CN113552513A - High-frequency coil, magnetic resonance imaging apparatus, and data transmission method - Google Patents
High-frequency coil, magnetic resonance imaging apparatus, and data transmission method Download PDFInfo
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Abstract
The invention provides a high-frequency coil, a magnetic resonance imaging apparatus and a data transmission method. Embodiments disclosed in the present specification and the accompanying drawings relate to a high-frequency coil, a magnetic resonance imaging apparatus, and a data transmission method. One of the problems to be solved by the embodiments disclosed in the present specification and the drawings is to prevent an image artifact caused by EMI. The high-frequency coil of the embodiment is a high-frequency coil of a magnetic resonance imaging device, and is provided with a channel aggregator, a data receiving unit, and a non-conductive millimeter wave waveguide. The channel aggregator receives signals over a plurality of channels. The data receiving unit receives data from a high-frequency coil antenna for each of the channels. The non-conductive millimeter wave waveguide transmits the data output from the data receiving unit to the channel aggregator for each of the channels. The non-conductive millimeter wave waveguide includes a millimeter wave transmitter, a millimeter wave receiver, and a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver.
Description
Reference to related applications:
this application enjoys the benefit of priority from U.S. patent application nos. 16/857 and 578, filed 24/2020 and japanese patent application No. 2021-042000, filed 16/3/2021, the entire contents of which are incorporated herein by reference.
Technical Field
Embodiments disclosed in the present specification and the accompanying drawings relate to a high-frequency coil, a magnetic resonance imaging apparatus, and a data transmission method.
Background
Magnetic Resonance Imaging (MRI) is a technique used to image soft tissue constructs. In MRI, a high frequency is applied to a nucleus, such as a proton, in a strong external magnetic field. The protons relax after being excited and release a high Frequency (RF) signal, which is detected and computer processed to form an image. Therefore, in a separate MR examination, RF coils for receiving the transmitted RF signals are required.
Here, in the receiving coil unit, a digital interface is sometimes used. In this case, an Analog to Digital (ADC) conversion may be performed in a receiving coil unit including an RF coil and a receiver. When the number of elements (elements) in the coil is large, the size and operability of the connector and the cable become problems, but the above problems can be solved by using a small number of optical fibers or cables in combination with information of a plurality of elements. Comparing the digital interface for the coil with other available technologies and devices, the digital data transmission and combined solutions are highly appreciated in terms of cost, size, and power efficiency. Furthermore, the digital solution has the advantage that additional control and acquisition functions can be added to the coil at little cost. For example, a function of tuning (tuning) the transmission coil for self-test of the coil, control of an intensive solution for making power supply to the coil more efficient, and the like can be added.
In such a receiving coil unit, there are many proposals for bringing an ADC close to an analog front end, but in these proposals, there is a possibility that an artifact (artifact) may occur in an image due to EMI (electromagnetic Interference) radiated and conducted from digital data transmission and a spectrum related thereto.
Disclosure of Invention
One of the problems to be solved by the embodiments disclosed in the present specification and the drawings is to prevent an image artifact caused by EMI. However, the problems to be solved by the embodiments disclosed in the present specification and the drawings are not limited to the above problems. Problems corresponding to the effects of the configurations shown in the embodiments described below can be set as other problems.
The high-frequency coil of the embodiment is a high-frequency coil of a magnetic resonance imaging apparatus, and includes a channel aggregator (channel aggregator), a data receiving unit, and a non-conductive millimeter wave waveguide. The channel aggregator receives signals over a plurality of channels. The data receiving unit receives data from a high-frequency coil antenna for each of the channels. The non-conductive millimeter wave waveguide transmits the data output from the data receiving unit to the channel aggregator for each of the channels. The non-conductive millimeter wave waveguide includes a millimeter wave transmitter, a millimeter wave receiver, and a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver.
