. In modern Japan, as in Western Europe and America, X-rays constituted the first source of ionizing radiation that produced victims of burns, cancers, and deaths. This study highlights the political, social and cultural impact of modern Western medicine on Japanese society from the Meiji period onwards, showing how electric-powered machines and Western expertise came to define medical practice in the emergent field of radiology. / East Asian Languages and Civilizations

Although improved treatments have reduced the rates of acute complications from myocardial infarction, sequelae such as heart failure and sudden death threaten the future wellbeing of those patients. Secondary prevention after myocardial infarction is related to cardiovascular risk factors and the effect of the infarct on left ventricular function. Cardiovascular magnetic resonance imaging (CMR) is necessary to determine the size of the infarct scar and can with great precision determine left ventricular volumes, left ventricular ejection fraction, and deformation (strain and torsion). The purpose of this thesis was to improve on CMR methods to facilitate image acquisition and post processing in patients with high risk of coronary artery disease (CAD). In Paper 1, a three-dimensional phase-sensitive inversion-recovery (3D PSIR) sequence was modified to measure T1 during a single breath hold. The measured T1 values were used to extrapolate a map of T1 relaxation, which avoided the time-consuming manual determination of the inversion time. The data collection consisted of phantom experiments, Monte Carlo simulations of the effect of various heart rates, and clinical investigation of 18 patients with myocardial infarction. Scar images created with the modified sequence were compared to those created with the standard sequence. The 3D PSIR sequence was able to measure T1 relaxation with a high accuracy up to 800 ms, which is in the suitable range for scar imaging. Simulated arrhythmias showed that the method was robust and able to tolerate some variation in heart rate. The modified sequence provides measurements of inversion time that can be used to facilitate standard scar imaging or to reconstruct synthetic scar images. Images of infarct scar obtained with the 3D PSIR sequence bore striking similarity to images obtained with the standard sequence. In Paper 2, 125 patients with high risk of CAD were investigated using the displacement encoding with stimulated echoes (DENSE) sequence. Image segments with infarct scar area >50% (transmurality) could be identified with a sensitivity of 95% and a specificity of 80% based on circumferential strain calculated from the DENSE measurements. The DENSE sequence was also applied in other directions, but its sensitivity and specificity to detect scar was lower than when used for circumferential strain. In Paper 3, 90 patients with high risk of CAD were examined by DENSE, tagging with harmonic phase (HARP) imaging and cine imaging with feature tracking (FT), to detect cardiac abnormalities as manifested in end-systolic circumferential strain. Circumferential strain calculated with DENSE had higher sensitivity and specificity than the competing methods to detect infarction with transmurality >50%. Global circumferential strain measured by DENSE correlated better with global parameters such as left ventricular ejection fraction, myocardial wall mass, left ventricular end-diastolic and end-systolic volume; than strain measured by FT or HARP. In Paper 4, myocardial torsion was investigated using DENSE, HARP, and FT in 48 patients with high risk of CAD. Torsion measured by each of the three methods was correlated with other global measures such as left ventricular ejection fraction, left ventricular mass, and left ventricular end-diastolic and end-systolic volumes. The torsion measurements obtained with DENSE had a stronger relationship with left ventricular ejection fraction, left ventricular mass, and volumes than those obtained with HARP or FT. DENSE was superior to the other methods for strain and torsion measurement and can be used to describe myocardial deformation quantitatively and objectively.

Magnetic Resonance Imaging (MRI) has a high soft-tissue contrast with a high sensitivity for detecting pathological changes in the brain. Conventional MRI is a time-consuming method with multiple scans that relies on the visual assessment of the neuroradiologist. Synthetic MRI uses one scan to produce conventional images, but also quantitative maps based on relaxometry, that can be used to quantitatively analyse tissue properties and pathological changes. The studies presented here apply the use of synthetic MRI of the brain in different clinical settings. In the first study, synthetic MR images were compared to conventional MR images in 22 patients. The contrast, the contrast-to-noise ratio, and the diagnostic quality were assessed. Image quality was perceived to be inferior in the synthetic images, but synthetic images agreed with the clinical diagnoses to the same extent as the conventional images. Patients with early multiple sclerosis were analysed in the second study. In patients with multiple sclerosis, contrast-enhancing white matter lesions are a sign of active disease and can indicate a need for a change in therapy. Gadolinium-based contrast agents are used to detect active lesions, but concern has been raised regarding the long-term effects of repeated use of gadolinium. In this study, relaxometry was used to evaluate whether pre-contrast injection tissue-relaxation rates and proton density can identify active lesions without gadolinium. The findings suggest that active lesions often have relaxation times and proton density that differ from non-enhancing lesions, but with some overlap. This makes it difficult to replace gadolinium-based contrast agent injection with synthetic MRI in the monitoring of MS patients. Malignant gliomas are primary brain tumours with contrast enhancement due to a defective blood-brain barrier. However, they also grow in an infiltrative, diffuse manner, making it difficult to clearly delineate them from surrounding normal brain tissue in the diagnostic workup, at surgery, and during follow-up. The contrast-enhancing part of the tumour is easily visualised, but not the diffuse infiltration. In studies three and four, synthetic MRI was used to analyse the peritumoral area of malignant gliomas, and revealed quantitative findings regarding peritumoral relaxation changes and non-visible contrast enhancement suggestive of non-visible infiltrative tumour growth. In conclusion, synthetic MRI provides quantitative information about the brain tissue and this could improve the diagnosis and treatment for patients.

Background. Standard traditional parameters relied on for estimating the risk of disease recurrence after curative radiotherapy in prostate cancer are stage, Gleason score and PSA. Objectives. To elucidate the prognostic role of biomarkers: P-53, MIB-1, MVD, Bax and BCL2 in prostate cancer. Method. Cox proportional hazard model was used to estimate the risk of disease progression associated with these biomarkers and develop models based on traditional parameters only or incorporating biomarkers. Models were compared for their predictive potential using Akaike information criteria and concordance index. Results. Statistically significant associations were found between all biomarkers and risk of progression. MVD, Bax and Bax/BCL2 were independent predictors of outcome. Models incorporating biomarkers were superior to the traditional one in identifying patients at risk of local progression. Conclusions. Biomarkers may be useful in forecasting the risk of local recurrence following radiotherapy in prostate cancer patients. The results require validation in a separate cohort.

Problem. After two years of operation a review of the Rapid Palliative Radiotherapy Program revealed that only 17 family physicians in Eastern Ontario had used the program. Methods of investigation. This thesis consists of: (1) A systematic literature review of the relative effectiveness of a single fraction of radiotherapy to relieve painful bone metastases and (2) A survey of family physicians to assess their awareness of the Rapid Palliative Radiotherapy Program. Results. A single fraction of radiotherapy is of comparable effectiveness to multiple fraction radiotherapy treatment schedules in relieving painful metastatic bone disease (Odds Ratio: 1.13, 95% CI = 0.96 to 1.34). Only 18% of survey responders were aware of the RPRP. Conclusion. Improving family physician awareness of the Rapid Palliative Radiotherapy Program is the first step to improving utilization of the program and access for patients with painful metastatic bone disease to a proven, effective analgesic treatment.

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