334 resultados para image-making
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Résumé Ce travail vise à clarifier les résultats contradictoires de la littérature concernant les besoins des patients d'être informés et de participer à la prise de décision. La littérature insiste sur le contenu de l'information comme base de la prise de décision, bien qu'il existe des preuves que d'autres contenus sont importants pour les patients. La thèse essaie en outre d'identifier des possibilités de mieux répondre aux préférences d'information et de participation des patients. Les travaux ont porté en particulier sur les soins palliatifs. Une analyse de la littérature donne un aperçu sur les soins palliatifs, sur l'information des patients et sur leur participation à la prise de décisions thérapeutiques. Cette analyse résume les résultats d'études précédentes et propose un: modèle théorique d'information, de prise de décision et de relation entre ces deux domaines. Dans le cadre de ce travail, deux études empiriques ont utilisé des questionnaires écrits adressés à des personnes privées et à des professionnels de la santé, couvrant la Suisse et le Royaume Uni, pour identifier d'éventuelles différences entre ces deux pays. Les enquêtes ont été focalisées sur des patients souffrant de cancer du poumon. Les instruments utilisés pour ces études proviennent de la littérature afin de les rendre comparables. Le taux de réponse aux questionnaires était de 30-40%. La majorité des participants aux enquêtes estime que les patients devraient: - collaborer à la prise de décision quant à leur traitement - recevoir autant d'information que possible, positive aussi bien que négative - recevoir toutes les informations mentionnées dans le questionnaire (concernant la maladie, le diagnostic et les traitements), tenant compte de la diversité des priorités des patients - être soutenus par des professionnels de la santé, leur famille, leurs amis et/ou les personnes souffrant de la même maladie En plus, les participants aux enquêtes ont identifié divers contenus de l'information aux patients souffrant d'une maladie grave. Ces contenus comprennent entre autres: - L'aide à la prise de décision concernant le traitement - la possibilité de maintenir le contrôle de la situation - la construction d'une relation entre le patient et le soignant - l'encouragement à faire des projets d'avenir - l'influence de l'état émotionnel - l'aide à la compréhension de la maladie et de son impact - les sources potentielles d'états confusionnels et d'états anxieux La plupart des contenus proposés sont positifs. Les résultats suggèrent la coexistence possible de différents contenus à un moment donné ainsi que leur changement au cours du temps. Un modèle est ensuite développé et commenté pour présenter le diagnostic d'une maladie grave. Ce modèle est basé sur la littérature et intègre les résultats des études empiriques réalisées dans le cadre de ce travail. Ce travail analyse également les sources préférées d'information et de soutien, facteurs qui peuvent influencer ou faire obstacle aux préférences d'information et de participation. Les deux groupes de participants considèrent les médecins spécialistes comme la meilleure source d'information. En ce qui concerne le soutien, les points de vue divergent entre les personnes privées et les professionnels de la santé: généralement, les rôles de soutien semblent peu définis parmi les professionnels. Les barrières à l'information adéquate du patient apparaissent fréquemment liées aux caractéristiques des professionnels et aux problèmes d'organisation. Des progrès dans ce domaine contribueraient à améliorer les soins fournis aux patients. Finalement, les limites des études empiriques sont discutées. Celles-ci comprennent, entre autres, la représentativité restreinte des participants et les objections de certains groupes de participants à quelques détails des questionnaires. Summary The present thesis follows a call from the current body of literature to better understand patient needs for information and for participation in decision-making, as previous research findings had been contradictory. Information so far seems to have been considered essentially as a means to making treatment decisions, despite certain evidence that it may have a number of other values to patients. Furthermore, the thesis aims to identify ways to optimise meeting patient preferences for information and participation in treatment decisions. The current field of interest is palliative care. An extensive literature review depicts the background of current concepts of palliative care, patient information and patient involvement into treatment decisions. It also draws together results from previous studies and develops a theoretical model of information, decision-making, and the relationship between them. This is followed by two empirical studies collecting data from members of the general public and health care professionals by means of postal questionnaires. The professional study covers both Switzerland and the United Kingdom in order to identify possible differences between countries. Both studies focus on newly diagnosed lung cancer patients. The