The invention has the following effects:
according to the high-frequency coil, the magnetic resonance imaging apparatus, and the data transmission method of the embodiments, it is possible to prevent an image artifact caused by EMI.
Drawings
Fig. 1 is a diagram showing an outline of a typical digital RF coil.
Fig. 2 is a diagram showing an outline of an 8-channel digital RF coil according to the present invention.
Fig. 3 is a diagram showing details of a non-conductive millimeter wave waveguide included in the 8-channel digital RF coil of the present application.
Fig. 4 is a diagram showing details of the millimeter wave transmitter and the millimeter wave receiver of the present application and their connection to the plastic waveguide.
Fig. 5 is a diagram showing an exemplary layout of an 8-channel digital RF coil according to the present application.
Fig. 6 is a diagram showing a configuration of a channel aggregator according to the present invention.
Fig. 7 is a diagram showing a configuration example of an MRI apparatus according to the present application.
Detailed Description
Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application and not present in all embodiments.
Therefore, the expressions "in one embodiment" or "in one embodiment" described in various places throughout the specification do not necessarily refer to the same embodiment of the present application. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
First, a typical digital RF coil will be described with reference to fig. 1.
Fig. 1 shows a typical digital RF coil 101 having an ADC 102 per channel, and channel aggregators 103 arranged close to each other in a shielded box (shielded box). The digital RF coil 101 includes 8 channels 104-105. Each ADC 102 has an analog front end 106 and is connected to an RF coil antenna 107 associated with the corresponding channel.
As for such a configuration, there are proposed a plurality of schemes for bringing the ADC close to the analog front end, but those are not practical. This is because these proposals are carried out at increased cost, or because of digital data transmission and EMI radiated and conducted from the spectrum associated therewith, artifacts are generated in the image.
In current digital RF coil architectures, two different transmission lines, an electrical (e.g., coaxial, 3-axis) transmission line or an optical fiber transmission line, are used for transmitting digital acquisition data.
However, both of these kinds of transmission lines have problems.
Electrical transmission lines present two problems. Since data transmission between the ADC and the channel aggregator generates an artifact in an image due to EMI, the ADC needs to be disposed in the vicinity of the channel aggregator. High filtering, shielding, and electrical isolation of the PC substrate layout are required to suppress EMI noise, but these tend to cause high common mode (common mode) currents from the MR transmit field. Therefore, a cable trap (cable trap) is used to cope with a high common mode current. However, the weight and thickness thereof reduce the convenience of use for the operator, and in addition, the cost thereof is also high.
One disadvantage with optical fiber transmission lines is the high cost associated therewith. Laser transmitters and receivers are, for example, higher cost semiconductors (e.g., GaAs) than standard CMOS (Complementary Metal-Oxide Semiconductor) devices. Furthermore, the connector of the optical fiber consumes high power, and the RF coil is heated to raise the surface temperature to the limit of safe operation.
The present disclosure includes devices and methods for transmitting digital acquisition data within an RF coil of an MRI device using a non-conductive waveguide. Connectionless standard CMOS Millimeter Wave (mmWave) receivers and transmitters are used for the link between the ADC and the channel aggregator for each channel in the RF coil. Further, in order to transmit data between the transmitter and the receiver of the millimeter wave, a non-conductive waveguide (for example, a waveguide of polytetrafluoroethylene) is used.
The radio frequency coil, the magnetic resonance imaging apparatus, and the data transmission method according to the present invention will be described in detail below with reference to fig. 2 to 7.
Fig. 2 is an exemplary embodiment of an 8-channel digital MR-RF coil 201 representing the present application. Here, an 8-channel digital MR-RF coil is an example of a high-frequency coil. The 8-channel digital MR-RF coil 201 of the application comprises 8 channels 204-205, and the 8 channels 204-205 receive RF signals transmitted by a single MR examination. In each channel, an amplification and data digitization unit 210, which includes an analog front end 206 and an ADC 202, receives signals from the RF coil antenna 207 and transmits the received signals to the channel aggregator 203 via corresponding non-conductive millimeter wave waveguides 211. Here, the amplifying and data digitizing means is an example of the data receiving section. The channel aggregator 203 transmits signals to and from the MR system via optical fibers or non-conductive millimeter wave waveguides 216.
