Speaker: Gabriel Caloz, University of Rennes I
Title: Numerical Simulation of Artifacts in MRI
Abstract:
The technique used to spot information in Magnetic Resonance Imaging
(MRI) is based on electromagnetic fields. To a strong homogeneous
magnetic field (order of magnitude around one Tesla) is added a linearly
varying field (around .01 Tesla per meter). When these fields are
disturbed by the presence of a paramagnetic material in the analyzed
sample for instance, the resulting image is usually distorted; these
distortions are called artifacts.
Our goal is to present a detailed model of the MRI process to construct
the images and then to make numerical simulations.
The first step is to consider the field disturbances. A method to
compute the magnetic field induced by a metallic body embedded in a
uniform external field is presented. It is based on boundary integral
representation formulae for the magnetic induction H. The second step
is to construct the images. The way the images are distorted in
intensity and shape is explained and an algorithm to simulate magnetic
susceptibility artifacts is deduced. Finally some simulations are
presented.
Converted from Caloz.abs (plain text).