The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 2008
Filed:
Dec. 20, 2006
Matahiro Komuro, Hitachi, JP;
Yuichi Satsu, Hitachi, JP;
Takao Imagawa, Mito, JP;
Katsumi Ishikawa, Hitachinaka, JP;
Takeyuki Itabashi, Yasugi, JP;
Matahiro Komuro, Hitachi, JP;
Yuichi Satsu, Hitachi, JP;
Takao Imagawa, Mito, JP;
Katsumi Ishikawa, Hitachinaka, JP;
Takeyuki Itabashi, Yasugi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Eddy current generated around a magnetic circuit in an MRI apparatus is one of the causes of deviation from an ideal magnetic field gradient waveform and causes image distortion, loss of strength, ghost generation, loss of signal, and spectral distortion. An object of the present invention is to suppress the generation of the eddy current. In an MRI apparatus, a ferromagnetic material formed from powder is used in a part of a magnetic circuit: the powder mainly comprising a mother phase containing iron or cobalt and showing ferromagnetism; and a high-resistance layer having a resistance not less than ten times as high as the mother phase and a Vickers hardness lower than that of the mother phase being formed in layers along parts of the surface of the powder on parts or the entire of the surface.