Each amplification and data digitization unit 210 includes an ADC 202 and an analog front end 206.
Each of the nonconductive millimeter wave waveguides 211 includes a millimeter wave transmitter 208 at one end portion that receives a signal from the amplification and data digitization unit 210, and a millimeter wave receiver 209 at the other end portion that is connected to the channel aggregator 203. The millimeter wave transmitter 208 and the millimeter wave receiver 209 are connected via a plastic waveguide 212. Here, a plastic waveguide is an example of a waveguide. The ADCs 202 of the various channels are connected via a control path 213, which control path 213 is likewise connected to the channel aggregator 203 via a non-conductive millimeter wave waveguide 211.
For encoding the data stream, an 8B/10B coding scheme (encoding scheme) may also be used. The 8B/10B coding scheme ensures DC balance of the integrity of the serial data stream and, in addition, the downstream receiver provides sufficient bit (bit) conversion to be able to maintain clock recovery.
Fig. 3 shows details of a non-conductive millimeter wave waveguide 311 for use in the 8-channel digital MR-RF coil of the present application.
Specifically, a millimeter wave transmitter 308 and a millimeter wave receiver 309 are disposed at each end of the plastic waveguide 312. In one embodiment, the plastic waveguide 312 comprises Polytetrafluoroethylene (PTFE) or other low cost non-conductive plastic or polymer.
In addition, here, an example of a case where a plastic waveguide is used as a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver is described, but the embodiment is not limited thereto. For example, a waveguide formed of glass (quartz or the like), acrylic (acrylic), polycarbonate (polycarbonate), polymer (polymethyl methacrylate) resin, or the like may be used.
The millimeter wave transmitter 308 includes a transmitter Integrated Circuit (IC) having an Integrated millimeter wave transmission antenna 313, and the Integrated millimeter wave transmission antenna 313 is coupled to the plastic waveguide 312 via a plastic waveguide coupler 315. Further, the millimeter wave receiver 309 is provided with a receiver IC having an integrated millimeter wave receiving antenna 314 at the other end of the data transmission link, the integrated millimeter wave receiving antenna 314 being coupled with the plastic waveguide 312 via a plastic waveguide coupler 316. Here, a plastic waveguide coupler is an example of the waveguide coupler. In one embodiment, the transmitter IC and the receiver IC comprise standard CMOS devices or other low cost semiconductor devices.
Fig. 4 shows details of millimeter wave transmitter 408 and millimeter wave receiver 409 of the present application and their connection to the plastic waveguide. In one embodiment, millimeter wave transmitter 408 is provided with a plastic waveguide coupler 415 mounted on top of integrated millimeter wave transmit antenna 413. When the wave is emitted from the integrated millimeter wave transmitting antenna 413, for example, Er 1.0 is set as a propagation mode, and the outer field of the coupler (Er 1.0) is attenuated by an exponential function. The plastic waveguide 412 is inserted into the respective opening portions of the plastic waveguide couplers 415 and 416. Also, in millimeter wave receiver 409, plastic waveguide coupler 416 is mounted on the upper portion of integrated millimeter wave receiving antenna 414.
Fig. 5 is an exemplary layout of an 8-channel digital MR-RF coil 501 representing the present application. In one embodiment, an array of loop antennas, an amplification and acquisition data digitization unit, a non-conductive millimeter wave waveguide, and a channel aggregator are disposed on the substrate 517.
