Patent ID: 7508207
Filing Date: 2009-03-24
Classification: G01R

Abstract:
1. A magnetic resonance imaging (MRI) device comprising: a diagnostic space, a main magnetic system for generating a main magnetic field in said diagnostic space, a gradient magnetic coil system comprising a gradient coil for generating at least one gradient of the main magnetic field, and noise reducing means for reducing noise that is generated as a result of vibrations of the gradient coil, wherein the noise reducing means comprise a sound-absorbing panel disposed between the gradient coil and the diagnostic space wherein the sound-absorbing panel comprises channels having an open end and a closed end, wherein at least one of: the channels extend at least substantially perpendicularly to the direction between the diagnostic space and the gradient coil, at least on the side of their closed ends; a cross dimension of at least a part of the channels on the side of the associated open ends is maximally 15 mm, preferably maximally 10 mm; minimum spacing between adjacent channels at the location of the associated maximum cross dimension of the adjacent channels is maximally 50% of the sum of the associated maximum cross dimensions, preferably maximally 35% of the sum of the associated maximum cross dimensions; dimensions of the channels of the sound-absorbing panel are mutually different; the sound absorbing panel is built up of a number of abutting, preferably glued-together subpanels; or the sound-absorbing panel is coated between the open ends with a sound-absorbing material having an absorption coefficient of at least 0.5 for at least part of the frequency range between 20 Hz and 4000 Hz.