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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Förebygger kirurgiska munskydd infektion hos patienten vid interventionell radiologi? : en litteraturöversikt / Surgical face masks as infection prevention in interventional radiology : a literature review

Wiippa, Beatrice, Azarnia, Sadaf January 2018 (has links)
Introduktion: Ett av röntgensjuksköterskans ansvarsområden är att förebygga spridning av vårdrelaterade infektioner, och inom interventionell radiologi innebär detta att arbeta med aseptisk teknik. Munskydd har varit standard inom kirurgi i ett århundrade men inom interventionell radiologi saknas nationella riktlinjer för dess användande, trots att den sterila tekniken i övrigt är densamma. Syfte: Syftet med denna litteraturöversikt var att klargöra huruvida kirurgiska munskydd kan förebygga infektion hos patienten vid interventionell radiologi. Metod: Studien genomfördes som en allmän litteraturöversikt enligt Friberg (2017) för att sammanställa kunskapsläget inom området. Tolv kvantitativa artiklar hittades genom systematisk litteratursökning i PubMed. Artiklarna kvalitetsgranskades, analyserades och resultatet presenterades i två huvudkategorier. Resultat: Munskydd har ingen påvisad effekt att förebygga postoperativa sårinfektioner vid kirurgi eller coronarangiografi men förhindrar till viss del spridning av bakterier. Slutsats: Forskningen på munskydd är begränsad vilket gör det svårt att dra några slutsatser. Fler studier som fokuserar på munskydds effektivitet inom interventionell radiologi behövs. Författarna anser att munskydd inom interventionell radiologi inte bör vara obligatoriskt utan upp till varje avdelning att från fall till fall bestämma huruvida det ska användas eller inte. / Introduction: One of the radiographer's responsibilities is to prevent the spread of healthcare-associated infections. In interventional radiology, this means working with aseptic technique. Surgical face mask protection has been the standard of surgery for a century, but in interventional radiology there are no national guidelines for its use, even though the sterile technique is the same. Aim: The aim of this study was to clarify whether surgical face masks prevent infection in patient in interventional radiology. Methodology: A literature review (Friberg, 2017) has been done to identify the current knowledge in the field. The study includes twelve quantitative articles collected through a systematic literature search in PubMed. After quality review the articles were analyzed and presented into two main categories. Result: Concerning postoperative wound infections, there is no strong evidence to prove that using surgical face masks prevents infections during surgery or coronary angiography. However, using such mask prevents the spread of bacteria to some extent. Conclusion: Research on oral protection is limited, making it difficult to draw any conclusions. A set of new tests are needed to identify the effect of using mask in today’s interventional radiology. Based on the results of the studies, it can be concluded that: generally, mouth protection within interventional radiology should not be mandatory. However, each radiology department need to consider the operating condition and status of the patient and decide if the personal should follow mouth protection process.
42

On-line C-arm intrinsic calibration by means of an accurate method of line detection using the radon transform / On-line C-arm Calibration intrinsèque "On-line" d'un C-arm par une méthode de détection de droite avec la transformée de Radon

