Patent application number | Description | Published |
20090040664 | ACTIVE SHIELD SUPERCONDUCTING ELECTROMAGNET APPARATUS AND MAGNETIC RESONANCE IMAGING SYSTEM - The active shield superconducting electromagnet apparatus includes: a main switching circuit in which first and second main coils, first and second shield coils, and a first superconducting persistent current switch are connected in series; a sub switching circuit in which a bypass circuit, in which a superconducting fault current limiter and a second superconducting persistent current switch are connected in series, are connected to a series circuit of the first main coil and the second main coil in parallel; a first closed circuit in which at least one of the first main coil and the first shield coil, and a first quench protection circuit are connected in series; and a second closed circuit in which one of the second main coil and the second shield coil, and a second quench protection circuit are connected in series. | 02-12-2009 |
20090189721 | SUPERCONDUCTING MAGNET AND MAGNETIC RESONANCE IMAGING APPARATUS - In a superconducting magnet, including a vacuum vessel, a coil vessel inside the vacuum vessel, and a superconducting coil inside the coil vessel for generating a magnetic field, has a magnetic member, disposed inside the vacuum vessel, supported with thermal insulation, for compensating the magnetic field; a heat exchange device disposed outside the vacuum vessel for supplying to or absorbing heat from the vacuum vessel; and thermal conducting members thermally connecting the heat exchange device via the vacuum vessel to the magnetic member. An MRI including the superconducting magnet is also disclosed. | 07-30-2009 |
20100194393 | GRADIENT COIL DEVICE, MAGNETIC RESONANCE IMAGING DEVICE, AND METHOD OF DESIGNING COIL PATTERN - There is provided a gradient coil device which can suppress any generation of an error magnetic field and thus an eddy current, and which can improve the image quality of a cross-sectional image. An MRI device includes a first coil generating a linear magnetic field distribution at an imaging region of the MRI device, and a second coil which suppresses any leakage of a magnetic field from the first coil to a static-magnetic-field coil device that generates a uniform magnetic field distribution at the imaging region. | 08-05-2010 |
20100321019 | GRADIENT MAGNETIC FIELD COIL DEVICE AND MAGNETIC RESONANCE IMAGING APPARATUS - When the gradient magnetic field | 12-23-2010 |
20110037469 | Electromagnet Device and Magnetic Resonance Imaging Device - An electromagnet device which generates magnetic field in the direction perpendicular to the inserting direction of an inspection subject is reduced in size and weight by removing unnecessary arrangement as much as possible. A magnetic resonance imaging device is also provided. The electromagnet device comprises a first coil ( | 02-17-2011 |
20110057655 | SOFTWARE FOR ADJUSTING MAGNETIC HOMOGENEITY, METHOD FOR ADJUSTING MAGNETIC HOMOGENEITY, MAGNET DEVICE, AND MAGNETIC RESONANCE IMAGING APPARATUS - On the basis of the magnetic field intensity distribution of a magnetic field space ( | 03-10-2011 |
20110089943 | MAGNETIC FIELD ADJUSTMENT FOR MRI APPARATUS - A measured error magnetic field distribution is divided into eigen-mode components obtained by a singular decomposition and iron piece arrangements corresponding to respective modes are combined and arranged on a shim-tray. An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being known, an erroneous adjustment can also be known, and the adjustment is automatically done during repeated adjustments. As a result, an apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of being able to detect a poor magnet earlier by checking the attainable homogeneity. | 04-21-2011 |
20120176137 | GRADIENT MAGNETIC FIELD COIL AND MAGNETIC RESONANCE IMAGING DEVICE - In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A | 07-12-2012 |
20120235685 | GRADIENT COIL, MAGNETIC RESONANCE IMAGING DEVICE, AND METHOD FOR DESIGNING COIL PATTERN - A method for designing a coil pattern, whereby the production of an error magnetic field and further an eddy current can be suppressed to improve the quality of a cross-sectional image irrespective of cylindrical cross-sectional shape of the main coil and the shield coil. The difference between the initial values of the target magnetic field and the magnetic field vector is set as a difference target magnetic field. An approximate value of the current potential vector that produces the difference target magnetic field is represented by a polynomial of an eigenvector group of the current potential. The coefficient of each of the terms of the polynomial is determined on the basis of the singular value and the eigenvector group of the magnetic field distribution. | 09-20-2012 |
20120268119 | MAGNETIC FIELD ADJUSTMENT METHOD FOR MRI DEVICE - An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being grasped, an erroneous adjustment can be grasped, and the adjustment is automatically done during repeated adjustment. When the magnetic field adjustment is carried out with support by the method of the present invention according to the first and second embodiments or an apparatus including this method therein, the magnetic field adjustment can be surely completed. As a result, the apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of earlier detection of a poor magnet by checking the attainable homogeneity. They are applicable to magnet devices for the horizontal magnetic field type, being an open type MRI, and vertical magnetic field type MRI. | 10-25-2012 |
20130335088 | GRADIENT COIL DEVICE AND MAGNETIC RESONANCE IMAGING DEVICE - A gradient coil device includes a major axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a major axis direction of the ellipse at a magnetic field space; and a minor axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a minor axis direction of the ellipse at the magnetic field space. A length of the minor axis field coil in the center axis direction is shorter than a length of the major axis gradient coil in the center axis direction. A maximum value of a residual magnetic field generated by the minor axis gradient coil at a space outside the magnetic field space is equal to or smaller than a maximum value of a residual magnetic field generated by the major axis gradient coil at a space outside the magnetic field space. | 12-19-2013 |