Doctorant sous la direction de D. LESSELIER

Titre de la thèse: Early Breast Abnormalities Detection via Electromagnetic and Ultrasonic Joint Modalities
Résumé de la thèse: The PhD is conducted in close cooperation between two laboratories within the Paris-Saclay University, SATIE or Systems and Applications of Information and Energy Technologies, directed by Thomas Rodet, and L2S or Laboratory of Signals and Systems, and its Signals and Statistics Division, directed by Dominique LESSELIER. In the context of early detection of breast cancer and generally speaking of abnormalities by non-invasive/non-ionizing methods intended to work on an uncompressed breast, we wish to design/study algorithms of fusion/inversion of joint data. Electromagnetic and ultrasound modalities are easily deployed indeed in similar conditions (so-called free breast in coupling medium), and are complementary in terms of information, meaning local resolution and sensitivity to contrasts, and more generally about constituent media and distributions thereof. We measure in both modalities at the same time since breasts are soft organs that deform in non-rigid manner between different examinations. Then , an information fusion methodology must be used which is coherent with an inverse problem solution method, and a Bayesian methodology will well fit therein. To avoid the limitation of resolution in microwave imaging caused by the relatively small number of illuminations that can be introduced because of the complexity of the direct model, we will use an adaptive grid of quadtree type, so that in particular homogeneous zones are modeled by a small number of voxels focusing onto the boundaries of objects. The project will lead to the development of a new multi-modality data fusion algorithm (microwave & ultrasound). The performance of the approach will be evaluated on realistic numerical simulation data. The work is expected to render possible to get real gains in terms of resolution and contrast, noticing also that in the case of tumors of small sizes the bad resolution indeed reduces the contrast due to the partial volume effect.

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