PROBLEM TO BE SOLVED: To solve such the problem that though the resolution of MRI is improved by increasing power of RF (electromagnetic waves) since the RF coil of an MRI apparatus is installed on the inner side of a static magnetic field coil and a gradient magnetic field coil, and a living body is irradiated with the RF in order to obtain nuclear magnetic resonance signals, the potential of the RF coil becomes high when the power of the RF is increased, and thus a structure of sticking a conductor in an arbitrary shape to a hollow cylindrical insulator or the like is formed in order to arrange the RF coil around the living body, but the insulator needs to be thick since the potential becomes high also on the inner side wall surface of the cylindrical insulator when the potential of the RF coil becomes high and a space where the living body enters becomes narrow.SOLUTION: By installing an electrostatic shield and a groove or a hole filled with air or an insulator of a low dielectric constant to an RF coil insulator, an MRI apparatus having an insulation structure of an RF coil capable of increasing RF power without excessively increasing the thickness of the insulator is provided.COPYRIGHT: (C)2013,JPO&INPIT【課題】MRI装置のRFコイルは核磁気共鳴信号を得るために、静磁場コイル、傾斜磁場コイルの内側に設置し、生体にRF(電磁波)を照射する。MRIの解像度はRFのパワーを大きくすることにより向上する。RFのパワーを上げるとRFコイル導体の電位が高くなる。生体の周囲にRFコイルを配置するためには中空の円筒状の絶縁体に任意形状の導体を貼り付ける等の構造とする。しかし、RFコイルの電位が高くなると、円筒状絶縁体の内側壁面も高電位となるため、絶縁体を厚くする必要がある。しかし、生体の入る空間が狭くなる。【解決手段】RFコイル絶縁体に静電シールドと、低誘電率の空気または絶縁体で埋められた溝または穴を設置することにより、絶縁体の厚みを過度に大きくすることなく、RFパワーを大きくできるRFコイルの絶縁構造を有するMRI装置を提供できる。【選択図】 図2
