IMAGE PROCESSING APPARATUS, MAGNETIC RESONANCE IMAGING APPARATUS, AND IMAGE PROCESSING SYSTEM

Abstract

To provide a coil element to be used in RF imaging on the basis of an optical image captured by an optical camera.SOLUTION: An image processing apparatus of an embodiment comprises first acquisition means and second acquisition means. The first acquisition means acquires an image including a coil. The second acquisition means acquires a disposition of the coil and a port connected with the coil, from the image.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The embodiments disclosed in this specification and the drawings relate to an image processing apparatus, a magnetic resonance imaging apparatus, and an image processing system. [Background technology]

[0002] A magnetic resonance imaging apparatus is an imaging device that excites the nuclear spins of a subject placed in a static magnetic field with a radio frequency (RF: Radio Frequency) signal at the Larmor frequency, and generates an image by reconstructing the magnetic resonance signals (MR (Magnetic Resonance) signals) generated from the subject in response to the excitation. Magnetic resonance imaging apparatuses can collect magnetic resonance signals from the subject non-invasively.

[0003] There is also a technology that uses images acquired by an optical camera in a system equipped with a magnetic resonance imaging device and an optical camera. This system can display an image showing the setting of an RF coil placed on or near the surface of a subject, and an image showing setting support information including the position of the virtual magnetic field center. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-039519 A Summary of the Invention [Problem to be solved by the invention]

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to determine the coil elements to be used in RF imaging based on an optical image captured by an optical camera. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0006] The image processing device according to the embodiment includes a first acquisition means and a second acquisition means. The first acquisition means acquires an image including a coil. The second acquisition means acquires the arrangement of the coil and the port to which the coil is connected from the image. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram showing an example of the overall configuration of an image processing system according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of the functions of the image processing system. [Diagram 3] FIG. 4A is an explanatory diagram showing an example of how arrangement information of coil elements of an RF coil is held, and FIG. [Figure 4] FIG. 2 is a diagram for explaining an example of the appearance of a coil element of an RF coil that is wrapped around a subject when used. [Diagram 5] FIG. 2 is an explanatory diagram showing an example of the configuration of an RF coil. [Figure 6] FIG. 1A is a diagram for explaining a first method for associating position information of an RF coil with a coil port to which an RF coil 20 is connected; FIG. 1B is a diagram for explaining a second method; and FIG. 1C is a diagram for explaining a third method. [Figure 7] FIG. 13 is an explanatory diagram showing an example of a confirmation image for checking whether the connection relationship between each coil and a coil port is correct. [Figure 8] 11 is a flowchart showing an example of a procedure for determining coil elements to be used in RF imaging based on an optical image captured by an optical camera when the optical image includes a plurality of RF coils. [Figure 9] 9 is a diagram for explaining coil elements to be used during MR imaging, which are determined by the procedure shown in FIG. 8 . [Figure 10] 1A and 1B are diagrams for explaining a first method for associating signals from multiple wireless coils with each coil on an optical image. [Figure 11]FIG. 13 is a diagram for explaining a second method for associating signals from multiple wireless coils with each coil on an optical image. [Figure 12] FIG. 11 is a diagram for explaining a third method for associating signals from multiple wireless coils with each coil on an optical image. [Figure 13] FIG. 2A is an explanatory diagram showing an example of a spine coil arranged on a bed top, and FIG. 2B is an explanatory diagram showing an example of a subject placed on the bed top on which the spine coil is arranged. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of an image processing apparatus, a magnetic resonance imaging apparatus, and an image processing system will be described in detail with reference to the drawings.

[0009] 1 is a block diagram showing an example of the overall configuration of an image processing system S according to an embodiment. The image processing system S according to the embodiment includes a magnetic resonance imaging (MRI) apparatus 1 and an optical camera 8. The magnetic resonance imaging apparatus 1 includes a magnet stand 100, a control cabinet 300, an image processing device (e.g., a console) 400, a bed 500, and the like.