Specifically, 8 loop antennas 507 are symmetrically arranged on one side of each of the corresponding 8 nonconductive millimeter wave waveguides 511. The amplification and data digitization unit 510 is connected to the corresponding loop antenna 507 via an electrical connection 518, and transmits the received data to the channel aggregator 503 disposed on the side of the substrate 517 via the corresponding non-conductive millimeter wave waveguide 511 for each channel. The digital data received by the channel aggregator 503 is transceived with the MR system via the optical fiber or the non-conductive millimeter wave waveguide 516.
Fig. 6 shows a configuration of a channel aggregator 601 of the present application. The channel aggregator 601 receives input signals 602-603 from different channels. Here, each input signal is a serial data stream of a bit rate (bit rate) X. A buffer 604 within the channel aggregator 601 receives the input stream and sends the data to a dual port RAM (Random Access Memory) 605. The channel aggregator 601 outputs the data as a serial stream at a bit rate of X (n + 1).
Fig. 7 is a diagram showing a configuration example of an MRI apparatus according to the present application.
For example, as shown in fig. 1, the MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil 2, a gradient magnetic field power supply 3, a whole-body RF (Radio Frequency) coil 4, a local RF coil 5, a transmission circuit 6, a reception circuit 7, an RF shield 8, a gantry 9, a couch 10, an input interface 11, a display 12, a storage circuit 13, and processing circuits 14 to 16.
The static magnetic field magnet 1 generates a static magnetic field in an imaging space in which the subject S is disposed. Specifically, the static magnetic field magnet 1 is formed in a hollow substantially cylindrical shape (a shape including a cross section orthogonal to the central axis is an elliptical shape), and generates a static magnetic field in an imaging space formed on the inner peripheral side thereof. The static field magnet 1 is, for example, a superconducting magnet or a permanent magnet. The superconducting magnet referred to herein is constituted by a vessel filled with a coolant such as liquid helium (helium) and a superconducting coil immersed in the vessel.
The gradient coil 2 is disposed inside the static field magnet 1, and generates a gradient magnetic field in an imaging space in which the subject S is disposed. Specifically, the gradient coil 2 is formed in a hollow substantially cylindrical shape (a shape including a cross section orthogonal to the central axis is an elliptical shape), and includes an X coil, a Y coil, and a Z coil corresponding to an X axis, a Y axis, and a Z axis orthogonal to each other. The X coil, the Y coil, and the Z coil generate a gradient magnetic field in the imaging space, which linearly changes in each axial direction, based on a current supplied from the gradient magnetic field power supply 3. Here, the Z axis is set to a magnetic flux along the static magnetic field generated by the static field magnet 1. The X axis is set along a horizontal direction orthogonal to the Z axis, and the Y axis is set along a vertical direction orthogonal to the Z axis. Thus, the X-axis, Y-axis, and Z-axis constitute an apparatus coordinate system unique to the MRI apparatus 100.
The gradient magnetic field power supply 3 supplies a current to the gradient magnetic field coil 2, thereby generating a gradient magnetic field in the imaging space. Specifically, the gradient magnetic field power supply 3 supplies currents to the X coil, the Y coil, and the Z coil of the gradient magnetic field coil 2 individually, thereby generating a gradient magnetic field in the imaging space that linearly changes in the readout (readout) direction, the phase encoding direction, and the slice (slice) direction, which are orthogonal to each other. Hereinafter, the gradient magnetic field along the readout direction is referred to as a readout gradient magnetic field, the gradient magnetic field along the phase encoding direction is referred to as a phase encoding gradient magnetic field, and the gradient magnetic field along the slice direction is referred to as a slice gradient magnetic field.
