Abstract: A high-frequency array coil for an MRI apparatus includes: a plurality of coil units each of which includes a plurality of RF reception coils including a conductor loop and adjusted to receive a magnetic resonance signal; an extension conductor which includes a part of each conductor loop of each RF reception coil of the plurality of coil units and a conductor connecting the parts; and an extension conductor control circuit which adjusts a reception frequency of the extension conductor. The extension conductor is disposed so as to be wound in a spiral shape when the extension conductor is disposed on a subject and a direction of a magnetic field to be detected intersects a direction of a magnetic field detected by the RF reception coil constituting the coil unit. Accordingly, the detection efficiency of an RF coil can be increased and an image with a high SNR can be obtained.

Abstract: A high-frequency array coil for an MRI apparatus includes: a plurality of coil units each of which includes a plurality of RF reception coils including a conductor loop and adjusted to receive a magnetic resonance signal; an extension conductor which includes a part of each conductor loop of each RF reception coil of the plurality of coil units and a conductor connecting the parts; and an extension conductor control circuit which adjusts a reception frequency of the extension conductor. The extension conductor is disposed so as to be wound in a spiral shape when the extension conductor is disposed on a subject and a direction of a magnetic field to be detected intersects a direction of a magnetic field detected by the RF reception coil constituting the coil unit. Accordingly, the detection efficiency of an RF coil can be increased and an image with a high SNR can be obtained.

Abstract: In a magnetic resonance imaging device provided with a deformable RF coil permanently mounted on a patient table, the RF coil can constantly maintain a matching state and a tuned state in a state of being flat on a top plate and in a state of being wound around a test object. Coil-side connectors 306-2 and 306-3 provided in a deformable RF coil 300 form a detector in cooperation with any one of fixture-side connectors 506-1 to 506-6, in which the detector detects a fitted state therebetween. A tuning circuit and a matching circuit of coil elements of the RF coil 300 are switched by an output of the detector to change tuning and matching parameters, and to maintain a matching state and a tuned state with respect to a state change indicating that the RF coil 300 is in a wound state.

Abstract: A lower cost MRI device with a portable table detachable from the gantry is provided along with a lower cost table equipped with an easy-to-use and easy-to-install RF coil system able to perform high-resolution head and neck imaging and high-speed whole body imaging in both head-first and feet-first modes. This magnetic resonance imaging device has a portable table detachable from the gantry, and the portable table has a docking connector that can be connected to the gantry and a ceiling panel on which an RF coil can be installed to receive nuclear magnetic resonance signals generated by the examinee and to irradiate the examinee with a high-frequency magnetic field. The RF coil is divided into two or more RF coil units, the ceiling panel has a plurality of ceiling panel connectors enabling each RF coil unit to be connected, and each RF coil unit has a connector.

Abstract: There is provided a technique for suppressing increase of SAR without sacrificing sensitivity in RF coils used in MRI apparatuses. The present invention provides an antenna device comprising a sheet-shaped conductor and a ribbon-shaped conductor disposed on the subject side with respect to the sheet-shaped conductor with a predetermined distance from the sheet-shaped conductor. The ribbon-shaped conductor has a meandering shape, and is adjusted so as to resonate at transmission and reception frequencies, and it is constituted so that distance to the sheet-shaped conductor becomes smaller at both end part thereof along the static magnetic field direction compared with the distance to the sheet-shaped conductor at the center thereof. Moreover, the ribbon-shaped conductor is constituted so as to have a smaller width, as the distance to the sheet-shaped conductor becomes smaller.

Abstract: In a magnetic resonance imaging device provided with a deformable RF coil permanently mounted on a patient table, the RF coil can constantly maintain a matching state and a tuned state in a state of being flat on a top plate and in a state of being wound around a test object. Coil-side connectors 306-2 and 306-3 provided in a deformable RF coil 300 form a detector in cooperation with any one of fixture-side connectors 506-1 to 506-6, in which the detector detects a fitted state therebetween. A tuning circuit and a matching circuit of coil elements of the RF coil 300 are switched by an output of the detector to change tuning and matching parameters, and to maintain a matching state and a tuned state with respect to a state change indicating that the RF coil 300 is in a wound state.

Abstract: There is provided a technique for securing a comfortable examination space in a tunnel type MRI apparatus without increasing the manufacturing cost of the MRI apparatus and sacrificing performance thereof. In an RF coil provided with a hollow-shaped outer conductive element and a strip-shaped conductive element disposed along the outer conductive element in the axial direction, meander lines constituting the strip-shaped conductive element are disposed at uneven distances from the outer conductive element to secure an internal space. In order to obtain uniform sensitivity at the center of the RF coil, the strip-shaped conductive element is constituted with N of connected meander lines, and length of the strip-shaped conductive element is adjusted so that, in the strip-shaped conductive element resonating at resonance frequency of the antenna, nodes are formed in a number of (M+1)×N?1, wherein M is 0 or a natural number of 1 or larger.