[0010] The magnet gantry 100 and the bed 500 are usually arranged in a shielded room. On the other hand, the control cabinet 300 is arranged in a room called a machine room, for example, and the console 400 is arranged in an operation room.

[0011] The magnet gantry 100 has a static magnetic field magnet 10, a gradient magnetic field coil 11, a WB (Whole Body) coil 12, etc., and these components are stored in a cylindrical housing. The bed 500 has a bed body 50 and a bed top 51. The magnetic resonance imaging apparatus 1 has an RF coil 20 disposed close to the subject. In the following description, the RF coil 20 is described as one of the components of the magnetic resonance imaging apparatus 1, but the RF coil 20 may not be included in the configuration of the magnetic resonance imaging apparatus 1. In this case, although the RF coil 20 is not included in the configuration of the magnetic resonance imaging apparatus 1, the RF coil 20 and the magnetic resonance imaging apparatus 1 are configured to be connectable to each other. More specifically, the RF coil 20 and the bed top 51 of the magnetic resonance imaging apparatus 1 are configured to be connectable to each other.

[0012] The control cabinet 300 includes gradient magnetic field power supplies 31 (for the X-axis 31x, for the Y-axis 31y, and for the Z-axis 31z), an RF receiver 32, an RF transmitter 33, and a sequence controller .

[0013] The static magnetic field magnet 10 of the magnet gantry 100 has a roughly cylindrical shape and generates a static magnetic field in a bore (a space inside the cylinder of the static magnetic field magnet 10), which is an imaging region of a subject (e.g., a patient). The static magnetic field magnet 10 has a built-in superconducting coil, which is cooled to an extremely low temperature by liquid helium. In the excitation mode, the static magnetic field magnet 10 applies a current supplied from a static magnetic field power supply (not shown) to the superconducting coil to generate a static magnetic field, and then, when the mode is switched to the persistent current mode, the static magnetic field power supply is disconnected. Once the mode is switched to the persistent current mode, the static magnetic field magnet 10 continues to generate a large static magnetic field for a long time, for example, for more than one year. The static magnetic field magnet 10 may be configured as a permanent magnet.

[0014] The gradient magnetic field coil 11 also has a roughly cylindrical shape and is fixed inside the static magnetic field magnet 10. This gradient magnetic field coil 11 is composed of three gradient magnetic field coils for the X-axis, Y-axis, and Z-axis. When a gradient magnetic field current is supplied to each gradient magnetic field coil from a gradient magnetic field power supply (31x, 31y, 31z), a gradient magnetic field is generated in the X-axis, Y-axis, and Z-axis directions and applied to the subject.

[0015] The bed body 50 of the bed 500 can move the bed top 51 vertically and horizontally, and moves the subject placed on the bed top 51 to a predetermined height before imaging. Then, during imaging, the bed top 51 is moved horizontally to move the subject into the bore.

[0016] The WB coil 12 is fixed in a roughly cylindrical shape so as to surround the subject inside the gradient magnetic field coil 11. The WB coil 12 transmits RF pulses transmitted from an RF transmitter 33 toward the subject, and receives magnetic resonance signals (i.e., MR signals) emitted from the subject by excitation of hydrogen nuclei.

[0017] The RF coil 20 receives MR signals emitted from the subject at a position close to the subject. The RF coil 20 according to this embodiment includes a plurality of coil elements (coil components) 20EL. There are various types of RF coils 20, such as for the head, chest, spine, lower limbs, or whole body, depending on the imaging part of the subject. A plurality of RF coils 20 can be placed on the subject at the same time. FIG. 1 illustrates a state in which a chest RF coil (hereinafter referred to as a "chest coil") 20 is placed.

[0018] The RF transmitter 33 transmits an RF pulse to the WB coil 12 based on an instruction from the sequence controller 34. The coil selection circuit 36 ​​selects the MR signal received by the WB coil 12 or the MR signal received by the RF coil 20, and transmits it to the RF receiver 32. The RF receiver 32 detects the MR signal received by the WB coil 12 or the RF coil 20, and sends raw data obtained by digitizing the detected MR signal to the sequence controller 34.

