CN111175680A

CN111175680A - Magnetic resonance system synchronization method and magnetic resonance system

Info

Publication number: CN111175680A
Application number: CN201811345082.8A
Authority: CN
Inventors: 季灵
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2018-11-13
Filing date: 2018-11-13
Publication date: 2020-05-19
Anticipated expiration: 2038-11-13
Also published as: CN111175680B

Abstract

The invention provides a synchronization method of a magnetic resonance system, wherein the magnetic resonance system comprises a system end and a plurality of receiving coils, and the method comprises the following steps: sending, by each of the plurality of receiving coils, a communication request to the system side, the communication request including a time t1 at which the receiving coil sent the communication request; transmitting, by the system side, a permission communication signal to the receiving coil, the permission communication signal including t1, a time t2 at which the system side receives the communication request, and a time t3 at which the system side transmits the permission communication signal; and calculating a time error with the system side by the coil according to t1, t2, t3 and the time t4 at which the permission communication signal is received.

Description

Magnetic resonance system synchronization method and magnetic resonance system

Technical Field

The invention mainly relates to the field of medical imaging, in particular to a magnetic resonance system and a synchronization method thereof.

Background

Magnetic Resonance Imaging (NMRI), also known as Spin Imaging (Spin Imaging), also known as MRI, uses the principle of Nuclear Magnetic Resonance to detect emitted electromagnetic waves by an external gradient Magnetic field according to different attenuations of the released energy in different structural environments inside a substance, and then draws a structural image inside the object.

In a magnetic resonance system, a superconducting magnet generates a uniform static magnetic field, a radio frequency transmitting coil excites hydrogen nuclei to spin to generate magnetic resonance signals, and a gradient coil is used for encoding spatial information of the signals. The magnetic resonance signals are collected by a radio frequency receiving coil, converted into digital signals through a receiving link, and finally reconstructed by a computer to obtain a magnetic resonance image.

The radio frequency receive coil is a very important component of the magnetic resonance system and has a decisive effect on the image quality of the magnetic resonance system. The array receiving coil is widely used at present and has the characteristics of high signal-to-noise ratio, flexible coverage range, convenient use and the like.

The existing coil uses radio frequency wires or optical fibers for transmission of radio frequency signals, and usually radio frequency cables are used as main components. However, the use of radio frequency cables has the following problems:

1) the use of cables complicates the scanning workflow and requires a patching operation of the coils. Especially in the case of receiving coils integrated in a moving patient bed, the cost of laying the cables is very expensive.

2) The use of a cable can affect patient safety by generating heat as it can sense magnetic resonance signals, and the patient's skin can be locally burned near the portion of the receiving antenna.

3) The use of the cable limits the density of the magnetic resonance coil unit, and for the magnetic resonance coil with wireless transmission, the density of the coil unit can be effectively improved according to requirements. Faster acceleration, etc. information has been provided.

In a magnetic resonance system, the system controls the gradients (Gx, Gy, Gz) and the radio frequency emission (RF) and needs to meet certain sequence timing requirements to obtain a correct excitation image.

In the conventional magnetic resonance receiving method, due to the fact that echo signals acquired by a plurality of receiving coils are asynchronous, phase deviation occurs, and artifacts of an image in a phase encoding direction are caused. Taking the timing chart of the spin echo as an example, fig. 1A and 1B illustrate the timing chart at one time TR (repetition time). The excitation signals of 90 ° and 180 ° are emitted by the RF in one TR, and the resulting Echo signal (Echo) is the signal that the receiving coil needs to receive. FIG. 1B magnifies the relationship between Echo and readout gradient (Gx), requiring that an inverse gradient be applied before applying Gx, when all spins are out of phase. While applying a positive gradient, all proton spins return to phase at the center of Echo, which ensures that the Echo centers of each TR are aligned, otherwise significant artifacts occur. Therefore, in order to improve the imaging quality of magnetic resonance, it is desirable to solve the problem of synchronization of echo signal acquisition.

Meanwhile, the acquisition of magnetic resonance has the application scene of a plurality of receiving coils. Aiming at such scenes, the realization of networking among a plurality of receiving coils, echo signal acquisition synchronization and other functions directly influences the quality of the multi-receiving coil combined imaging. Therefore, in a scenario of wireless transmission of magnetic resonance signals to a magnetic resonance system for multi-receiving coil combined imaging, it is desirable to solve the problem of multi-receiving coil echo signal networking.

