US 7,508,207 B2
Magnetic resonance imaging device with sound-absorbing means
Nicolaas Bernardus Roozen, Eindhoven (Netherlands); Robert Paul Kleihorst, Eindhoven (Netherlands); Cornelis Leonardus Gerardus Ham, Eindhoven (Netherlands); and Martijn Roger La Grange, Eindhoven (Netherlands)
Assigned to Koninklijke Philips Electronics N.V., Eindhoven (Netherlands)
Appl. No. 10/557,757
PCT Filed May 17, 2004, PCT No. PCT/IB2004/050709
§ 371(c)(1), (2), (4) Date Nov. 18, 2005,
PCT Pub. No. WO2004/104614, PCT Pub. Date Dec. 02, 2004.
Claims priority of application No. 03101467 (EP), filed on May 22, 2003.
Prior Publication US 2006/0273793 A1, Dec. 07, 2006
Int. Cl. G01V 3/00 (2006.01)
U.S. Cl. 324—318 18 Claims
OG exemplary drawing
 
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.