[0019] The sequence controller 34, under the control of the console 400, drives the gradient magnetic field power supply 31, the RF transmitter 33, and the RF receiver 32 to scan the subject. Then, when the sequence controller 34 performs a scan and receives raw data from the RF receiver 32, it sends the raw data to the console 400.

[0020] The sequence controller 34 includes a processing circuit (not shown). The processing circuit is configured with hardware such as a processor that executes a predetermined program, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC).

[0021] The console 400 is configured as a computer having a processing circuit 40, a memory circuit 41, a display 42, and an input device 43. The console 400 is an example of an image processing device.

[0022] The memory circuitry 41 is a storage medium including a ROM (Read Only Memory), a RAM (Random Access Memory), and an external storage device such as a HDD (Hard Disk Drive) and an optical disk device. The memory circuitry 41 stores various information and data, and also stores various programs executed by a processor included in the processing circuitry 40. For example, the memory circuitry 41 stores a database that associates optical images of RF coils with arrangement information of a plurality of coil elements that the RF coils have, for various RF coils.

[0023] The display 42 is a display device such as a liquid crystal display panel, a plasma display panel, an organic EL panel, etc. The input device 43 is, for example, a mouse, a keyboard, a trackball, a touch panel, etc., and includes various devices for an operator to input various information and data.

[0024] The processing circuit 40 is a circuit including, for example, a CPU or a dedicated or general-purpose processor. The processor executes various programs stored in the memory circuit 41 to realize various functions described later. The processing circuit 40 may be configured with hardware such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). The various functions described later can also be realized by such hardware. The processing circuit 40 can also realize various functions by combining software processing by a processor and a program with hardware processing.

[0025] Using these components, the console 400 controls the entire magnetic resonance imaging apparatus 1. The processing circuitry 40 causes the sequence controller 34 to execute a scan based on the input imaging conditions, while reconstructing an image based on raw data input from the sequence controller 34, i.e., digitized MR signals. The reconstructed image is displayed on a display 42 or stored in a memory circuitry 41.

[0026] The optical camera 8 is installed, for example, on the ceiling of an imaging room in which the magnetic resonance imaging apparatus 1 is installed. The optical camera 8 includes a lens, an image sensor, an amplifier, an A / D (Analog to Digital) converter (not shown), and the like. The lens is an optical element for refracting and focusing light. The image sensor images the RF coil 20, which is the imaging target, via an objective optical system (not shown). The amplifier amplifies the output video signal from the image sensor. The A / D converter converts the analog video signal output from the amplifier into a digital signal. The optical camera 8 is connected to a processing circuit 40, and outputs the acquired image to the processing circuit 40 as a digital signal.

[0027] The optical camera 8 photographs all or a part of the bed top 51 from above before the bed enters the magnet gantry 100, and obtains an image of the RF coil 20 installed on the subject placed on the bed top 51. For example, the optical camera 8 can obtain a moving image as the image of the RF coil 20 by sequentially photographing at a predetermined frame rate.

[0028] The lens of the optical camera 8 may be a standard lens or a so-called wide-angle lens with a wider angle of view than a standard lens. The optical camera 8 is not limited to being installed on the ceiling, but may be fixed to a cover (including the inside of the bore) covering the magnet stand 100 or an end of the magnet stand 100, or may be attached to the magnet stand 100 or a wall around the magnet stand 100.

[0029] FIG. 2 is a block diagram showing an example of the functions of the image processing system S.

[0030] 2, the processing circuit 40 realizes a first acquisition function F1, a second acquisition function F2, a confirmation function F3, a decision function F4, and an image capture function F5 by reading and executing a computer program stored in the storage circuit 41 or directly incorporated in the processing circuit 40. Hereinafter, a case where the functions F1 to F5 function in a software manner by executing a computer program will be described as an example, but all or part of the functions F1 to F5 may be realized by a circuit such as an ASIC. In addition, the functions F1 to F4 may be provided in a computer, such as a tablet type computer, different from the console 400 having the image capture function F5.

