The subject of this internship is in the field of elastography, i.e. imaging techniques that aim at providing information on mechanical properties of biological tissues . Such techniques are of interest for diagnosis since modifications of these mechanical properties can reveal pathological developments . Basically, the medium is subjected to a stress (quasi static load, shear waves) and the response of the medium is imaged and analyzed to access to the information of interest (e.g. axial strain, shear modulus).
At CREATIS, a displacement and strain estimation method is available, already used to provide axial strain images of breast lesions .
The objective of this internship is to investigate the potentiality of the Virtual Fields Method (VFM) for the reconstruction of mechanical parameters from estimated displacement/strain fields . This technique is based on the virtual work principle and the model of medium considered during these developments will be the linear elastic and isotropic medium.
The method will be assessed using simulations and experiments with phantoms of known mechanical properties imaged with ultrasound.
Skills: The candidate should have strong background in signal and image processing. Good notions in mechanics will also be highly appreciated. Programming language: Matlab.
Location: Laboratoire CREATIS, Bâtiment Blaise Pascal, 7 avenue Jean Capelle, 69100 Villeurbanne
Internship duration: 6 months.
Starting date: February/March 2019.
Allowance : ~560 euros/month.
 K.J. Parker, M.M. Doyley, D.J. Rubens, “Imaging the elastic properties of tissue: the 20 year perspective”, Phys Med Biol, vol. 56, pp. R1–R29, 2011.
 A. Itoh, E. Ueno, E. Tohno, H. Kamma, H. Takahashi, T. Shiina, M. Yamakawa, T. Matsumura, “Breast disease: Clinical application of US elastography for diagnosis”, Radiology, vol. 239, pp. 341–350, 2006.
 E. Brusseau, V. Detti, A. Coulon, E. Maissiat, N. Boublay, Y. Berthezène, J. Fromageau, N. Bush, J. Bamber, « In vivo response to compression of 35 breast lesions observed with a two-dimensional locally regularized strain estimation method », Ultrasound in Medicine and Biology, vol.40, pp.300−312, 2014.
 N. Connesson, E.H. Clayton, P.V. Bayly, F Pierron, « Extension of the optimised virtual fields method to estimate viscoelastic material parameters from 3D dynamic displacement fields”, Strain, vol. 51, pp. 110-134, 2015.