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Com os avancos tecnologicos das ultimas decadas, a ecocardiografia surgiu como uma alternativa de diagnostico por imagem de relativo baixo custo, que nao faz uso de energia ionizante ou radioativa. Recentemente, o advento dos agentes de contraste por microbolhas e dos transdutores matriciais tornou possivel a visualizacao tridimensional da anatomia das arterias coronarias. Neste projeto, e proposta a avaliacao de metodos de segmentacao capazes de visibilizar as arterias coronarias epicardicas em Imagens de ecocardiografias tridimensionais com contraste de microbolhas. Esse e o primeiro passo para o desenvolvimento de ferramentas computacionais eficazes e eficientes na assistencia nao invasiva ao acompanhamento do quadro clinico de pacientes, do diagnostico ao pos-operatorio. Propoe-se, uma metodologia que facilite o acesso as coronarias a partir de imagens de ecocardiografia tridimensionais com aplicacao de contraste por microbolhas. Dentre as metodologias estudadas, as tecnicas baseadas na teoria Fuzzy Connectedness (FC) foram identificadas como as mais promissoras. Estudou-se, portanto, seis abordagens baseadas nessa teoria, tres delas sao descritas na literatura (Generalized FC GFC; Relative FC RFC; Dynamic Weighted FC DyWFC) e tres proposicoes originais (Area of Search FC ASFC; Ultrasound-k FC USFC; Guided FC GuFC). Para avaliar a acuracia desses algoritmos, confeccionou-se um conjunto de imagens simuladas, composto por 360 imagens, e selecionou-se um conjunto de imagens de exames reais, composto de 10 imagens reais de pacientes com quadro de Cardiomiopatia Hipertropica. Para as imagens simuladas, os metodos da literatura alcancaram acuracia de 85,5% para GFC, 89,5% para RFC e 92,0% para DyWFC. Enquanto isso, os metodos propostos alcancaram acuracia de 88,9% para ASFC, 91,7 % para USkFC e 95,2% para GuFC... With the technological advances of recent decades, echocardiography has emerged as a relatively low cost imaging diagnostic alternative, that does not use ionizing or radioactive energy. Lately, the advent of micro bubble-based contrast agents and array transducers turned possible the visualization of three-dimensional coronary arteries anatomy. The present project proposes to evaluate segmentation methods able to deal with the visualization of the epicardial coronary arteries in microbubble-based three-dimensional echocardiography images. This is the first step towards the development of effective and efficient computational tools for diagnosis and prognosis assistance of cardiac pacient. We propose a methodology to facilitate the access to epicardial coronary arteries in tridimensional echocardiographic images. Among the studied approaches, Fuzzy Connectedness based segmentation methods were identified as being the most promising. We studied six approaches based on this theory, three of them are described in the literature (Generalized FC GFC; Relative FC RFC; Dynamic Weighted FC DyWFC) and three original contributions (Area of Search FC ASFC; Ultrasound-k FC USFC; Guided FC GuFC). To evaluate the accuracy of these algorithms, a set composed of 360 simulated images were created. We also selected a set of 10 real images, composed of hypertrophic cardiomyopathy patients. For simulated images set, the methods of literature achieved accuracy of 85.5% for GFC, 89,5% for RFC and 92,0% for DyWFC, meanwhile, the proposed method achieved accuracy of 88.9% for ASFC, 91,7 % for USkFC and 95,2% for GuFC. Using the real images set, the methods converged to good results for clinical purposes. These results demonstrate that the proposed method GuFC has shown a better performance than the others, becoming a candidate to the segmentation step in a computational tool for coronary arteries visualization in the future...

Visibilização de artérias coronárias epicárdicas em imagens ecocardiográficas tridimensionais com contraste de microbolhas