[0031] The first acquiring function F1 includes a function of sequentially acquiring optical images including an RF coil 20 placed on a subject, for example, a chest coil placed on a subject placed on a bed top 51, by an optical camera 8. The first acquiring function F1 is an example of a first acquiring means.

[0032] The second acquisition function F2 includes a function for acquiring the arrangement of the RF coil 20 and the port to which the RF coil 20 is connected from the optical image acquired by the first acquisition function F1. The information on the arrangement of the RF coil 20 includes the position of the RF coil 20 with respect to the bed top 51 and the orientation of the RF coil with respect to the bed top 51. The second acquisition function F2 is an example of a second acquisition means.

[0033] The confirmation function F3 includes a function for confirming with the user via an image or a voice whether the ports to which each of the multiple RF coils acquired by the second acquisition function F2 is connected are correct ports immediately before the bed top 51 on which the subject is placed starts to move toward the center of the magnetic field. The confirmation function F3 is an example of a confirmation means.

[0034] The determination function F4 includes a function of determining a coil element to be used for RF imaging among the multiple coil elements 20EL of the RF coil 20 connected to the port acquired by the second acquisition function F2, based on the position of the RF coil 20 relative to the bed top 51, the orientation of the RF coil 20 relative to the bed top 51, and the positional relationship between the center of the magnetic field and the bed top 51. The determination function F4 is an example of a determination means.

[0035] The imaging function F5 includes a function for setting the positional relationship between the magnetic field center and the bed top 51 and the imaging range (Field Of View, hereinafter referred to as FOV) based on the imaging conditions, and a function for moving the bed top 51 on which the subject is placed to the magnetic field center so as to achieve the set positional relationship and performing MR imaging. The imaging function F5 is an example of an imaging means.

[0036] 3(a) is an explanatory diagram showing one example of how to hold arrangement information of the coil elements 20EL of the RF coil 20, and (b) is an explanatory diagram showing another example. Figures 3(a) and (b) show an example in which the RF coil 20 has 24 coil elements 20EL.

[0037] The processing circuit 40 of the console 400 in this embodiment determines where the coil element 20EL is located on the bed top 51 based on the optical image captured by the optical camera 8, and selects the appropriate coil element 20EL according to the imaging position for RF imaging.

[0038] Therefore, the processing circuit 40 not only detects the RF coil 20 from the optical image captured by the optical camera 8, but also grasps the arrangement positions of the coil elements 20EL based on the optical image. Therefore, it is preferable that the memory circuit 41 stores a database in which the optical image of the RF coil 20 is associated with the arrangement information of the multiple coil elements EL of the RF coil 20 for each of various RF coils 20 so that the RF coil 20 captured by the optical camera 8 can be expanded into the arrangement information of the coil elements 20EL (see FIGS. 3(a) and (b)).

[0039] FIG. 4 is a diagram for explaining an example of the appearance of the coil element 20EL of the RF coil 20 that is used by being wrapped around a subject.

[0040] The body coil and flex coil of the RF coil 20 are wound around the body of the subject when used. Therefore, the coil elements EL arranged in the radial direction are deformed. Therefore, it is difficult to predict the position of each coil element EL from the appearance of the RF coil 20.

[0041] On the other hand, in normal RF imaging, assuming that the RF coil 20 wound around the subject has a cylindrical shape, the selection of the coil elements EL to be used for RF imaging is segmented in the axial direction. Therefore, it is important to correctly deploy the axial element group whose shape of the RF coil 20 has not changed, and to be able to identify the position of the axial element group on the bed top 51 (see FIG. 4).

[0042] Therefore, for convenience in segmenting in the axial direction, it is better to classify each coil element 20EL by two-dimensional coordinates as shown in FIG. 3(a) rather than assigning an individual ID number to each coil element 20EL and classifying each coil element 20EL as 20EL(1), (2), ..., (24) as shown in FIG. 3(b).

