# US 2019/0317166 A1 · Magnetic resonance imaging apparatus, rf coil, and magnetic resonance imaging method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0317166 A1 - Document ID: US20190317166A1 - Status: Published application - Kind: A1 - Application number: 16/381,451 - Filed: 2019-04-11 - Published: 2019-10-17 - Earliest claimed: 2018-04-13 - Assignees: Canon Medical Systems Corporation - Applicants: Canon Medical Systems Corporation - Inventors: Satoshi Imai; Sadanori Tomiha - Web page: https://patentgrep.com/patent/US20190317166A1 ## CPC - G01R 33/4818: {MR characterised by data acquisition along a specific k-space trajectory or by the temporal order of k-space coverage, e.g. centric or segmented coverage of k-space} - G01R 33/246: {Spatial mapping of the RF magnetic field B1} - G01R 33/34046: {Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils} - G01R 33/34076: {Birdcage coils} - G01R 33/3415: comprising arrays of sub-coils {, i.e. phased-array coils with flexible receiver channels} - G01R 33/3456: {Stripline resonators} - G01R 33/3614: {RF power amplifiers} - G01R 33/3657: {Decoupling of multiple RF coils wherein the multiple RF coils do not have the same function in MR, e.g. decoupling of a transmission coil from a receive coil} - G01R 33/56: Image enhancement or correction, e.g. subtraction or averaging techniques {, e.g. improvement of signal-to-noise ratio and resolution} - G01R 33/5611: {Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by Fourier encoding of the overlaps using the temporal dimension [UNFOLD], k-t-broad-use linear acquisition speed-up technique [k-t-BLAST], k-t-SENSE (structural details of arrays of sub-coils G01R33/3415)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract An MRI apparatus according to an embodiment includes a whole body RF coil accommodated in a gantry. The whole body RF coil includes a first element unit used for transmission of a radio frequency magnetic field; and a second element unit used for reception of a magnetic resonance signal produced from a subject having been applied with the radio frequency magnetic field. The first element unit is a birdcage-type RF coil having two end rings and a plurality of rungs spaced apart from each other along the circumferential direction of the end rings. The second element unit is a microstrip antenna. ## Claims ### Claim 1 A magnetic resonance imaging apparatus, comprising a whole body RF coil accommodated in a gantry, the whole body RF coil including: a first element unit used for transmission of a radio frequency magnetic field; and a second element unit used for reception of a magnetic resonance signal produced from a subject having been applied with the radio frequency magnetic field, wherein the first element unit is a birdcage-type RF coil having two end rings and a plurality of rungs spaced apart from each other along a circumferential direction of the end rings, and the second element unit is a microstrip antenna. ### Claim 2 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the second element unit is configured such that a plurality of the microstrip antennas are disposed such that sensitivity distribution in a plane along a second direction and a third direction varies according to a position in a first direction, wherein the first direction is a direction along a magnetic flux of a static magnetic field, the second direction is a direction orthogonal to the first direction, and the third direction is a direction orthogonal to each of the first direction and the second direction. ### Claim 3 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the microstrip antenna is disposed along a rung included in the first element unit and is configured with the rung as a ground conductor. ### Claim 4 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the first element unit is further used for reception of the radio frequency magnetic field. ### Claim 5 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the second element unit is further used for transmission of the radio frequency magnetic field. ### Claim 6 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein in the whole body RF coil, when the first element unit is used, the second element unit and the first element unit are short-circuited. ### Claim 7 (depends on 2) The magnetic resonance imaging apparatus according to claim 2, wherein the second element unit includes a plurality of microstrip antennas each having a length shorter than the first element unit in the first direction and disposed at different positions in the first direction. ### Claim 8 (depends on 2) The magnetic resonance imaging apparatus according to claim 2, wherein the second element unit includes a plurality of microstrip antennas having different lengths in the first direction. ### Claim 9 (depends on 2) The magnetic resonance imaging apparatus according to claim 2, wherein each rung included in the first element unit is disposed diagonally to the first direction, and each microstrip antenna included in the second element unit is disposed along a rung included in the first element unit and is configured with the rung as a ground conductor. ### Claim 10 (depends on 7) The