Here, the readout gradient magnetic field, the phase encode gradient magnetic field, and the slice gradient magnetic field are superimposed on the static magnetic field generated by the static magnetic field magnet 1, respectively, to provide spatial position information on the magnetic resonance signal generated from the subject S. Specifically, the readout gradient magnetic field changes the frequency of the magnetic resonance signal in accordance with the position in the readout direction, thereby giving the magnetic resonance signal position information along the readout direction. The phase encoding gradient magnetic field changes the phase of the magnetic resonance signal in the phase encoding direction, thereby giving the magnetic resonance signal positional information in the phase encoding direction. Furthermore, the slice gradient magnetic field imparts positional information along the slice direction to the magnetic resonance signals. For example, when the imaging region is a slice region (2D imaging), the slice gradient magnetic field is used to determine the direction, thickness, and number of slices, and when the imaging region is a volume region (3D imaging), the slice gradient magnetic field is used to change the phase of the magnetic resonance signal according to the position in the slice direction. Thus, an axis along the readout direction, an axis along the phase encode direction, and an axis along the slice direction constitute a logical coordinate system for defining a slice region or volume region to be imaged.
The whole-body RF coil 4 is disposed on the inner peripheral side of the gradient magnetic field coil 2, applies an RF magnetic field (excitation pulse or the like) to the subject S disposed in the imaging space, and receives a magnetic resonance signal (echo signal or the like) generated from the subject S by the RF magnetic field. Specifically, the whole-body RF coil 4 is formed in a hollow substantially cylindrical shape (a shape including a cross section orthogonal to the central axis is an elliptical shape), and applies an RF magnetic field to the subject S disposed in the imaging space located on the inner peripheral side thereof based on the RF pulse supplied from the transmission circuit 6. The whole-body RF coil 4 receives a magnetic resonance signal generated from the subject S due to the influence of the RF magnetic field, and outputs the received magnetic resonance signal to the receiving circuit 7.
The local RF coil 5 receives a magnetic resonance signal generated from the subject S. Specifically, the local RF coil 5 is prepared for each part of the subject S, and when imaging the subject S, the local RF coil 5 is disposed near the surface of the part to be imaged. The local RF coil 5 receives a magnetic resonance signal generated from the subject S under the influence of the RF magnetic field applied by the whole-body RF coil 4, and outputs the received magnetic resonance signal to the receiving circuit 7. The local RF coil 5 may also have a function of applying an RF magnetic field to the subject S. In this case, the local RF coil 5 is connected to the transmission circuit 6, and applies an RF magnetic field to the subject S based on an RF pulse supplied from the transmission circuit 6. For example, the local RF coil 5 is a surface coil (surface coil) or a phased array coil (phased array coil) configured by combining a plurality of surface coils into a coil element. Here, the local RF coil 5 has the configuration of the 8-channel digital RF coil described above.
The transmission circuit 6 outputs an RF pulse corresponding to a Larmor (Larmor) frequency specific to the target nucleus placed in the static magnetic field to the whole body RF coil 4.
The receiving circuit 7 generates magnetic resonance data based on the magnetic resonance signal output from the whole-body RF coil 4 or the local RF coil 5, and outputs the generated magnetic resonance data to the processing circuit 15. Here, the receiving circuit 7 corresponds to the MR system described above.
The RF shield 8 is disposed between the gradient coil 2 and the whole-body RF coil 4, and shields the gradient coil 2 from the RF magnetic field generated by the whole-body RF coil 4. Specifically, the RF shield 8 is formed in a hollow substantially cylindrical shape (a shape including a cross section perpendicular to the central axis of the cylinder is an elliptical shape), and is disposed in a space on the inner peripheral side of the gradient coil 2 so as to cover the outer peripheral surface of the whole-body RF coil 4.
The gantry 9 has a hollow cavity (bore)9a formed in a substantially cylindrical shape (a shape including an elliptical cross section perpendicular to the central axis), and houses the static field magnet 1, the gradient coil 2, the whole body RF coil 4, and the RF shield 8. Specifically, the gantry 9 houses the whole-body RF coil 4 on the outer periphery of the cavity 9a, the RF shield 8 on the outer periphery of the whole-body RF coil 4, the gradient coil 2 on the outer periphery of the RF shield 8, and the static field magnet 1 on the outer periphery of the gradient coil 2. Here, the space in the cavity 9a of the gantry 9 is an imaging space in which the subject S is disposed during imaging.