Disclosure of Invention

In view of the above technical problem, the present invention provides a magnetic resonance system for wireless signal transmission of a multi-coil terminal. The magnetic resonance system includes a magnet, a gradient coil, a radio frequency transmit coil, and at least two radio frequency receive coils. The magnetic resonance system realizes wireless transmission of magnetic resonance signals of multiple receiving coils and solves the problem in wired analog magnetic resonance signal transmission.

In one aspect, a receiving coil for wireless transmission of magnetic resonance signals includes a coil unit, an analog-to-digital conversion module, a wireless transceiver module, a processor, and the like. The processor is used for communicating with a system end of the magnetic resonance system, receiving a reference signal transmitted by a main clock to carry out synchronous calibration of a local clock, controlling sampling of the analog-to-digital conversion module according to a sequence time sequence transmitted by the system end, and transmitting a sampled and digitized magnetic resonance signal to the system end. Meanwhile, the system end obtains information such as the type, the position, the time delay and the like of the target receiving coil according to the identification information transmitted by the processor.

According to an aspect of the present invention, there is provided a synchronization method of a magnetic resonance system including a system terminal and a plurality of receiving coils, the method including: sending, by each of the plurality of receiving coils, a communication request to the system side, the communication request including a time t1 at which the receiving coil sent the communication request; transmitting, by the system side, a permission communication signal to the receiving coil, the permission communication signal including t1, a time t2 at which the system side receives the communication request, and a time t3 at which the system side transmits the permission communication signal; and calculating a time error with the system side by the receiving coil according to t1, t2, t3 and the time t4 of receiving the permission communication signal.

According to another aspect of the present invention, there is provided a magnetic resonance system comprising: a system end; a plurality of receiving coils; the system end and the plurality of receive coils are configured to: sending, by each of the plurality of receiving coils, a communication request to the system side, the communication request including a time t1 at which the receiving coil sent the communication request; transmitting, by the system side, a permission communication signal to the receiving coil, the permission communication signal including t1, a time t2 at which the system side receives the communication request, and a time t3 at which the system side transmits the permission communication signal; and calculating a time error with the system side by the receiving coil according to t1, t2, t3 and the time t4 of receiving the permission communication signal.

Compared with the prior art, the invention provides a networking and synchronizing mode of a multi-coil terminal (namely, a receiving coil) aiming at an acquisition scene of the multi-receiving coil. Therefore, when the acquisition of the magnetic resonance signal faces the acquisition scene of a multi-coil terminal, the rear-end image can be correctly fused, and the image has no artifact, so that the wireless transmission of the magnetic resonance signal image is realized.

Drawings

FIGS. 1A and 1B are timing diagrams of spin echoes in the prior art.

Fig. 2A is a diagrammatic view of a medical imaging configuration within a scan room in accordance with aspects of the present invention.

Fig. 2B is a schematic structural diagram of a scanning device according to an embodiment of the present invention.

Fig. 3 is a diagram of a radio frequency receive coil in accordance with some aspects of the present invention.

Figure 4 illustrates the working mechanism of a magnetic resonance system according to the invention.

Figure 5 is a flow chart of a method of communication setup and synchronization control of a radio frequency receive coil and a system side of a magnetic resonance system according to some aspects of the present invention.

Fig. 6 illustrates a process of determining a timing error of a receiving coil with respect to a system side.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

