ABSTRACT
Mimicking angiogenetic processes in vascular territories acquires importance in the analysis of the multi-scale circulatory cascade and the coupling between blood flow and cell function. The present work extends, in several aspects, the Constrained Constructive Optimisation (CCO) algorithm to tackle complex automatic vascularisation tasks. The main extensions are based on the integration of adaptive optimisation criteria and multi-staged space-filling strategies which enhance the modelling capabilities of CCO for specific vascular architectures. Moreover, this vascular outgrowth can be performed either from scratch or from an existing network of vessels. Hence, the vascular territory is defined as a partition of vascular, avascular and carriage domains (the last one contains vessels but not terminals) allowing one to model complex vascular domains. In turn, the multi-staged space-filling approach allows one to delineate a sequence of biologically-inspired stages during the vascularisation process by exploiting different constraints, optimisation strategies and domain partitions stage by stage, improving the consistency with the architectural hierarchy observed in anatomical structures. With these features, the aDaptive CCO (DCCO) algorithm proposed here aims at improving the modelled network anatomy. The capabilities of the DCCO algorithm are assessed with a number of anatomically realistic scenarios.
Subject(s)
Algorithms , Arteries/physiology , Hemodynamics/physiology , Models, Cardiovascular , Computer Simulation , Humans , Models, AnatomicABSTRACT
Introdução: A reconstrução tridimensional coronária com a combinação do ultrassom intracoronário e da angiografia apresenta vantagens em relação à angiotomografia de coronárias. Objetivamos apresentara fase piloto de validação de um novo modelo de reconstrução tridimensional de artérias coronárias. Métodos: Foram utilizados exames de angiografia e ultrassom intracoronário já realizados por indicação clínica em indivíduos com suspeita ou diagnóstico de doença arterial coronária estável. O processamento das imagens, a segmentação e a reconstrução tridimensional foram realizados seguindo metodologia específica. Para fins de caracterização geométrica, foram obtidas as linhas de centro tridimensionais. Resultados: Foram reconstruídos três vasos, sendo duas artérias descendentes anteriores e uma artéria circunflexa. O volume da luz do vaso e a carga de placa global puderam ser visualizados com facilidade com a reconstrução tridimensional. A caracterização geométrica revelou aumento dos valores absolutos do comprimento, tortuosidade, curvatura e torsão, caracterizando uma maior complexidade da linha de centro da luz doente, em relação à linha de centro da membrana elástica externa. Conclusões: Essa nova metodologia, que integrou angiografia convencional e ultrassom intracoronário, aumentou a praticidade das reconstruções, com ganho em acurácia volumétrica do vaso e visualização global de aspectos-chave da doença aterosclerótica, como remodelamento e distribuição da placa.
Background: Coronary three-dimensional reconstruction with the combination of intravascular ultrasound and angiography offers advantages over computed tomography angiography of coronary arteries. The authors aimed to present the pilot phase of the validation of a new model of three-dimensional reconstruction of coronary arteries. Methods: This study used angiography and intravascular ultrasound examinations already performed by clinical indication in individuals with known or suspected stable coronary artery disease. Image processing, segmentation, and three-dimensional reconstruction were conducted following specific methodology. For geometrical characterization purposes, tridimensional center lines were obtained. Results: Three vessels were reconstructed: two left anterior descending arteries and one left circumflex artery. The vessel lumen volume and the overall plaque burden could be easily viewed with threedimensional reconstruction. The geometric characterization revealed increased absolute values of length, tortuosity, curvature, and torsion, featuring a greater complexity of the center line of the diseased lumen relative to the center line of the external elastic membrane. Conclusions: This new methodology, which integrates conventional angiography and intravascular ultrasound, has increased the practicality of the reconstructions, with a gain in volumetric accuracy of the vessel and overall visualization of key aspects of atherosclerotic disease, such as plaque remodeling and distribution.