instruments used were taken from the literature to make them comparable. The response rate in both surveys was 30-40%, as expected -sufficient to allow stastical tests to be performed. A third study, addressed to lung cancer patients themselves, turned out to require too much time within the frame available. A majority of both study populations thought that patients should: - have a collaborative role in treatment-related decision-making -receive as much information as possible, good or bad - receive all types of information mentioned in the questionnaire (about illness, tests, and treatment), although priorities varied across the study populations - be supported by health professionals, family members, friends and/or others with the same illness Furthermore they identified various 'meanings' information may have to patients with a serious illness. These included: - being an aid in treatment-related decision-making - allowing control to be maintained over the situation - helping the patient-professional relationship to be constructed - allowing plans to be made - being positive for the patient's emotional state - helping the illness and its impact to be understood - being a source of anxiety - being a potential source of confusion to the patient Meanings were mostly positive. It was suggested that different meanings could co-exist at a given time and that they might change over time. A model of coping with the disclosure of a serious diagnosis is then developped. This model is based on existing models of coping with threatening events, as takeñ from the literature [ref. 77, 78], and integrates findings from the empirical studies. The thesis then analyses the remaining aspects apparent from the two surveys. These range from the identification of preferred information and support providers to factors influencing or impeding information and participation preferences. Specialist doctors were identified by both study populations as the best information providers whilst with regard to support provision views differed between the general public and health professionals. A need for better definition of supportive roles among health care workers seemed apparent. Barriers to information provision often seem related to health professional characteristics or organisational difficulties, and improvements in the latter field could well help optimising patient care. Finally, limitations of the studies are discussed, including questions of representativness of certain results and difficulties with or objections against questionnaire details by some groups of respondents.
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PURPOSE: To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography. MATERIALS AND METHODS: Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software. RESULTS: Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv. CONCLUSION: CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.
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BACKGROUND: Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. OBJECTIVE: To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. MATERIALS AND METHODS: Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI(vol) 4.8-7.9 mGy, DLP 37.1-178.9 mGy·cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. RESULTS: The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. CONCLUSION: Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone.
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Surgical decision-making in lumbar spinal stenosis involves assessment of clinical parameters and the severity of the radiological stenosis. We suspected that surgeons based surgical decisions more on dural sac cross-sectional area (DSCA) than on the morphology of the dural sac. We carried out a survey among members of three European spine societies. The axial T2-weighted MR images from ten patients with varying degrees of DSCA and morphological grades according to the recently described morphological classification of lumbar spinal stenosis, with DSCA values disclosed in half the assessed images, were used for evaluation. We provided a clinical scenario to accompany the images, which were shown to 142 responding physicians, mainly orthopaedic surgeons but also some neurosurgeons and others directly involved in treating patients with spinal disorders. As the primary outcome we used the number of respondents who would proceed to surgery for a given DSCA or morphological grade. Substantial agreement among the respondents was observed, with severe or extreme stenosis as defined by the morphological grade leading to surgery. This decision was not dependent on the number of years in practice, medical density or specialty. Disclosing the DSCA did not alter operative decision-making. In all, 40 respondents (29%) had prior knowledge of the morphological grading system, but their responses showed no difference from those who had not. This study suggests that the participants were less influenced by DSCA than by the morphological appearance of the dural sac. Classifying lumbar spinal stenosis according to morphology rather than surface measurements appears to be consistent with current clinical practice.