Fig. 2A is a diagrammatic view of a medical imaging configuration within a scan room in accordance with an embodiment of the present disclosure. The medical imaging system 10 is located within the scan room 101 and the console 20 controlling the medical imaging system 10 is located outside the scan room 101. The medical imaging system 10 may include a scanning device 102, a scanning bed 103 disposed side-by-side (side-by-side) with the scanning device, the scanning device 102 for medically imaging a scanned object 104, and the scanning bed 103 for positioning the scanned object. The console 20 may include an input/output device 105 and a controller 106, among other things. The physician may control the position of the scanning bed 103 relative to the scanning device 102 via the console 20 outside the scanning booth 101, such as controlling the scanning bed 103 to be close to the scanning device 102 or controlling the scanning bed 103 to be far from the scanning device 102. Alternatively, the medical imaging system 10 may be an MR medical imaging system, and may also be a PET-MR, CT-MR, or other multi-modality medical imaging apparatus. In one embodiment, the medical imaging system 10 is an MR medical imaging system and the scanning device 102 is a dimensioned bore structure surrounded by superconducting magnets, gradient coils, or the like. In one embodiment, the scanning bed 103 may extend in a front-back direction and a left-right direction, the front-back direction being a longitudinal direction of the scanning bed 103 and corresponding to the first direction, and the left-right direction being a width direction of the scanning bed 103 and corresponding to the second direction, and the object 104 to be scanned may be placed on the surface of the scanning bed 103 to move along with the scanning bed 103 in the front-back direction or the left-right direction. The scanning device 102 may form a bore having a dimension that may be greater than or equal to the dimension of the scanning bed 103 in the width direction. In this embodiment, the second direction is perpendicular to an axial direction of the bore, and the first direction is the axial direction of the bore. Alternatively, the scanned object may be in a supine position, a left lateral position, a prone position, etc. on the scanning bed. In the present disclosure, the structures representing the support of the object to be scanned, such as the "scanning bed" and the "couch", "support table", "patient bed", "support bed", and "examination bed", may have the same meanings and may be replaced with each other. The "scanning device" and "scanner", "scanning system", "scanning apparatus", and "image scanning device", "image forming device" in the present disclosure may mean the same and may be replaced. The scanned object 104 may represent a human, animal, or water phantom, among other living or non-living objects. The first direction in the present disclosure is the "X" direction in the drawing, the second direction is the "Y" direction in the drawing, and the third direction is the "Z" direction in the drawing.

Input/output devices 105 may include a mouse, keyboard, joystick, trackball, display, and like human interaction devices. In one embodiment, the display may display the height, weight, age, imaging location of the scanned subject, and the operating state of the scanning device, among other things. The type of display 150 may be one or a combination of Cathode Ray Tube (CRT) display, Liquid Crystal Display (LCD), Organic Light Emitting Display (OLED), plasma display, etc.

The controller 106 may include one or more processors for receiving signals generated by the scanning device scanning the organ of the scanned object or operating state information of the scanning device and/or the scanning bed. A processing system may include a microcontroller, microprocessor, Reduced Instruction Set Computer (RISC), Application Specific Integrated Circuit (ASIC), application specific instruction set processor (ASIP), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Physical Processing Unit (PPU), microcontroller unit, Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), Programmable Logic Device (PLD), any circuit or processor capable of performing one or more functions, the like, or any combination thereof. The console 20 and the scanning bed 103, the console 20 and the scanning device 102, or the controller 106 and the scanning bed may communicate by connecting an optical fiber, a Local Area Network (LAN), a Wide Area Network (WAN), a Public Network, a private Network, a Public Switched Telephone Network (PSTN), the internet, a wireless Network, a virtual Network, or any combination thereof.

Optionally, the console 20 also includes one or more memory devices for storing various parameters such as data or information received from the scanning device 102, information from the scanning bed 103, and patient information entered by the physician via the input/output device 105, the scan protocol selected by the physician in accordance with the target organ to be scanned by the scanned subject 104, and so forth. The memory device may include a disk (disk), Random Access Memory (RAM), Read Only Memory (ROM), the like, or any combination thereof. The disk may be implemented by, for example, a magnetic disk, optical disk, floppy disk, optical disk, or zip disk. RAM may be implemented by, for example, Dynamic RAM (DRAM), double data rate synchronous dynamic RAM (DDR SDRAM), Static RAM (SRAM), thyristor RAM (T-RAM), and zero capacitor RAM (Z-RAM). ROM can be implemented, for example, as Masked ROM (MROM), Programmable ROM (PROM), erasable programmable ROM (PEROM), Electrically Erasable Programmable ROM (EEPROM), compact disk ROM (CD-ROM), and digital versatile disk ROM. In some embodiments, the memory device may store instructions issued by the physician via the input/output device 105 to move the scanning bed 103, by which the scanning bed 103 may be moved to the FOV area; the start-up scanning device 102 instruction sent via the input/output device 105 allows an imaging scan of the target organ in the FOV area. Alternatively, the target organ may be a tissue or a site of the patient/subject including the head, chest, lung, pleura, mediastinum, abdomen, large intestine, small intestine, bladder, gall bladder, triple energizer, pelvic cavity, diaphysis, limbs, skeleton, blood vessels, etc., or any combination thereof.