The bed 10 includes a top plate 10a on which the subject S is placed, and moves the top plate 10a on which the subject S is placed into the imaging space when imaging the subject S. For example, the bed 10 is provided such that the longitudinal direction of the top plate 10a is parallel to the central axis of the static field magnet 1.
Here, an example in which the MRI apparatus 100 has a so-called tunnel (tunnel) type structure in which the static field magnet 1, the gradient magnetic field coil 2, and the whole-body RF coil 4 are each formed in a substantially cylindrical shape has been described, but the embodiment is not limited to this. For example, the MRI apparatus 100 may have a so-called open (open) structure in which a pair of static field magnets, a pair of gradient field coils, and a pair of RF coils are arranged so as to face each other with an imaging space in which the subject S is arranged interposed therebetween. In such an open structure, a space sandwiched by the pair of static field magnets, the pair of gradient field coils, and the pair of RF coils corresponds to a cavity in the tunnel structure.
The input interface 11 receives various instructions and input operations of various information from an operator. Specifically, the input interface 11 is connected to the processing circuit 17, converts an input operation received from an operator into an electric signal, and outputs the electric signal to the processing circuit 17. The input interface 11 is realized by, for example, a trackball for setting imaging conditions and a Region Of Interest (ROI), a switch button, a mouse, a keyboard, a touch panel for performing input operations by touching an operation surface, a touch panel in which a display screen and the touch panel are integrated, a non-contact input circuit using an optical sensor, a voice input circuit, and the like. In the present specification, the input interface 11 is not limited to a physical operation member including a mouse, a keyboard, and the like. For example, a processing circuit that receives an electric signal corresponding to an input operation from an external input device provided independently of the apparatus and outputs the electric signal to the control circuit is also included in the input interface 11.
The display 12 displays various information. Specifically, the display 12 is connected to the processing circuit 17, and converts data of various kinds of information sent from the processing circuit 17 into electric signals for display and outputs the electric signals. The display 12 is realized by, for example, a liquid crystal monitor, a CRT monitor, a touch panel, or the like.
The memory circuit 13 stores various data. Specifically, the memory circuit 13 is connected to the processing circuits 14 to 17, and stores various data input/output through each processing circuit. The Memory circuit 13 is implemented by a semiconductor Memory element such as a RAM (Random Access Memory) or a flash Memory, a hard disk, an optical disk, or the like.
The processing circuit 14 has a couch control function 14 a. The bed control function 14a outputs a control electric signal to the bed 10, thereby controlling the operation of the bed 10. For example, the couch control function 14a operates the movement mechanism of the top plate 10a included in the couch 10 so as to receive an instruction to move the top plate 10a in the longitudinal direction, the vertical direction, or the horizontal direction from the operator via the input interface 11, and move the top plate 10a in accordance with the received instruction.
The processing circuit 15 has a data acquisition function 15 a. The data acquisition function 15a acquires k-space data by executing various pulse sequences. Specifically, the data acquisition function 15a executes various pulse sequences by driving the gradient magnetic field power supply 3, the transmission circuit 6, and the reception circuit 7 in accordance with the sequence execution data output from the processing circuit 17. Here, the sequence execution data is data indicating a pulse sequence, and is information specifying the timing at which the gradient magnetic field power supply 3 supplies a current to the gradient magnetic field coil 2 and the intensity of the supplied current, the timing at which the transmission circuit 6 supplies an RF pulse to the whole-body RF coil 4 and the intensity of the supplied radio-frequency pulse, the timing (timing) at which the reception circuit 7 samples (samples) a magnetic resonance signal, and the like. Also, the data acquisition function 15a receives the magnetic resonance data output from the reception circuit 7 as a result of execution of the pulse sequence, and stores it in the storage circuit 13. At this time, the magnetic resonance data stored in the storage circuit 13 is given with positional information in each of the readout direction, the phase encoding direction, and the slice direction by the above-described gradient magnetic fields, and is stored as k-space data representing a two-dimensional or three-dimensional k-space.