magnetic resonance imaging apparatus according to claim 7, wherein each microstrip antenna included in the second element unit is configured with part of the first element unit as a ground conductor and includes an antenna conductor and a dielectric disposed between the antenna conductor and the ground conductor, and a length in the first direction of the antenna conductor is determined based on at least one of a distance between the antenna conductor and the ground conductor, a material of the dielectric, and a width of the antenna conductor. ### Claim 11 (depends on 8) The magnetic resonance imaging apparatus according to claim 8, wherein each microstrip antenna included in the second element unit is configured with part of the first element unit as a ground conductor and includes an antenna conductor and a dielectric disposed between the antenna conductor and the ground conductor, and a length in the first direction of the antenna conductor is determined based on at least one of a distance between the antenna conductor and the ground conductor, a material of the dielectric, and a width of the antenna conductor. ### Claim 12 (depends on 2) The magnetic resonance imaging apparatus according to claim 2, further comprising a control unit configured to perform parallel imaging using sensitivity distribution of each microstrip antenna included in the second element unit. ### Claim 13 (depends on 12) The magnetic resonance imaging apparatus according to claim 12, wherein the control unit performs the parallel imaging using sensitivity distribution along the first direction of each microstrip antenna. ### Claim 14 An RF coil, comprising: a first element unit used for transmission of a radio frequency magnetic field; and a second element unit used for reception of a magnetic resonance signal produced from a subject having been applied with the radio frequency magnetic field, wherein the first element unit is a birdcage-type RF coil having two end rings and a plurality of rungs spaced apart from each other along a circumferential direction of the end rings, and the second element unit is a microstrip antenna. ### Claim 15 A magnetic resonance imaging method performed by a magnetic resonance imaging apparatus including a whole body RF coil accommodated in a gantry, the whole body RF coil including a first element unit and a second element unit, the first element being a birdcage-type RF coil having two end rings and a plurality of rungs spaced apart from each other along a circumferential direction of the end rings, the second element including a plurality of microstrip antennas, the magnetic resonance imaging method comprising: acquiring first k-space data thinned in a phase encode direction for each of the microstrip antennas by transmitting a radio frequency magnetic field using the first element unit and receiving a magnetic resonance signal using the second element unit, based on a pulse sequence for parallel imaging, the magnetic resonance signal being produced from a subject having been applied with the radio frequency magnetic field; and generating an image by unfolding aliasing in the first k-space data using a sensitivity difference between the microstrip antennas. ### Claim 16 (depends on 15) The magnetic resonance imaging method according to claim 15, further comprising: acquiring second k-space data for each of the microstrip antennas by transmitting a radio frequency magnetic field using the first element unit and receiving a magnetic resonance signal using the second element unit, based on a pulse sequence for measuring sensitivity distribution, the magnetic resonance signal being produced from a subject having been applied with the radio frequency magnetic field; and generating a first sensitivity map indicating sensitivity distribution of the microstrip antenna, for each of the microstrip antennas, based on the second k-space data, wherein the image is generated by unfolding aliasing on image data generated from the first k-space data, using the first sensitivity map, for each of the microstrip antennas. ### Claim 17 (depends on 15) The magnetic resonance imaging method according to claim 15, wherein the first k-space data is acquired so as to include data at a center part of k-space, for each of the microstrip antennas, and the image is generated by performing weighted addition of signal values among the first k-space data acquired for each of the microstrip antennas to unfold aliasing on the first k-space data. ### Claim 18 (depends on 15) The magnetic resonance imaging method according to claim 15, further comprising: acquiring third k-space data by transmitting a radio frequency magnetic field using the first element unit and receiving a magnetic resonance signal using the first element unit, based on a pulse sequence for sensitivity correction, the magnetic resonance signal being produced from a subject having been applied with the radio frequency magnetic field; generating a second sensitivity map indicating sensitivity distribution of the first element unit, based on the third k-space data; and performing sensitivity correction of correcting non-uniformity in the image, using the second sensitivity map.