As shown in fig. 2B, which is a schematic structural diagram of the scanning device 102 provided in an embodiment of the present invention, the scanning device 102 includes a main magnet 201, a gradient coil 202 and a radio frequency coil. The inside portion of the main magnet 201, which is an annular cylindrical structure, forms a housing chamber 203 extending axially along the main magnet 201. The gradient coil 202 is mounted in the housing chamber 203 of the main magnet 201. The main magnet 201 may be a superconducting magnet, which includes a coil frame (not shown), a plurality of superconducting coils wound on the coil frame, and a housing (not shown) surrounding the coil frame. The main magnet 201 has a substantially cylindrical shape, and a housing chamber 203 extending in the axial direction is provided in a central region thereof.

The gradient coil 202 includes three sets of sub-gradient coils, which are respectively designated as Gx, Gy and Gz gradient coils. The gradient directions generated by the three groups of sub-gradient coil groups are mutually orthogonal in space, and are generally consistent with the horizontal direction, the vertical direction and the scanning bed head foot direction which are perpendicular to the scanning bed head foot direction of the magnetic resonance equipment in a space coordinate system, and are also consistent with the gradient directions of three logic axes in a pulse sequence. It can be understood that three groups of sub-gradient coils can operate independently, any two groups of coils can operate simultaneously, and three groups of coils can operate simultaneously, that is, the gradient magnetic field in any direction can be synthesized as required. It will be appreciated that the three sub-gradient coils of the gradient coil 202 are injection molded from a resin material or other insulating material to form a unitary structure that is substantially cylindrical and is adapted to fit within the receiving cavity 203 of the main magnet 201. The outer peripheral wall of the gradient coil 202 may be formed of an insulating material and is hermetically sealed and gas impermeable. The gradient coil 202 has an axially extending bore on the inside that defines a patient passageway for movement of the couch.

Radio frequency coils can be classified into body coils and local coils according to their functions. Alternatively, the kind of body coil or local coil may be a birdcage coil, a solenoid coil, a saddle coil, a Helmholtz coil, an array coil, a loop coil, or the like. In this embodiment, the main magnet surrounds to form an examination space, the gradient coils are arranged in the gaps formed by the main magnet, and the body coils are arranged inside the examination space, namely: the main magnet, the gradient coil and the body coil together form an accommodating cavity 203 extending along the first direction, a space included in the accommodating cavity 203 is a detection space, and a central portion of the accommodating cavity 203 may correspond to the FOV area. Alternatively, the local coil may be set as an array coil, and the array coil may be set in a 4-channel mode, an 8-channel mode, a 16-channel mode, a 24-channel mode, or a 32-channel mode. The local coil can be movably arranged on the surface of the scanning bed 103 or on the body of the scanned object 104. As shown in fig. 2A, a subject/patient as a scanned object 104 is carried on the scanning bed 103 along a first direction (a front-back direction of the scanned object), while a lower part of the body of the scanned object 104 has a spine coil for back scanning, and the scanned object 104 can move to the inside of the housing chamber 203 or be carried out of the housing chamber 203 along with the scanning bed 103. It should be noted that the "accommodating chamber" in the embodiments of the present disclosure may also be referred to as a "scanning chamber" or a "cavity".

It will be appreciated that in embodiments of the invention the radio frequency coil radio frequency receive coil is also referred to as a magnetic resonance termination, coil termination, receive coil, surface coil or receive coil array. The magnet, gradient coil, and radio frequency transmit coil may be collectively referred to as the system end of the magnetic resonance system.

Fig. 3 is a diagram of a radio frequency receive coil in accordance with some aspects of the present invention. The radio frequency receiving coil comprises a coil unit (1), an amplifier (2), a filter and analog-to-digital conversion module (3), a processor and a wireless transceiving module (4). The amplifier (2) is used for amplifying the magnetic resonance signals acquired by the coil unit (1) and improving the signal-to-noise ratio of the magnetic resonance signals. The filter is used for filtering the magnetic resonance signals and filtering out signals outside a frequency band; the analog-to-digital conversion module is used for converting the signal into a digital signal, and the digital signal is beneficial to improving the anti-interference performance of the signal so as to facilitate the subsequent processing.

