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Work period: For 6 months, starting anytime between September 2011 to january 2012
Necessary skills: Image and video processing, modelling, mathematics, medical physics, Matlab programming, capacity of fast integration in a multidisciplinary context, potential for publication.
Work environnement: Creatis is a biomedical imaging research laboratory, with about 200 persons, whose main areas of excellence and international influence are linked to two fundamental problems, namely: Identification of major health issues that can be addressed by imaging and identification of theoretical barriers in biomedical imaging related to signal and image processing, modelling and numerical simulation. Creatis meets these challenges through a multidisciplinary approach, based on a matrix organisation which stimulates interaction between six research teams working in information and communication science and technology, engineering sciences and life sciences. This project is supported by 3 teams: Imaging of the Heart-Vessels-Lungs (team 1), Ultrasound Imaging (team 3) and MRI and Optics: Methods and Systems (team 5).
Project context: The research on the cardiovascular diseases detection represents a major public challenge in health in the whole of industrial nations. These diseases are indeed the main cause of death in these countries. A set of medical imaging modalities exits allowing to improve the diagnoses and the therapeutic choices for the follow-up of the patients suffering from cardiovascular diseases (angiography, tomography, ultrasonography, MRI). The analysis of the movement in the images yields the information about the dynamics of the cardiovascular structures. That is why numerous methods of motion estimation were developed the last decade. Several teams of Creatis work on this topic. Each team possesses appropriate skills on the medical parts, the acquisition and the image processing of ultrasound and MRI sequences. The current images already allow a quantification of the dynamics of the vascular wall or the myocardium but, this quantification remains often global.
Objective: We suggest defining new phase images carrier of the local orientations of the motion and estimating these motions to extract from it parametric maps (deformations, trajectories). The scientific challenge is the investigation of a new approach in medical imaging based on Clifford's algebra. This approach will allow to define dynamic multiquaternion sequences of the spatial phase for the estimation of the cardiovascular motion. The medical interest is the precise and local quantification of the dynamics of the vascular wall and the cardiac wall by the association of two imaging modalities (ultrasonography + MRI).
Method: The main idea is based on the multiquaternion Clifford algebra for video processing. In this context, we propose a new description of the analytical signal 2D+t and its spatial phases. This new formalism is going to lead us to develop a subpixelic method for estimating and tracking non rigid motion adapted to the new sequences of spatial phase. To quantify the estimated motions, maps of deformations and trajectories of material points of the vascular wall and of the cardiac muscle will be extracted from these images of phase. The three main steps of the project are thus: the multiquaternion analytical signal and the phase video, the phase based motion estimation and the extraction of trajectories, the application in cardiovascular data with two image modalities.
People involved in the project: Patrick Clarysse, Creatis Dr Pierre Croisille, Creatis, HCL Philippe Delachartre, Creatis Patrick Girard, Creatis Dr André Sérusclat, HCL
Application: Please send a CV including a list of publications, a letter in support of application, and 2 reference letters to: Philippe Delachartre – delachartre@creatis.insa-lyon.fr
References:
[Aja-Fernandez-09] Santiago Aja-Fernandez et al., Tensors in image Processing and Computer Vision, Advances in Pattern Recognition, Springer, 2009.
[Arts-10] T. Arts, F.W. Prinzen, T. Delhaas, J. Milles, P. Clarysse, Mapping displacement and deformation of the heart with local sine wave modelling, IEEE Trans. on Medical Imaging, vol. 29, n° 5, pp. 1114-1123, may 2010.
[Basarab-09] A. Basarab, P. Gueth, H. Liebgott, and P. Delachartre. Phase-based block matching applied to motion estimation with unconventional beamforming strategies. IEEE Trans Ultrason Ferroelectr Freq Control, 56(5):945-957, 2009.
[Croisille-09] P. Croisille. Cardiac diffusion imaging: toward new insights in myocardial ischemia. J Radiol, 90(4):455-457, 2009.
[Girard-09] P. Girard, Quaternion Grassmann-Hamilton-Clifford algebras: new mathematical tools for classical and relativistic modeling. O. Dössel and W.C. Schlegel (Eds): WC 2009, IFMBE Proceedings 25/IV, pp. 65-68, 2009.
[Girard-07] P. R. GIRARD, Quaternions, Clifford Algebras and Relativistic Physics (Birkhauser, Basel, 2007)