Abstract: Manufacture cost and maintenance cost of RF coils of MRI devices are reduced without any limitation concerning size of the coils. By constituting an antenna device for magnetic resonance imaging devices with a cylindrical outer conductor, a looped ribbon-shaped conductor disposed inside the cylindrical outer conductor along the cylindrical surface, and a feed point for transmission and/or reception between the cylindrical conductor and the ribbon-shaped conductor, and disposing the ribbon-shaped conductor so that length thereof can be readily adjusted, there is provided an antenna device for magnetic resonance imaging devices that generates a magnetic field component perpendicular to the central axis of the cylinder at a desired resonance frequency and shows sensitivity without using capacitors and without being imposed any limitation concerning size in the diametral direction of the cylinder.

Abstract: A lower cost MRI device with a portable table detachable from the gantry is provided along with a lower cost table equipped with an easy-to-use and easy-to-install RF coil system able to perform high-resolution head and neck imaging and high-speed whole body imaging in both head-first and feet-first modes. This magnetic resonance imaging device has a portable table detachable from the gantry, and the portable table has a docking connector that can be connected to the gantry and a ceiling panel on which an RF coil can be installed to receive nuclear magnetic resonance signals generated by the examinee and to irradiate the examinee with a high-frequency magnetic field. The RF coil is divided into two or more RF coil units, the ceiling panel has a plurality of ceiling panel connectors enabling each RF coil unit to be connected, and each RF coil unit has a connector.

Abstract: A magnetic resonance imaging apparatus is provided, characterized by: one pair of static magnetic field generating means disposed sandwiching a space in which a test object is placed; magnetic field generating means configured to apply a high-frequency magnetic field and a gradient magnetic field to the test object placed in the static magnetic field; and receiving means configured to receive a nuclear magnetic resonance signal generated from the test object, and characterized in that: the receiving means includes a receiving coil having a predetermined coil pattern and capable of being shaped into a cylinder; the receiving coil includes flexible parts and rigid parts alternately disposed along the circumference direction when shaped into the cylinder; and the flexible parts include a flexible substrate on which a portion of the predetermined coil pattern is mounted and a air-bubbles-containing resin section for covering the both surfaces of the flexible substrate.

Abstract: An RF coil is provided with a hollow-shaped outer conductive element and strip-shaped conductive elements disposed along the outer conductive element in the axial direction. The strip-shaped conductive elements are disposed with uneven intervals to secure an internal space at a position where the strip-shaped conductive elements are not disposed. In order to obtain uniform sensitivity at the center section of the RF coil, the strip-shaped conductive elements and the outer conductive element are electrically connected via capacitors of which capacitances are adjusted so that a magnetic field component perpendicular to the center axis should be generated at a desired resonance frequency, and the strip-shaped conductive elements are axisymmetrically disposed with respect to the center axis of the outer conductive element. As a result, a comfortable examination space in a tunnel type MRI apparatus is achieved without increasing the manufacturing cost of the MRI apparatus.

Abstract: A magnetic resonance imaging apparatus comprises: static magnetic field generation means which generates a static magnetic field in an imaging space where an object to be examined is placed; gradient magnetic field generation means which generates a gradient magnetic field in the imaging space; high-frequency magnetic field generation means which generates a high-frequency magnetic field in the imaging space; calculation means which calculates an amount of the electromagnetic wave absorbed by the object when the high-frequency magnetic field is irradiated to the object; and a measurement means which measures a characteristic of the high-frequency magnetic field generation means. The calculation means calculates the amount of the electromagnetic wave absorbed by the object according to the characteristic of the high-frequency magnetic field generation means measured by the measurement means.

Abstract: There is provided a technique for suppressing increase of SAR without sacrificing sensitivity in RF coils used in MRI apparatuses. The present invention provides an antenna device comprising a sheet-shaped conductor and a ribbon-shaped conductor disposed on the subject side with respect to the sheet-shaped conductor with a predetermined distance from the sheet-shaped conductor. The ribbon-shaped conductor has a meandering shape, and is adjusted so as to resonate at transmission and reception frequencies, and it is constituted so that distance to the sheet-shaped conductor becomes smaller at both end part thereof along the static magnetic field direction compared with the distance to the sheet-shaped conductor at the center thereof. Moreover, the ribbon-shaped conductor is constituted so as to have a smaller width, as the distance to the sheet-shaped conductor becomes smaller.

