L’angioplastie coronaire primaire percutanée est le traitement de choix du syndrome coronarien aigu avec sus-décalage du segment ST (STEMI) avec une efficacité prouvée pour reperméabiliser l’artère coupable. Un flux TIMI (thrombolysis in myocardial infarction) 3 est généralement restauré dans plus de 90% des patients.Cependant, l'embolisation distale d'un thrombus angiographiquement visible (EDAV) a été identifiée comme l'une des complications majeures de l’angioplastie primaire dans le STEMI, car elle limite l'efficacité de la reperfusion myocardique et conduit à un plus mauvais pronostic.Notre objectif était de déterminer la fréquence des EDAV au cours de l’angioplastie primaire pour STEMI et d’en identifier les facteurs déterminants.Nous avons évalué 779 patients dont 560 hommes (71,9 %) victimes de STEMI et traités par angioplastie primaire. La thromboaspiration était réalisée dans plus de la moitié des cas (53%).L’âge moyen des patients était de 64,03 ± 14,67 ans. Les EDAV étaient fréquentes, de l’ordre de 15%.Les facteurs indépendants liés à la survenue d’EDAV étaient des facteurs cliniques à savoir l’âge > 60 ans, le sexe féminin, la thrombectomie, et la coronaire droite coupable. Aucun critère de la lésion coupable n’a été identifié comme prédicteur d’EDAV.Chez les patients thrombectomisés, les EDAV survenaient dans 17,41% des cas. Les facteurs prédictifs indépendants de ces embolies distales étaient l’atteinte de la coronaire droite et un diamètre de référence de l’artère coupable ˃ 3 mm.Dans la mesure où le succès de la thrombectomie restaure le flux coronaire, nous nous sommes intéressés à la relation entre le succès de cette technique et la survenue des EDAV. Ce travail a montré que la survenue des EDAV n’était liée ni au score syntax, ni au succès de la thrombectomie, mais à deux critères angiographiques à savoir l’atteinte de la coronaire droite et un diamètre de l’artère coupable supérieur à 3 mm.Ces données suggèrent que la coronaire droite est l’élément central de survenue des EDAV. Il s’agit d’une artère double coudée et habituellement de gros calibre. Il semble de ce fait nécessaire de mener des ’études spécifiques sur la coronaire droite. / Percutaneous primary coronary angioplasty is the cornerstone for acute coronary syndrome with ST segment elevation (STEMI) treatment with proven efficacy to restore flow in culprit coronary artery. A TIMI (thrombolysis in myocardial infarction) 3 flow is generally restored in more than 90 % of patients. However, distal embolization of an angiographically visible thrombus (EDAV) has been identified as one of the major complications of primary angioplasty in STEMI because it limits the effectiveness of myocardial reperfusion and leads to a worse prognosis.Our objective was to determine the frequency of EDAVs during primary angioplasty for STEMI and to identify the determining factors.We evaluated 779 patients, including 560 men (71.9%) suffering from STEMI and treated with primary angioplasty. Thromboaspiration was performed in more than half of the cases (53%). The mean age of the patients was 64.03 ± 14.67 years. EDAVs were frequent (15%). Independent factors related to the occurrence of EDAV were clinical factors such as age > 60 years, female sex, thrombectomy, and culprit right coronary. No criterion from culprit lesion was identified as predictors of EDAV.In thrombectomized patients, EDAVs occurred in 17.41 % of cases. Independent predictor factors of these distal embolisms were right coronary artery target and culprit artery diameter ˃ 3 mm.Since the success of thrombectomy restores coronary flow, we are interested in the relationship between the success of this technique and the occurrence of EDAV. This work showed that the occurrence of EDAV was not related to the syntactic score nor to the success of the thrombectomy but to two angiographic criteria, namely right coronary artery disease and culprit artery diameter greater than 3 mm.These data suggest that right coronary artery is the central component of EDAV occurrence. It is a double bent artery and usually of large caliber. It therefore seems necessary to carry out specific studies on the right coronary artery.

No intuito de transformar sistemas de angiografia convencionais em sistemas de subtração digital com angiografia foram implementados três métodos de subtração digital: subtração digital por complemento de um, subtração por comparação 1 e subtração digital por comparação 2 e dois métodos de processamento: \"threshold\" e equalização para aplicação em sistemas angiográficos (DSA). O estudo destes métodos foi realizado com a simulação em sistemas gráficos a partir do qual foram avaliados o realce das pequenas estruturas vasculares, a influência do ruído e a velocidade de operação na subtração das imagens. Os algoritmos desenvolvidos em linguagem Pascal, utilizando Borland Delphi 2.0 (32 bits) foram testados com imagens obtidas no Hospital das Clínicas de Ribeirão Preto e os resultados foram comparados por análise visual. / In the intention of transforming systems of conventional angiography in systems of digital subtraction with angiography three methods of digital subtraction were implemented, digital subtraction for complement of a, subtraction for comparison 1 and digital subtraction for comparison 2 two processing methods: threshold and equalize for application in systems angiographycs (DSA). The study of these methods was accomplished with the simulation in graphic systems statting from which were appraised it enhances it of the small vascular structures, the influence of the noise and the operation speed in the subtraction of the images. The algorithms developed in linguage Pascal, using Borland Delphi 2.0 (32 bits) they were tested with images obtained in the Hospital of the Clinics in Ribeirão Preto and the results were compared by visual analysis.

