Gilles Puy1,2, Jos Marques2,3,
Rolf Gruetter2,3, Jean-Philippe Thiran1, Dimitri Van De
1Institute of Electrical Engineering, Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, Switzerland; 2Institute of the Physics of Biological Systems, Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, Switzerland; 3Department of Radiology, University of Lausanne (UNIL), Lausanne, Switzerland; 4Institute of Bioengineering, Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, Switzerland; 5Department of Radiology & Medical Informatics, University of Geneva (UniGE), Geneva, Switzerland
We advocate a spread spectrum technique for accelerated MRI. The method, justified by the compressed sensing theory, resides in pre modulating the signal by a linear chirp before uniform random k-space undersampling. Numerical simulations confirm the theoretical prediction according to which the pre-modulation is essential in enhancing the signal reconstruction quality. The chirp modulation was implemented on a 7T scanner with the use of a second order shim coil. Results from 3D single coil phantom and in vivo data acquisitions already exhibit slightly better reconstruction qualities than state of the art variable density sampling methods.