Spencer, Benjamin 18 December 2015 (has links)
Les ``C-arm'' sont des systémes de radiologie interventionnelle fréquemment utilisés en salle d'opération ou au lit du patient. Des images 3D des structures anatomiques internes peuvent être calculées à partir de multiples radiographies acquises sur un ``C-arm mobile'' et isocentrique décrivant une trajectoire généralement circulaire autour du patient. Pour cela, la géométrie conique d'acquisition de chaque radiographie doit être précisément connue. Malheureusement, les C-arm se déforment en général au cours de la trajectoire. De plus leur motorisation engendre des oscillations non reproductibles. Ils doivent donc être calibrés au cours de l'acquisition. Ma thèse concerne la calibration intrinsèque d'un C-arm à partir de la détection de la projection du collimateur de la source dans les radiographies.Nous avons développé une méthode de détection de la projection des bords linéaires du collimateur. Elle surpasse les méthodes classiques comme le filtre de Canny sur données simulées ou réelles. La précision que nous obtenons sur l'angle et la position (phi,s) des droites est de l'ordre de: phi{RMS}=+/- 0.0045 degrees et s{RMS}=+/- 1.67 pixels. Nous avons évalué nos méthodes et les avons comparés à des méthodes classiques de calibration dans le cadre de la reconstruction 3D. / Mobile isocentric x-ray C-arm systems are an imaging tool used during a variety of interventional and image guided procedures. Three-dimensional images can be produced from multiple projection images of a patient or object as the C-arm rotates around the isocenter provided the C-arm geometry is known. Due to gravity affects and mechanical instabilities the C-arm source and detector geometry undergo significant non-ideal and possibly non reproducible deformation which requires a process of geometric calibration. This research investigates the use of the projection of the slightly closed x-ray tube collimator edges in the image field of view to provide the online intrinsic calibration of C-arm systems.A method of thick straight edge detection has been developed which outperforms the commonly used Canny filter edge detection technique in both simulation and real data investigations. This edge detection technique has exhibited excellent precision in detection of the edge angles and positions, (phi,s), in the presence of simulated C-arm deformation and image noise: phi{RMS} = +/- 0.0045 degrees and s{RMS} = +/- 1.67 pixels. Following this, the C-arm intrinsic calibration, by means of accurate edge detection, has been evaluated in the framework of 3D image reconstruction.
43

Alterações de difusão e perfusão cerebral por RM em angioplastia carotídea com \"stent\" sob proteção cerebral por filtros / Changes in diffusion and perfusion weighted magnetic resonance imaging in carotid angioplasty with stenting under cerebral protection by filters

Antenor Tavares de Sá Júnior 09 October 2009 (has links)
INTRODUÇÃO: A angioplastia carotídea com stent (ACS) sob proteção cerebral é opção terapêutica em pacientes com estenose carotídea. Existe o risco de embolia apesar da utilização do filtro e as modificações na perfusão cerebral após tratamento da estenose carotídea não são claras. O propósito deste estudo é avaliar, após ACS sob proteção cerebral por filtros, modificações nas seqüências de RM de difusão (DWI) e perfusão (PWI), correlacionando-as com os aspectos técnicos da ACS, com as características da estenose e com dados demográficos dos pacientes. MÉTODO: Trinta e seis pacientes portadores de estenose carotídea com idade média de 72,08 anos foram submetidos a exame de RM um dia antes e até 72 horas após a ACS com filtro de