Viewpoint-Based Ambient Occlusion

We've developed a new ambient occlusion technique based on an information-theoretic framework. Essentially, our method computes a weighted visibility from each object polygon to all viewpoints; we then use these visibility values to obtain the information associated with each polygon. So, just as a viewpoint has information about the model's polygons, the polygons gather information on the viewpoints. We therefore have two measures associated with an information channel defined by the set of viewpoints as input and the object's polygons as output, or vice versa. From this polygonal information, we obtain an occlusion map that serves as a classic ambient occlusion technique. Our approach also offers additional applications, including an importance-based viewpoint-selection guide, and a means of enhancing object features and producing nonphotorealistic object visualizations

Estudio piloto de la relación entre el aumento de la velocidad de onda del pulso en arteria carótida común medida por resonancia magnética y los factores de riesgo vasculares clásicos en sujetos con sospecha de lesión cerebrovascular isquémica

Arterial stiffness assessed by carotid-femoral pulse wave velocity (cfPWV) measurement is now well accepted as an independent predictor of vascular mortality and morbidity. However, the value of cfPWV has been considered to be limited for risk classification in patients with several vascular risk factors. Magnetic resonance (MR) allows measurement of PWV between two points, though to date mainly used to study the aorta. To assess the common carotid artery pulse wave velocity by magnetic resonance, determine their association with classical vascular risk factors and ischemic brain injury burden in patients with suspected ischemic cerebrovascular disease

Cessació de l'hàbit tabàquic en pacients afectats de malaltia vascular cerebral aguda

S'han estudiat 1003 pacients amb el diagnòstic de Malaltia Vascular Cerebral (MVC) aguda ingressats a la unitat de neurologia de l'Hospital Josep Trueta de Girona en el període de gener de 2005 a juliol de 2007. S'ha realitzat un estudi de cohorts prospectiu d'un any en 110 pacients que eren fumadors en el moment de l'ictus. Un elevat percentatge dels pacients afectats de MVC aguda presenten factors de risc vascular que es poden evitar com el consum de tabac o d'alcohol, i factors de risc vascular que cal controlar com la hipertensió, la dislipèmia, la diabetis o la cardiopatia. Només 4 de cada 10 pacients fumadors diagnosticats d'ictus havien abandonat l'hàbit un any després de presentar la MVC aguda. Les variables que millor prediuen la cessació tabàquica en aquests pacients són la localització de la lesió a l'ínsula cerebral i la intenció de deixar de fumar prèvia a l'ictus.