[0043] In the following description, the coil elements 20EL are classified by two-dimensional coordinates as shown in Figure 3(a), and each coil element 20EL is referred to as 20EL ("row "column") using the row and column to which it belongs, and is represented as 20EL (1A), (1B), ..., (4E), and (4F).

[0044] FIG. 5 is an explanatory diagram showing an example of the configuration of the RF coil 20. As shown in FIG.

[0045] Generally, the RF coil 20 has a line-symmetric shape such as a rectangle or a cylinder. Therefore, the second acquisition function F2 of the processing circuit 40 according to the present embodiment grasps the orientation of the RF coil 20 based on structurally asymmetric feature points.

[0046] For example, when the RF coil 20 is a wired coil, the RF coil 20 has a cable 21 for connecting to a system, as shown in Fig. 5. In this case, the second acquisition function F2 can acquire the orientation of the RF coil 20 by using the outlet 22 of the cable 21 as a characteristic point. The second acquisition function F2 may also acquire the orientation of the RF coil 20 based on a label 23 or mark affixed to the RF coil 20, or other parts having a characteristic shape.

[0047] Furthermore, if the RF coil 20 is bent even more tightly and the type of RF coil 20 cannot be identified from the optical image, the second acquisition function F2 may determine the type of coil using coil type information output from the RF coil 20 when the RF coil 20 is connected to the system, and then deploy it at each element position.

[0048] Incidentally, when an optical image contains a plurality of RF coils 20, it is necessary to associate the position information of each RF coil 20 with information on which coil port of the bed top 51 each RF coil 20 is connected to.

[0049] As examples of a method for associating the position information of the RF coil 20 with the coil port to which the RF coil 20 is connected, three methods will be described.

[0050] 6(a) is a diagram for explaining a first method for associating position information of the RF coil 20 with the coil port to which the RF coil 20 is connected, (b) is a diagram for explaining a second method, and (c) is a diagram for explaining a third method. Figures 6(a), (b), and (c) show an example in which the optical image includes two RF coils 20, a first coil 201 and a second coil 202, and the bed top 51 has four coil ports, a first port 61, a second port 62, a third port 63, and a fourth port 64.

[0051] The first method is a method of detecting the routing of the cable 21. In the first method, the first acquisition function F1 acquires an image including the first coil 201 connected to the second port 62 via the cable 211 and the second coil 202 connected to the fourth port 64 via the cable 212 (see FIG. 6(a)). The second acquisition function F2 acquires information on the coil ports to which each coil is connected based on the positions of the cables 211 and 212 from the image acquired by the first acquisition function F1 for each of the first coil 201 and the second coil 202, thereby associating each coil with a coil port.

[0052] The second method is to detect the positions of both hands of the user (technician) when connecting the cable from an optical image. When connecting the cable 21 of the RF coil 20 to the coil port, the user generally supports the RF coil 20 with one hand to prevent the RF coil 20 from shifting, and connects the cable 21 to the coil port with the other hand (see FIG. 6(b)).

[0053] Therefore, the first acquisition function F1 may acquire optical images of the first coil 201 and the second coil 202 when the RF coils are connected to the coil ports via cables 211 and 212, respectively, triggered by the conduction of an electrical signal between the RF coil 20 and the system when the cable 21 is connected to the coil port, and associate each coil with the coil port by acquiring information about the coil port to which each coil is connected based on the positions of the user's hands depicted in the optical images.

[0054] The third method is a method of associating the RF coil 20 with the coil port closest to the RF coil 20. If the first or second method fails to associate each coil with a coil port, each coil may be associated with a coil port by acquiring the coil port closest to each coil as the port to which the coil is connected (see FIG. 6(c)).

[0055] Among these first to third methods, the accuracy of the association between each coil and the coil port is highest in the first method, followed by the second method, and lowest in the third method. On the other hand, the analysis capability required of the image processing software is highest in the first method, followed by the second method, and lowest in the third method.

[0056] Therefore, for example, if the analysis capability of the image processing software is insufficient to implement the first method, the second or third method may be used. Note that the second or third method includes the possibility of erroneous detection. Therefore, when using the second or third method, information on the coil port to which each coil is connected may be acquired again just before moving the bed top 51 to the center of the magnetic field after the coil setting is completed, in addition to the timing when the cable 21 is connected to the coil port.