proteção. Todos os pacientes eram assintomáticos após a ACS. Áreas de restrição na DWI após a ACS foram correlacionadas com aspectos demográficos, com aspectos da técnica de angioplastia e com a presença de infartos prévios por RM. Os parâmetros CBV volume sanguíneo cerebral, MTT tempo de trânsito médio e TTP tempo para o pico são empregados para análise por PWI. RESULTADOS: Na DWI, 18 de 36 (50,00%) pacientes apresentaram novos focos (NF) de restrição na DWI após ACS. Todos os NF foram clinicamente silenciosos (100%). Estes NF eram localizados em território cerebral nutrido pela artéria carótida submetida à ACS em 77,19% e menores que 10 mm em 91,53%. Os NF em território cerebral não irrigado pela artéria carótida submetida à angioplastia correspondiam a 22,81% destes. A presença de infartos cerebrais prévios na RM foi o único fator com influência no aparecimento de NF (p=0,037). Fatores demográficos e aspectos relacionados com a técnica de angioplastia não tiveram importância na gênese dos NF. Na PWI foi observada melhora nos parâmetros temporais TTP (p<0,001) e MTT (p=0,019) quando comparados de forma normalizada em relação ao território contralateral. CONCLUSÃO: Os novos focos de restrição na DWI após ACS (NF) foram mais comuns no território ipsilateral (77,19%), no entanto houve NF no território contralateral à ACS (22,81%), possivelmente, associados ao cateterismo diagnóstico. Os NF, na sua maioria, são de pequeno diâmetro (<10 mm em 91,53%). Melhora precoce na PWI, observada nos dados normalizados, foi demonstrada nos parâmetros temporais (TTP e MTT). / INTRODUCTION: Carotid angioplasty with stent (CAS) under cerebral protection is a therapeutic option in patients with carotid stenosis. There is a risk of embolism even with a filter, and changes in cerebral perfusion after treatment are not clearly understood. The purpose of this study was to evaluate changes in diffusion- (DWI) and perfusion- (PWI) weighted magnetic resonance imaging (MRI) sequences correlating them with the technical aspects of CAS, stenosis characteristics and patient demographic data. METHODS: Thirty-six carotid stenosis patients with an mean age of 72.08 years were submitted to MRI exam one day before and up to 72 hours after CAS with filter protection. All patients were asymptomatic after CAS. Areas of restriction on DWI were correlated to demographic aspects, technique of angioplasty as well the presence of previous stroke by MRI. The parameters, CBV - cerebral blood volume; MTT - mean transit time, and TTP- time to peak, are used for PWI analysis. RESULTS: Eighteen of the 36 patients (50.00%) presented new focus (NF) of restriction by DWI after CAS. All new focus were clinically silent. The NF were located in the cerebral area fed by the carotid artery submitted to CAS in 77.19% and smaller than 10mm in 91.53%. NF in cerebral area not irrigated by carotid artery submitted by angioplasty correspond to 22,81 %. The presence of previous ischemic lesion on MRI was the only factor which influenced the appearance of NF (p=0.037). Demographic factors and aspects related to angioplasty technique had no importance on NF genesis. Improvement in PWI timing parameters - TTP (p<0.001) and MTT (p=0.019) were observed in relation to the contralateral territory (normalized data). CONCLUSION: The restriction NF in the DWI after CAS are more common in the ipsilateral territory (77.19%), however there were some NF in the contralateral territory to the CAS (22.81%), possibly associated with diagnostic catheterization. Most of the NF were small in diameter (<10mm in 91.53%). Short-term improvement in PWI were demonstrated by normalized timing parameters (TTP and MTT).
44