Abstract: There is provided a technique for securing a comfortable examination space in a tunnel type MRI apparatus without increasing the manufacturing cost of the MRI apparatus and sacrificing performance thereof. In an RF coil provided with a hollow-shaped outer conductive element and a strip-shaped conductive element disposed along the outer conductive element in the axial direction, meander lines constituting the strip-shaped conductive element are disposed at uneven distances from the outer conductive element to secure an internal space. In order to obtain uniform sensitivity at the center of the RF coil, the strip-shaped conductive element is constituted with N of connected meander lines, and length of the strip-shaped conductive element is adjusted so that, in the strip-shaped conductive element resonating at resonance frequency of the antenna, nodes are formed in a number of (M+1)×N?1, wherein M is 0 or a natural number of 1 or larger.

Abstract: The present invention provides a vertical magnetic field MRI apparatus which is capable of speeding up imaging for taking an image of any cross section of a wide area such as a total body, while suppressing increase of the number of channels and maintaining high sensitivity in a deep portion of a subject. A receiver coil unit 500 incorporates a bed coil unit 600 whose longitudinal direction agrees with a body axis direction of the test object 103, and an upper coil unit 700 which is detachably mounted on the bed coil unit 600. The bed coil unit 600 is provided with a carrying surface 601 for placing the test object 103 thereon and multiple lower sub-coils arranged in a lower part of the carrying surface 601, and the upper coil unit 700 is provided with multiple upper sub-coils which are connected to the lower sub-coils.

Abstract: It is an object of the present invention to provide an RF coil and an MRI apparatus capable of ensuring a wide imaging space and excellent in terms of allowing maintenance at the time of installation or failure. In order to do so, an RF coil of the present invention includes a cylindrical outer conductor and a plurality of rung conductors disposed inside the outer conductor along a circumferential direction of the outer conductor. In addition, each of the plurality of rung conductors is electrically connected to the outer conductor through a capacitor so as to form an electrical loop. The outer conductor is divided into a plurality of portions in the circumferential direction and is characterized in that the numbers of rung conductors disposed in at least two divided portions are different. In addition, an MRI apparatus of the present invention includes such an RF coil.

Abstract: This invention provides a receiving coil that allows a high-quality image of high depth sensitivity to be obtained during vertical magnetic field MRI without limiting selection of a cross section to be imaged and of a phase-encoding axis. A subject's field of view is broadened without deterioration of the coil characteristics. Two orthogonal solenoid coils (3-1 and 4-1) and sub-coils (5-1, 6-1, and 7-1) whose sensitivity distributions each become an odd function in an x-direction, a y-direction, and a z-direction, respectively, with respect to the origin of the sensitivity distribution of each of the solenoid coils are used as multiple sub-coils to construct the receiving coil. This receiving coil is suitable for a high-speed imaging method in which an image is acquired using reduced phase encoding and the image is reconstructed using image folding. In addition, the subject's field of view can be broadened by arranging conductors of the coil appropriately.

Abstract: Manufacture cost and maintenance cost of RF coils of MRI devices are reduced without any limitation concerning size of the coils. By constituting an antenna device for magnetic resonance imaging devices with a cylindrical outer conductor, a looped ribbon-shaped conductor disposed inside the cylindrical outer conductor along the cylindrical surface, and a feed point for transmission and/or reception between the cylindrical conductor and the ribbon-shaped conductor, and disposing the ribbon-shaped conductor so that length thereof can be readily adjusted, there is provided an antenna device for magnetic resonance imaging devices that generates a magnetic field component perpendicular to the central axis of the cylinder at a desired resonance frequency and shows sensitivity without using capacitors and without being imposed any limitation concerning size in the diametral direction of the cylinder.

Abstract: A magnetic resonance imaging apparatus comprises: static magnetic field generation means which generates a static magnetic field in an imaging space where an object to be examined is placed; gradient magnetic field generation means which generates a gradient magnetic field in the imaging space; high-frequency magnetic field generation means which generates a high-frequency magnetic field in the imaging space; calculation means which calculates an amount of the electromagnetic wave absorbed by the object when the high-frequency magnetic field is irradiated to the object; and a measurement means which measures a characteristic of the high-frequency magnetic field generation means. The calculation means calculates the amount of the electromagnetic wave absorbed by the object according to the characteristic of the high-frequency magnetic field generation means measured by the measurement means.

Abstract: The present invention provides a vertical magnetic field MRI apparatus which is capable of speeding up imaging for taking an image of any cross section of a wide area such as a total body, while suppressing increase of the number of channels and maintaining high sensitivity in a deep portion of a subject. A receiver coil unit 500 incorporates a bed coil unit 600 whose longitudinal direction agrees with a body axis direction of the test object 103, and an upper coil unit 700 which is detachably mounted on the bed coil unit 600. The bed coil unit 600 is provided with a carrying surface 601 for placing the test object 103 thereon and multiple lower sub-coils arranged in a lower part of the carrying surface 601, and the upper coil unit 700 is provided with multiple upper sub-coils which are connected to the lower sub-coils.