No description available.

No description available.

No description available.

Thesis (M. S.)--Biomedical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Tannenbaum, Allen; Committee Member: Skrinjar, Oskar; Committee Member: Yezzi, Anthony. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (doctoral)--Katholieke Universiteit te Nijmegen.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 117-124).

The diagnosis and treatment of cerebrovascular disease, such as stroke and vascular lesions in the brain, requires knowledge of the status of brain tissue and cerebral arteries. Perfusion imaging and angiography offer information on blood flow to the tissue and through the brain-feeding arteries. A variety of imaging modalities exist to assess brain haemodynamics, including measures of cerebral blood flow and other parameters, however many of these are invasive and/or involve the use of contrast agents toxic to certain patient populations. One non-invasive magnetic resonance imaging alternative for perfusion imaging and angiography, which also provides vessel specific blood flow information, is vessel-encoded pseudocontinuous arterial spin labelling (VEPCASL). VEPCASL uses the blood as an endogenous tracer and can magnetically label the blood from different arteries of interest. The combination of VEPCASL with different imaging strategies can provide a map of the vascular perfusion territories in the brain, or dynamic information on blood flow through the cerebral arteries. The work in this thesis seeks to optimise and develop the encoding process of VEPCASL and accompanying angiographic readouts. Firstly, a rapid and automated method for calculating a minimal number of signal-to-noise ratio (SNR) efficient encodings, for any number and arrangement of vessels, was developed. Its use resulted in improved SNR in perfusion territories fed by more complicated vessel arrangements in the labelling plane. The labelling efficiency of VEPCASL, and its non-vessel-selective equivalent, PCASL, is affected by the presence of magnetic field inhomogeneities in the labelling plane. Consequently, a correction for phase offsets was introduced into the calculation of the optimised encodings. These encodings enabled the recovery of SNR in perfusion territories for PCASL and VEPCASL when phase offsets were present at the labelled arteries. As current VEPCASL angiography methods are relatively slow to acquire, an accelerated readout was developed to acquire two-dimensional vessel-selective dynamic angiograms in approximately one minute. A radial k-space trajectory was found to offer the best vessel definition and SNR. Three-dimensional (3D) angiograms provide the most detailed view of the cerebral vasculature for use in diagnosis and treatment of cerebrovascular disease. A 3D radial readout was optimised to acquire vessel-selective dynamic angiograms. These angiograms offer information on the structure of the vascular tree and how it is fed by the major arteries in the neck. The techniques developed here aim to increase the clinical viability and applicability of VEPCASL perfusion imaging and angiography. It is hoped that the techniques herein could be used in patient populations to add to and improve the diagnostic information available.

No intuito de transformar sistemas de angiografia convencionais em sistemas de subtração digital com angiografia foram implementados três métodos de subtração digital: subtração digital por complemento de um, subtração por comparação 1 e subtração digital por comparação 2 e dois métodos de processamento: \"threshold\" e equalização para aplicação em sistemas angiográficos (DSA). O estudo destes métodos foi realizado com a simulação em sistemas gráficos a partir do qual foram avaliados o realce das pequenas estruturas vasculares, a influência do ruído e a velocidade de operação na subtração das imagens. Os algoritmos desenvolvidos em linguagem Pascal, utilizando Borland Delphi 2.0 (32 bits) foram testados com imagens obtidas no Hospital das Clínicas de Ribeirão Preto e os resultados foram comparados por análise visual. / In the intention of transforming systems of conventional angiography in systems of digital subtraction with angiography three methods of digital subtraction were implemented, digital subtraction for complement of a, subtraction for comparison 1 and digital subtraction for comparison 2 two processing methods: threshold and equalize for application in systems angiographycs (DSA). The study of these methods was accomplished with the simulation in graphic systems statting from which were appraised it enhances it of the small vascular structures, the influence of the noise and the operation speed in the subtraction of the images. The algorithms developed in linguage Pascal, using Borland Delphi 2.0 (32 bits) they were tested with images obtained in the Hospital of the Clinics in Ribeirão Preto and the results were compared by visual analysis.