[0057] FIG. 7 is an explanatory diagram showing an example of a confirmation image for checking whether or not the connection relationship between each coil and the coil port is correct.

[0058] The confirmation function F3 may confirm to the user whether or not the connection relationships between each coil and the coil port acquired by the second acquisition function F2 are correct immediately before moving the bed top 51 to the center of the magnetic field. Specifically, the confirmation function F3 may, for example, generate a confirmation image indicating whether or not the connection relationships between the coils and the coil ports are correct and display it on the display 42 or a monitor provided on the magnet gantry 100 (see FIG. 7), or may output a confirmation sound indicating whether or not the connection relationships between each coil and the coil port are correct to a speaker (not shown).

[0059] Fig. 8 is a flowchart showing an example of a procedure for determining coil elements to be used in RF imaging based on an optical image captured by the optical camera 8 when the optical image includes multiple RF coils 20. Fig. 9 is a diagram for explaining the coil elements 20EL to be used in MR imaging, which are determined by the procedure shown in Fig. 8.

[0060] First, in step ST11, a subject is placed on the bed top 51 of the bed 500. In step ST11, the subject is placed on the bed top 51 in the lowered position, and the bed top 51 on which the subject is placed is raised to adjust the height of the bed top 51.

[0061] Detection of the RF coil 20 may be triggered by detection based on the camera image that the subject has been placed on the bed top 51. Thereafter, the second acquisition function F2 may continue to detect the position and orientation of the RF coil 20 on the bed top 51 and the coil ports to which each coil is connected based on the optical image. In this case, the detection frequency may be determined based on the amount of calculation by the image processing software and the processing capacity of the system.

[0062] Next, in step ST12, two RF coils 20, the first coil 201 and the second coil 202, are placed on the subject placed on the bed top 51.

[0063] Next, in step ST13, the cable 211 of the first coil 201 is connected to the second port 62, for example.

[0064] The rough position and orientation of the RF coil 20 are determined when the cable 21 is connected to the coil port. Therefore, the rough position and orientation of the RF coil 20 and the coil port to which the coil 20 is connected may be provisionally determined at the timing when the cable 21 is connected to the coil port. In this case, the first acquisition function F1 is triggered by the connection of the cable 21 of the RF coil 20 to the coil port, and captures an optical image including a plurality of coils at the moment of connection (step ST14). Then, the second acquisition function F2 provisionally determines the position, orientation, and coil port connection destination of each coil. Specifically, the second acquisition function F2 acquires the arrangement (position and orientation) of each coil with respect to the bed top 51, and acquires information on the coil port to which each coil is connected by at least one of the above-mentioned first method, second method, and third method, thereby associating the position information of each coil with the coil port to which each coil is connected (step ST15).

[0065] When the second method is used, steps ST13-15 are repeated every time one RF coil 20 is connected to a port.

[0066] Next, in step ST16, each coil and the subject are fixed to the bed top 51 using a band or the like.

[0067] When each coil and the subject are fixed to the bed top 51, it is assumed that the final position and orientation of the RF coil 20 are determined. Therefore, the first acquisition function F1 captures an optical image immediately before moving the position of the bed top 51 corresponding to the imaging target position of the subject to the center of the magnetic field after each coil and the subject are fixed to the bed top 51 (step ST17). Then, the second acquisition function F2 finally determines the position, orientation, and coil port connection destination of each coil. Specifically, the second acquisition function F2 acquires the arrangement (position and orientation) of each coil relative to the bed top 51. In addition, by acquiring information on the coil port to which each coil is connected by at least one of the above-mentioned first method, second method, and third method, the position information of each coil is associated with the coil port to which each coil is connected (step ST18).