The processor and the wireless transceiver module (4) can control the whole module through the FPGA, including processing the transceiver time sequence and controlling the acquisition and digitization of the magnetic resonance signals according to the system requirements. The wireless transceiver module is divided into an uplink and a downlink, wherein the uplink transmits the control signal and the synchronization information to the coil end by the magnetic resonance system, and the downlink transmits the magnetic resonance signal and the related information to the magnetic resonance system by the coil end. A synchronization confirmation procedure between the receive coil and the system side of the magnetic resonance system is required before the uplink and downlink are established, which is described in further detail below.

Figure 4 illustrates the operating mechanism of the magnetic resonance system.

As shown in fig. 4, the magnetic resonance system includes a plurality of receiving coils which communicate with the magnetic resonance system side through a channel. Each receiving coil is equivalent to a data acquisition point, and a plurality of data acquisition points are networked to form a network for communication. Since the coil and the magnetic resonance system (system side) are wirelessly transmitted, the magnetic resonance system side and the receiving coil can form a multiple access communication system. In the system, each receiving coil transmits a signal to the magnetic resonance system side through a common channel. Since magnetic resonance systems have high requirements for signal synchronization, the multiple access method typically utilizes frequency division multiple access and code division multiple access. The frequency division multiple access technique is inefficient because it only occupies the channel when the coil is used, which may result in a limitation of the transmission rate or the number of coil terminals that are simultaneously accessed. While the cdma technique uses direct sequence spread spectrum to achieve a channel sharing by multiple receive coils, where each coil terminal is assigned a unique signature sequence, allowing the signal to be spread over the entire frequency band.

Optionally, the system end in the present invention may transmit power to a plurality of receiving coils by using wireless power transmission. In one embodiment, considering that the distance between the transmitting coil and the receiving coil at the system end is short in the detection process, when current passes through the transmitting coil, the generated magnetic flux forms induced electromotive force in the corresponding receiving coil, so that electric energy is transmitted to the receiving coil. In another embodiment, the system end can also supply power to the receiving coil by means of microwave wireless power transmission.

Figure 5 illustrates a radio frequency receive coil and system-side communication setup and synchronization control methodology of a magnetic resonance system in accordance with aspects of the present invention. Specifically, the method comprises the following steps:

in step 501, the radio frequency receiving coil 1 may send a communication request to the system side.

Specifically, a plurality of radio frequency receiving coils are placed in the magnetic resonance system to start working, each radio frequency receiving coil monitors/monitors the transmission condition on the channel between the radio frequency receiving coil and the system end, and when the channel is found to be idle, the radio frequency receiving coil can send a communication request to the system end.

The communication request may include at least coil characteristic information and time information associated with transmitting the communication request. The coil characteristic information may include the type of coil (including but not limited to head coil, abdomen coil, knee coil, etc.), the frequency band to which the coil belongs, and a characteristic code obtained in frequency division or code division. The time information may include the time t1 at which the coil sent the communication request.

Step 502, the system end receives a communication request from the radio frequency receiving coil 1 and records the time t2 when the communication request is received; it is then determined whether the channel is blocked.

If the system end determines/feeds back that the channel is not blocked, the system end identifies the coil characteristics according to the communication request, and allocates resources to the radio frequency receiving coil 1 according to the frequency band (in the case of using frequency division multiple access) or the characteristic sequence (in the case of using code division multiple access) to which the coil belongs, wherein t1, the time t2 of receiving the communication request and the time t3 of sending the permission communication signal are included in the permission communication signal.

If the system side determines that the channel is blocked (e.g., occupied), a blocking signal is sent to the corresponding coil terminal, and returns to step 501.

In step 503, the system side sends a communication permission signal to the radio frequency receiving coil 1 on the allocated communication resource.

In step 504, the radio frequency receiving coil 1 receives the permission communication signal, records the time t4 when the permission communication signal is received, and determines the timing error of the coil relative to the system end, thereby calibrating the timing of the radio frequency receiving coil 1.

Steps 505-508 are used for synchronization of coil 2, which is similar to steps 501-504 described above for coil 1.

Steps 505-508 show the process of synchronizing the radio frequency receive coil 2 to the system, which is the same as steps 501-504 and will not be described again.

Although only two coils are shown synchronized in fig. 5, those skilled in the art will appreciate that the synchronization process may be applied to many more coils. Additionally, although steps 505-508 shown in FIG. 5 are performed after steps 501-504, one skilled in the art will appreciate that the synchronization of coil 1 and coil 2 may also be performed concurrently.