Tratamento endovascular das malformações arteriovenosas raquimedulares: resultados clínicos e angiográficos / Endovascular treatment for spinal cord arteriovenous malformations : clinical and angiographic results

Mario Luiz Marques Conti 30 August 2005 (has links)
Trinta e cinco pacientes com malformações arteriovenosas raquimedulares (MAVR) foram tratados por via endovascular. Foram analisados os tipos de MAVR, bem como os aspectos clínicos e angiográficos pré e pós-tratamento endovascular. As MAVR mais freqüentes foram as fístulas arteriovenosas durais (FAD), com 17 pacientes, seguidas das malformações arteriovenosas intramedulares (MAI), fístulas arteriovenosas perimedulares (FAVP) e malformações arteriovenosas metaméricas (MAVM). A avaliação do resultado do tratamento foi dividida em sucesso técnico e clínico, sendo que o primeiro foi subdividido em sucesso técnico do procedimento e do tratamento. O sucesso técnico do procedimento foi caracterizado como oclusão total da MAVR ao final de um procedimento endovascular. O sucesso técnico do tratamento foi caracterizado pela oclusão definitiva da MAVR, independentemente do número de procedimentos. A recidiva foi definida como o reaparecimento da MAVR, identificada na angiografia durante o seguimento dos pacientes, independentemente do quadro clínico apresentado. A recidiva implicava em insucesso do procedimento, mas não necessariamente do tratamento. O sucesso clínico do tratamento foi considerado como a melhora parcial ou total dos sintomas após um período mínimo de acompanhamento de 6 meses. Nas FAD, houve predomínio do sexo masculino e da faixa etária acima dos 36 anos. O tratamento endovascular das FAD mostrou sucesso do procedimento na maioria dos casos, porém com recidiva da lesão em 56,7% dos mesmos. Quando usadas partículas, observou-se recidiva em 73,3% dos procedimentos, porém com sucesso do tratamento em 66,7 dos pacientes. Quando utilizado o adesivo tissular (\"cola\"), houve recidiva em 11,1% dos procedimentos e sucesso do tratamento em 88,9% dos pacientes. A melhora clínica foi obtida em 64,7% dos pacientes. Dos 10 pacientes tratados com MAI, a faixa etária mais freqüente foi dos 19 aos 35 anos de idade e predomínio do sexo masculino. O tratamento endovascular das MAI mostrou sucesso do procedimento em 53,3% e recidiva da lesão em 6,7% dos pacientes. O sucesso do procedimento também foi superior quando usada cola, atingindo 63,6% dos procedimentos e apenas 25,0% com partículas. O sucesso do tratamento foi de 80,0% e a melhora clínica foi observada em 40,0% dos pacientes. Somente 1 paciente com MAVM foi tratado. O tratamento objetivou a embolização parcial da lesão para alívio dos sintomas, resultado que foi obtido com sucesso. Nas FAVP houve predomínio do sexo masculino e a faixa etária mais acometida foi dos 19 aos 35 anos. O tratamento endovascular das FAVP mostrou sucesso do procedimento em 75,0% dos pacientes e ausência de recidiva. O sucesso do tratamento foi de 85,7%, com melhora clínica em todos os pacientes. O nosso estudo mostrou que as MAVR podem ser tratadas de maneira eficiente e segura através da embolização. O seguimento dos pacientes tratados com cola mostrou menor índice de recidiva do que aqueles tratados com partículas. Após a embolização, houve melhora significativa no padrão da marcha nos pacientes com FAD e MAI / Endovascular treatment was used in 35 patients with spinal cord arteriovenous malformations (SCAVM). SCAVM types, along with clinical and angiographic features of pre-op and post-op endovascular treatments were analyzed. Seventeen patients had dural arteriovenous fístulas (DAVF), being this type the most frequent SCAVM, followed by intramedullary arteriovenous malformations (IAVM), perimedullary arteriovenous fístulas (PAVF) and metameric arteriovenous malformations (MAVM). Evaluation of treatment results was divided into technical and clinical success, being the first subdivided into technical success of the procedure and treatment. The procedural\'s technical success was characterized by total SCAVM occlusion at the end of an endovascular procedure. Technical success of the treatment was characterized by definitive occlusion of the SCAVM, independent of the number of procedures. Recurrence was defined as reappearance of SCAVM, identified on angiograms during patient follow up, independent of the observed clinical situation. Recurrence implied in an unsuccessful procedure but not necessarily in treatment failure. Treatment\'s clinical success was considered partial or total symptom improvement after a minimum 6 month period follow up. Male and age over 36 years was preponderate in DAVF. Endovascular treatment in DAVF had procedural success in most cases, but with lesion recurrence in 56,7% of these patients. When particulate embolic agents were used, recurrence occurred in 73,3% of the procedures but with treatment success in 66,7% of these patients. When liquid tissue adhesive was used, there was 11,1% of recurrence and 88,9% in treatment success in these patients. Clinical improvement occurred in 64,7% of these patients. Male predominance and age between 19 to 35 years was more frequent in the 10 treated patients with IAVM. IAVM endovascular treatment was a procedural success in 53,3% and lesion recurrence in 6,7% of these patients. Procedural success was also superior when liquid tissue adhesive was used, up to 63,6% of these procedures and, only 25,0% with particulate embolic agents. Treatment success occurred in 80,0% and clinical improvement seen in 40,0% of these patients. Only 1 patient with MAVM was treated. Aim in treatment was partial lesion embolization to mitigate symptoms, which was successfully achieved. Male predominance and age between 19 to 35 years occurred in PAVF. PAVF endovascular treatment had procedural success in 75,0% and no recurrences in these patients. Treatment success occurred in 85,7% and clinical improvement in all patients. This study demonstrates that SCAVM can be treated efficiently and safely with endovascular embolization. Patient follow up revealed fewer recurrences in those treated with liquid tissue adhesive than in those with particulate embolic agents. After DAVF and IAVM embolization, patients had significant improvement in their gait

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