[0068] It is sufficient to execute either the provisional determination in steps ST14 and ST15 or the final determination in steps ST17 and ST18, and the other may be omitted. When the provisional determination in steps ST14 and ST15 is executed, the second method shown in FIG. 6(b) can be used. When the final determination in steps ST17 and ST18 is executed, a more final position and orientation of the RF coil 20 can be detected. Of course, both may be combined as shown in FIG. 8.

[0069] Next, in step ST19, the confirmation function F3 confirms with the user whether the connection relationship between each coil and the coil port acquired by the second acquisition function F2 is correct or not immediately before moving the bed top 51 to the center of the magnetic field (see FIG. 7). By confirming the connection relationship with the user, it is possible to prevent problems caused by erroneous detection of the connection destination port. Note that step ST19 may be omitted.

[0070] By performing the above steps ST11 to ST19, the position of each coil relative to the bed top 51, the orientation of each coil relative to the bed top 51, and the port to which each coil is connected can be obtained (see the left side of FIG. 9). Since the orientation of each coil relative to the bed top 51 has been obtained, the position of the coil element 20EL of each coil relative to the bed top 51 is also determined.

[0071] Therefore, in step ST20, the second acquisition function F2 associates the arrangement of the coil elements 20EL of each coil with the position of the bed top 51 based on the position, orientation, and connection port of each coil (see the center of FIG. 9). The position of each coil on the bed top 51 can be determined from the optical image, but the electrical signal of each coil element 20EL is determined by the coil port to which each coil 201, 202 is connected, so the result of associating each coil with the connection port is also added to the information on the coil element arrangement.

[0072] Next, the imaging function F5 acquires the FOV based on the imaging conditions (step ST21), and sets the positional relationship between the magnetic field center and the bed top 51 based on the imaging conditions (step ST22). Specifically, the imaging function F5 sets the longitudinal coordinate of the bed top 51 that will be located at the magnetic field center in MR imaging based on the imaging conditions.

[0073] Next, in step ST23, the determination function F4 determines the coil elements included in the FOV as the coil elements to be used for MR imaging based on the position of each coil relative to the bed top 51 and the orientation of each coil relative to the bed top 51, the longitudinal coordinates of the bed top 51 that will be located at the center of the magnetic field during MR imaging, and the FOV (see the right side of Figure 9).

[0074] Then, the imaging function F5 moves the bed top 51 on which the subject is placed to the center of the magnetic field so that the longitudinal position of the bed top 51, which will be located at the center of the magnetic field during MR imaging, is located at the center of the magnetic field (step ST24), and performs MR imaging (step ST25).

[0075] By the above procedure, even if a plurality of RF coils 20 are included in the optical image, the coil elements to be used in the RF imaging can be determined based on the optical image captured by the optical camera 8.

[0076] According to the processing circuitry 40 of this embodiment, even if the optical image includes a plurality of RF coils 20, it is possible to very simply, quickly and accurately determine the coil elements to be used in RF imaging based on the optical image captured by the optical camera 8. Therefore, it is possible to significantly shorten the examination time compared to a method that requires separate MR imaging to determine the coil elements to be used in RF imaging.

[0077] The processing circuit 40 according to the present embodiment is also suitable for cases where imaging is performed continuously at a plurality of imaging positions, such as when performing whole-body imaging. In cases such as whole-body imaging, the bed top 51 is moved and then MR imaging is repeated, so that a plurality of imaging positions are sequentially positioned at the magnetic field center, and MR imaging is performed at the FOV corresponding to each imaging position. Even in such a case, the arrangement of the coil elements 20EL of each coil is associated with the position of the bed top 51 (see the center of FIG. 9), so that the determination function F4 can easily and accurately determine the coil elements included in the FOV to be used for MR imaging, based on the positional relationship after the change and the FOV corresponding to the positional relationship after the change, every time the positional relationship between the magnetic field center and the bed top 51 is changed.

[0078] Incidentally, in the above embodiment, an example has been described in which the RF coil 20 is a wired coil that transmits an RF signal to the RF receiver 32 via the cable 21. If the RF coil 20 is a wireless coil that transmits an RF signal to the RF receiver 32 via wireless communication, the cable 21 and the coil port cannot be used.