By completing the synchronization of each coil in the magnetic resonance system, the networking and synchronization of a plurality of coils in the system are realized, thereby improving the quality of multi-coil combined imaging.

Specifically, as shown in fig. 6, t1 is the time when the receiving coil transmits the communication request, t2 is the time when the system side receives the communication request, t3 is the time when the system side transmits the permission communication signal, and t4 is the time when the receiving coil receives the permission communication signal.

The transmission delay of the round-trip link between the receiving coil and the system end is:

Delay＝(t4-t1)-(t3-t2)

assuming that the back-and-forth network link is symmetrical, i.e. the transmission delay from the receiving coil to the system segment and from the system segment to the receiving coil are equal, the timing Error of the receiving coil relative to the system end can be calculated as:

Error＝t2-t1-Delay/2＝((t2-t1)+(t3-t4))/2

the receiving coil uses the timing Error to adjust the timing of the receiving coil, and the timing synchronization with the system end can be completed. In one example, the synchronization process may be performed again at the beginning of a coil position change and a rescan. In another example, when the synchronization confirmation procedure is very fast, the synchronization procedure may also be performed once in each TR.

After timing synchronization, the receiving coil can synchronously acquire magnetic resonance signals according to the sequence time sequence distributed by the system and the time delay obtained by the communication establishment time, and the acquired digital signals are transmitted to the system end for image fusion.

In another embodiment, each coil terminal can also calculate the delay of the local coil time and the system reference time according to the time difference with the system. Correspondingly, in the acquisition of the magnetic resonance signals, the time delay is written into the digitized magnetic resonance signals and is transmitted to the system end for magnetic resonance image reconstruction, and the system end can align the echo signals acquired by TR each time according to the obtained time delay.

The various operations of the methods described above may be performed by any suitable means capable of performing the operations, such as various hardware and/or software components, circuits, and/or modules. In general, any of the operations illustrated in the figures may be performed by corresponding functional means capable of performing the operations.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a field programmable gate array signal (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

In one or more aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk (disk) and disc (disc), as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks (disks) usually reproduce data magnetically, while discs (discs) reproduce data optically with lasers. Thus, in some aspects, computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). Additionally, in some aspects, the computer readable medium may comprise a transitory computer readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.

Claims

1. A method of synchronization of a magnetic resonance system comprising a system end and a plurality of receive coils, the method comprising:

sending, by each of the plurality of receiving coils, a communication request to the system side, the communication request including a time t1 at which the receiving coil sent the communication request;

transmitting, by the system side, a permission communication signal to the receiving coil, the permission communication signal including t1, a time t2 at which the system side receives the communication request, and a time t3 at which the system side transmits the permission communication signal; and

the time error with the system side is calculated by the receiving coil according to t1, t2, t3 and the time t4 at which the permission communication signal is received.

2. The method of claim 1, further comprising:

after receiving a communication request from the receiving coil, the system end allocates communication resources to the receiving coil according to coil characteristics included in the communication request; and

and the system end sends the communication permission signal to the receiving coil on the allocated communication resource.

3. The method of claim 1, further comprising:

each of the plurality of receiving coils adjusts timing using its time error with the system side so that the plurality of receiving coils are synchronized.

4. The method of claim 1, wherein the calculating the time error with the system side comprises:

the time error is ((t2-t1) + (t3-t 4))/2.

5. The method of claim 1, wherein the system side and the plurality of receive coils communicate using code division multiple access or frequency division multiple access.

6. A magnetic resonance system comprising:

a system end;

a plurality of receiving coils;

the system end and the plurality of receive coils are configured to:

sending, by each of the plurality of receiving coils, a communication request to the system side,

the communication request includes a time t1 at which the receiving coil transmits the communication request;

7. The magnetic resonance system of claim 6, wherein the system side is further configured to:

after receiving a communication request from the receiving coil, allocating communication resources to the receiving coil according to coil characteristics included in the communication request; and

the permission communication signal is transmitted to the receiving coil on the allocated communication resource.

8. The magnetic resonance system of claim 6, further comprising:

9. The MR system of claim 6, wherein the calculating the time error from the system-side comprises:

the time error is ((t2-t1) + (t3-t 4))/2.

10. The system-side of claim 6, wherein the system-side and the plurality of receive coils communicate using code division multiple access or frequency division multiple access.