A mi familia y, especialmente, a mi mitad.
RESUMENLas enfermedades cardiovasculares son una de las principales causas de mortalidad del mundo. Tras la mayoría de muertes por enfermedad cardiovascular la principal responsable es la arteriosclerosis. La arteriosclerosis consiste en un engrosamiento progresivo del tejido vascular que reduce la elasticidad de los vasos sanguíneos afectados y puede llegar incluso a obstruirlos. Esta enfermedad se desarrolla en la infancia y adolescencia, pudiendo llegar a pasar desapercibida toda la vida o bien actuando como detonador de otras afecciones más serias, como infartos, derrames cerebrales o isquemias. Por todo ello, la detección precoz de la arteriosclerosis resulta de vital importancia.En la actualidad, se viene usando el grosor íntima-media o IMT de la arteria carótida común como indicador fiable y precoz de la arteriosclerosis. Este indicador mide el grosor entre las capas íntima y media de la carótida común en cortes longitudinales de la arteria en imágenes ecográficas. El uso de los ultrasonidos para extraer esta medida, además de barato, resulta no invasivo para el paciente. Sin embargo, esta modalidad de imagen no está exenta de desventajas, como el elevado nivel de ruido que presenta o la alta dependencia del operador.The results after the active contour algorithm are automatically validated to avoid the inclusion of wrong segmented sections in the final measurements. These wrong sections are due to, mainly, the presence of gaps in the image which do not provide any information about the external forces image. This additional validation stage is based on two strategies, statistical and intensity-based. By combining both strategies, we avoid the inclusion of sections with big gaps or in which the measurements are unlikely in anatomical terms.An exhaustive result characterization has been accomplished. Four different metrics have been used to evaluate the distances between contours. Considering the average of four manual measurements as ground truth, automatic segmentation has been compared to manual segmentation. The four considered metrics have been used to evaluate the IMT, the lumen diameter and the distances between manual and automatic delineations. En each case, Pearson's correlation coefficient, error distribution and Bland-Altman's plots have been calculated.
VIIIThe ultrasound image dataset has been obtained with a single ultrasound scanner with two different probes, each of them working at different frequency range. Unlike other methods, in which the spatial resolution is not variable, the scanner configuration is flexible for the radiologist, at his/her own discretion. Thus, spatial resolution may vary from one image to another, ranging from 0.029 mm/pixel to 0.082 mm/pixel in our database.IMT has been automatically measured in all 58 images in our database. The images correspond to 35 patients, none of them previously diagnosed with atherosclerosis. The mean IMT error is comparable or even less than the error in other automatic methods. Besides, the dist...