Title:
【発明の名称】力を最適化された傾斜コイルを備えた磁気共鳴装置
Document Type and Number:
Japanese Patent JP2001509726
Kind Code:
A
Abstract:
The gradient coil system in a conventional MRI apparatus is optimized in respect of the shielding effect by the shielding coil of the system. Consequently, the system generally is not optimized in respect of the Lorentz forces occurring in the system, resulting in noise of a level such that it is annoying to the users. In order to avoid such noise, the system can be force-optimized. Because the shielding effect is partly lost in that case, however, eddy currents and hence disturbing noise would occur again. However, if the eddy currents are made to occur in acoustically insulated eddy current conductors which also have a large time constant for the decay of the eddy currents, the adverse effects of these eddy currents are adequately counteracted and the disturbing noise is reduced to an adequate extent. Particularly, the (cold) radiation shields of a cryogenic magnet system, arranged in vacuum, can be used as eddy current conductors. The vacuum then constitutes the acoustic insulation.
Inventors:
Ham, Cornelis Leonardus Heraldus
Application Number:
JP53041299A
Publication Date:
July 24, 2001
Filing Date:
October 22, 1998
Export Citation:
Assignee:
Konin Krekka Philips Electronics NV
International Classes:
A61B5/055; G01R33/385; G01R33/20; (IPC1-7): A61B5/055; G01R33/20; G01R33/385
Attorney, Agent or Firm:
Tadahiko Ito (1 outside)