510312 - PHYSICS OF MEDICAL IMAGING

The course starts with the description of the magnetic resonance phenomenon, of the Bloch equations, of the NMR spectrum and its connection to the free induction decay signal. Then the effects of nuclear dipolar interaction on the spectra are addressed, as well as the modifications of the NMR spectra induced by electron-nucleus hyperfine coupling are presented. Particular emphasis will be given to the effects of the dynamics on the spectra, on the echo signal and on the nuclear spin-lattice relaxation. The second part of the course deals with the Magnetic Resonance Imaging: one-dimensional imaging, the k-space, the gradient-echo, three-dimensional imaging by means of space, phase and frequency encoding. Then the nuclear density, T1 and T2 weighted images will be presented, along with 2D and 3D MRI sequences. Different techniques for image reconstruction will be addressed: the continuous and discrete Fourier transform, sampling and aliasing, projection and backprojection image reconstruction, Radon transform and M-filtering, the X-ray case. Finally diffusion weighted images will be described, the magnetic properties of tissues, the BOLD technique, functional MRI, fast acquisition techniques and the paramagnetic and superparamagnetic contrast agents. Last, an introduction to Radiomics and DTI, through seminars, is presented too.