The processing circuit 16 has an image generating function 16 a. The image generation function 16a generates an image from the k-space data acquired by the processing circuit 15. Specifically, the image generating function 16a reads out k-space data acquired by the processing circuit 15 from the storage circuit 13, and performs reconstruction processing such as Fourier (Fourier) conversion on the read-out k-space data to generate a two-dimensional or three-dimensional image. Then, the image generating function 16a stores the generated image in the storage circuit 13.
The processing circuit 17 has an image pickup control function 17 a. The imaging control function 17a controls each component of the MRI apparatus 100 to perform overall control of the MRI apparatus 100. Specifically, the imaging control function 17a displays a GUI (Graphical User Interface) for receiving various instructions and input operations of various information from the operator on the display 12, and controls each component of the MRI apparatus 100 in accordance with the input operations received via the input Interface 11. For example, the imaging control function 17a generates sequence execution data based on the imaging conditions input by the operator, and outputs the generated sequence execution data to the processing circuit 15, thereby acquiring k-space data. Further, for example, the imaging control function 17a controls the processing circuit 16 to reconstruct an image from the k-space data acquired by the processing circuit 15. Further, for example, the imaging control function 17a reads out an image from the storage circuit 13 in response to a request from the operator, and causes the display 12 to display the read-out image.
Here, the processing circuits 14 to 17 are realized by a processor, for example. In this case, the processing functions of the processing circuits are stored in the storage circuit 13 in the form of a program that can be executed by a computer, for example. Each processing circuit reads out each program from the storage circuit 13 and executes the program, thereby realizing a processing function corresponding to each program. In other words, each processing circuit in which the state of each program is read has each function shown in each processing circuit of fig. 1.
In addition, although the case where each processing circuit is realized by a single processor has been described here, the present invention is not limited to this, and each processing circuit may be configured by combining a plurality of independent processors, and each processing function may be realized by each processor executing a program. Further, the processing functions of the processing circuits may be distributed or integrated in a single or a plurality of processing circuits as appropriate. In the example shown in fig. 1, the case where the single memory circuit 13 stores the programs corresponding to the respective processing functions has been described, but a configuration may be adopted in which a plurality of memory circuits are arranged in a distributed manner, and the processing circuit reads the corresponding programs from the single memory circuit.
In the above description, an example has been described in which the "processor" reads out and executes a program corresponding to each processing function from the memory circuit, but the embodiment is not limited to this. The expression "processor" means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (e.g., Simple Programmable Logic Device (SPLD)), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). In the case where the processor is, for example, a CPU, the processor reads out and executes a program stored in the storage circuit, thereby realizing each processing function. On the other hand, when the processor is an ASIC, the processing function is directly incorporated as a logic circuit in the circuit of the processor, instead of storing a program in a memory circuit. Note that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined to configure one processor and realize the processing function thereof. Furthermore, a plurality of components in fig. 1 may be integrated into one processor to realize the processing function.
Here, the program executed by the processor is provided by being incorporated in advance into a ROM (Read Only Memory), a Memory circuit, or the like. The program may be provided as a file in a form that can be installed in or executed by these apparatuses, and may be recorded on a computer-readable storage medium such as a CD (Compact Disk) -ROM, FD (Flexible Disk), CD-R (Recordable Disk), DVD (Digital Versatile Disk), or the like. The program may be stored in a computer connected to a network such as the internet, downloaded via the network, and provided or distributed. For example, the program is constituted by modules including the above-described functional units. As actual hardware, the CPU reads and executes a program from a storage medium such as a ROM to load each module on the main storage device, thereby generating each module on the main storage device.
