Metaheuristics for Specialization of a Segmentation Algorithm for Ultrasound Images

An unseeded segmentation system applied to ultrasound (US) imaging is presented, based on a compact segmentation algorithm. Its basic behavior is adapted by a region selection algorithm controlled by a region classification function, which scores the relevance of regions generated from the previous segmentation step. This approach results in a completely unseeded system. Its behavior, represented by a fuzzy rule system, is specialized for the present clinical application by means of two different bioinspired approaches that minimize the segmentation error against a human expert asked to fulfill the same task. The first one is based on a real-valued genetic algorithm, whereas the second is based on an ant colony stigmergic algorithm. The two methodologies are tested and benchmarked on four data sets: 1) breast US images for carcinoma screening; 2) obs/gyn US for ovarian follicles assessment; and 3) two applications in anesthesiology US during brachial anesthesia. Results show that the proposed bioinspired approaches are well suited for these complex tasks and can be used as a straightforward methodology to adapt an image segmentation algorithm to fulfill recognition tasks. The system could be adapted to any application in US imaging that requires identification of anatomical districts, morphological structures, and any other region of interest related to the clinical practice.