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The trabecular bone score (TBS) is a gray-level textural metric that can be extracted from the two-dimensional lumbar spine dual-energy X-ray absorptiometry (DXA) image. TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard bone mineral density (BMD) measurement. Based on experimental variograms of the projected DXA image, TBS has the potential to discern differences between DXA scans that show similar BMD measurements. An elevated TBS value correlates with better skeletal microstructure; a low TBS value correlates with weaker skeletal microstructure. Lumbar spine TBS has been evaluated in cross-sectional and longitudinal studies. The following conclusions are based upon publications reviewed in this article: 1) TBS gives lower values in postmenopausal women and in men with previous fragility fractures than their nonfractured counterparts; 2) TBS is complementary to data available by lumbar spine DXA measurements; 3) TBS results are lower in women who have sustained a fragility fracture but in whom DXA does not indicate osteoporosis or even osteopenia; 4) TBS predicts fracture risk as well as lumbar spine BMD measurements in postmenopausal women; 5) efficacious therapies for osteoporosis differ in the extent to which they influence the TBS; 6) TBS is associated with fracture risk in individuals with conditions related to reduced bone mass or bone quality. Based on these data, lumbar spine TBS holds promise as an emerging technology that could well become a valuable clinical tool in the diagnosis of osteoporosis and in fracture risk assessment.
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Synaptic plasticity involves a complex molecular machinery with various protein interactions but it is not yet clear how its components give rise to the different aspects of synaptic plasticity. Here we ask whether it is possible to mathematically model synaptic plasticity by making use of known substances only. We present a model of a multistable biochemical reaction system and use it to simulate the plasticity of synaptic transmission in long-term potentiation (LTP) or long-term depression (LTD) after repeated excitation of the synapse. According to our model, we can distinguish between two phases: first, a "viscosity" phase after the first excitation, the effects of which like the activation of NMDA receptors and CaMKII fade out in the absence of further excitations. Second, a "plasticity" phase actuated by an identical subsequent excitation that follows after a short time interval and causes the temporarily altered concentrations of AMPA subunits in the postsynaptic membrane to be stabilized. We show that positive feedback is the crucial element in the core chemical reaction, i.e. the activation of the short-tail AMPA subunit by NEM-sensitive factor, which allows generating multiple stable equilibria. Three stable equilibria are related to LTP, LTD and a third unfixed state called ACTIVE. Our mathematical approach shows that modeling synaptic multistability is possible by making use of known substances like NMDA and AMPA receptors, NEM-sensitive factor, glutamate, CaMKII and brain-derived neurotrophic factor. Furthermore, we could show that the heteromeric combination of short- and long-tail AMPA receptor subunits fulfills the function of a memory tag.
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Background: Shared decision making (SDM) is a process by which a healthcare choice is made jointly by the healthcare professional and the patient. SDM is the essential element of patient-centered care, a core concept of primary care. However, SDM is seldom translated into primary practice. Continuing professional development (CPD) is the principal means by which healthcare professionals continue to gain, improve, and broaden the knowledge and skills required for patient-centered care. Our international collaboration seeks to improve the knowledge base of CPD that targets translating SDM into the clinical practice of primary care in diverse healthcare systems. Methods: Funded by the Canadian Institutes of Health Research (CIHR), our project is to form an international, interdisciplinary research team composed of health services researchers, physicians, nurses, psychologists, dietitians, CPD decision makers and others who will study how CPD causes SDM to be practiced in primary care. We will perform an environmental scan to create an inventory of CPD programs and related activities for translating SDM into clinical practice. These programs will be critically assessed and compared according to their strengths and limitations. We will use the empirical data that results from the environmental scan and the critical appraisal to identify knowledge gaps and generate a research agenda during a two-day workshop to be held in Quebec City. We will ask CPD stakeholders to validate these knowledge gaps and the research agenda. Discussion: This project will analyse existing CPD programs and related activities for translating SDM into the practice of primary care. Because this international collaboration will develop and identify various factors influencing SDM, the project could shed new light on how SDM is implemented in primary care.
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This article studies the influence of the procedural justice resulting from participation in decision-making on employees' affective commitment in social enterprises. It also examines whether any potential link between participation and commitment is due to social exchange, as is the case with for-profit companies. The study is based on data from employees of French work integration social enterprises. The results confirm the positive relationship between procedural justice and affective commitment and the mediating role of perceived organizational support and leader-member exchanges. Managerial recommendations are then given to best maintain or increase employees' involvement in the decision-making processes of social enterprises.