According to the digital MR-RF coil of the present application, the ADC and the related digital data transmission circuit can be disposed in the vicinity of the analog feed point (analog feed point) without generating EMI. Further, multiple cable notches, filtering, and shadowing can be removed for each channel. This can reduce the weight of the coil and improve the efficiency of the work flow.
Furthermore, according to the digital MR-RF coil of the present application, it is possible to achieve electrical isolation between the digitizing circuit and the aggregation circuit within the coil, and to achieve lower cost data transmission in comparison with a digital RF coil having an optical fiber transmission line.
In view of the above, various modifications and variations can be made to the embodiments presented in this specification. Therefore, it is to be understood that the present disclosure may be practiced by methods other than those specifically recited in the claims.
According to at least one embodiment described above, an image artifact caused by EMI can be prevented.
Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various manners, and various omissions, substitutions, changes, and combinations of the embodiments can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.
Claims (9)
1. A high-frequency coil of a magnetic resonance imaging apparatus, comprising:
A channel aggregator which receives signals through a plurality of channels;
a data receiving unit that receives data from the high-frequency coil antenna for each of the channels; and
a non-conductive millimeter wave waveguide that transmits the data output from the data receiving unit to the channel aggregator for each of the channels,
the non-conductive millimeter wave waveguide has a millimeter wave transmitter, a millimeter wave receiver, and a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver.
2. The high-frequency coil according to claim 1,
the millimeter wave transmitter having a transmitter integrated circuit with an integrated millimeter wave transmitting antenna, the millimeter wave receiver having a receiver integrated circuit with an integrated millimeter wave receiving antenna,
the integrated millimeter wave transmitting antenna and the integrated millimeter wave receiving antenna are connected to the waveguide via a waveguide coupler.
3. The high-frequency coil according to claim 2,
the transmitter integrated circuit and the receiver integrated circuit comprise Complementary Metal Oxide Semiconductor (CMOS) devices.
4. The high-frequency coil according to claim 2,
the waveguide comprises a plastic material and is provided with a plurality of waveguides,
the waveguide coupler comprises plastic.
5. The high-frequency coil as set forth in claim 4,
the plastic comprises polytetrafluoroethylene, glass, acrylic, polycarbonate, or a polymer.
6. A magnetic resonance imaging apparatus is provided with a high-frequency coil having:
a channel aggregator which receives signals through a plurality of channels;
a data receiving unit that receives data from the high-frequency coil antenna for each of the channels; and
a non-conductive millimeter wave waveguide that transmits the data output from the data receiving unit to the channel aggregator for each of the channels,
the non-conductive millimeter wave waveguide has a millimeter wave transmitter, a millimeter wave receiver, and a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver.
7. The magnetic resonance imaging apparatus as set forth in claim 6,
an optical fiber for transmitting the data output from the channel aggregator is also provided.
8. The magnetic resonance imaging apparatus as set forth in claim 6,
a non-conductive millimeter wave waveguide is also provided for transmitting the data output from the channel aggregator.
9. A data transmission method applied to a high-frequency coil of a magnetic resonance imaging apparatus, comprising:
A data receiving unit that receives data from the high-frequency coil antenna through a plurality of channels and transmits the received data via the non-conductive millimeter wave waveguide for each of the channels; and
a channel aggregator receives data transmitted via the non-conductive millimeter wave waveguide for each of the channels,
the non-conductive millimeter wave waveguide has a millimeter wave transmitter, a millimeter wave receiver, and a waveguide connecting the millimeter wave transmitter and the millimeter wave receiver.
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US16/857,578 US11255934B2 (en) | 2020-04-24 | 2020-04-24 | MR RF coil with non-conductive waveguides |
US16/857,578 | 2020-04-24 | ||
JP2021042000A JP2021171636A (en) | 2020-04-24 | 2021-03-16 | High frequency coil, magnetic resonance imaging device, and data transfer method |
JP2021-042000 | 2021-03-16 |
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