[0079] When imaging is performed using multiple wireless coils, each coil included in the optical image and whose position and orientation on the bed top 51 is identified must be associated with the coil that is wirelessly transmitting an output signal to the system.

[0080] In this case, the second acquisition function F2 sequentially outputs signals to each of the multiple wireless coils to acquire the signals. Note that this signal does not need to be an RF signal. The second acquisition function F2 associates each of the multiple wireless coils that sequentially output signals with each coil that is included in the optical image and has identified its position and orientation on the bed top 51. For example, the second acquisition function F2 alternately outputs signals to the two wireless coils 201w in odd numbers and 202w in even numbers, and associates the wireless coil 201w that outputs signals in odd numbers with the coil on the head side on the optical image, and the wireless coil 202w that outputs signals in even numbers with the coil on the foot side on the optical image.

[0081] Three methods will be described as examples of a method for correlating the signals output from each of the multiple wireless coils with each coil as understood from an optical image.

[0082] FIG. 10 is a diagram for explaining a first method of associating signals from multiple wireless coils with each coil on an optical image, FIG. 11 is a diagram for explaining a second method, and FIG. 12 is a diagram for explaining a third method.

[0083] The first method is a method using a light emitting member such as an LED provided on the surface of each of the multiple wireless coils. In the first method, light emitting members 241, 242 are provided on the surface of each of the first wireless coil 201w and the second wireless coil 202w. The second acquisition function F2 may cause each of the multiple wireless coils to sequentially output a signal to acquire the signal, and may cause the light emitting member to emit light simultaneously with the output of the signal (see FIG. 10). In this case, the second acquisition function F2 may associate a wireless coil that is outputting a signal acquired at a certain timing with a wireless coil whose light emitting member emits light in the optical image at that timing.

[0084] The second method is to install a wireless access point AP for wireless communication between the wireless coil and the RF receiver 32 inside or near the optical camera 8. In the second method, the second acquisition function F2 causes each of the multiple wireless coils to sequentially output a signal, and associates the coil outputting the signal with one of the multiple wireless coils in the optical image based on the transfer times t1 and t2 required for the wireless access point AP built into the optical camera 8 that captures the optical image or provided near the optical camera 8 to receive the signal.

[0085] In the example shown in FIG. 11, the optical camera 8 calculates the distance from each of the wireless coils 201w, 202w to the wireless access point AP from the transfer time t1 required for data communication between the wireless access point AP and the wireless coil 201w and the transfer time t2 required for data communication between the wireless access point AP and the wireless coil 202w, determines the location of the wireless coil currently communicating based on the calculated distance, and provides the location of the wireless coil currently communicating with the system to the second acquisition function F2 of the processing circuit 40.

[0086] The third method is a method in which the optical camera 8 receives a transmission signal from the wireless coil. In the third method, the second acquisition means repeats the process of sequentially outputting a signal to each of the multiple wireless coils and acquiring the signal while moving the bed top 51, thereby associating the coil that output a signal with the multiple coils in the optical image based on a change in the transfer time required to receive the signal from each wireless coil.

[0087] In the third method, the optical camera 8 does not need to have a function for analyzing data of the transmission signal received from the wireless coil, and only needs to know the time when the signal was received. While the bed top 51 is being moved to the center of the magnetic field, each wireless coil transmits data to the optical camera 8 alternately at a predetermined time interval. The optical camera 8 receives the signal and keeps track of the current position of the bed top 51 and the time when the signal was received. The delay time until the optical camera 8 receives the signal varies depending on the position of the bed top 51. Therefore, it is possible to determine which position on the bed top 51 the signal is from by the change in the delay time of the signal received by the optical camera 8. Even if there are multiple wireless coils, it is possible to identify which coil's signal it is from by transferring data from each wireless coil in a fixed order. In addition, the transmission data (which may be a waveform) may be given a characteristic for each wireless coil, and the optical camera 8 may use the signal to identify the wireless coil.

[0088] Figure 13(a) is an explanatory diagram showing an example of a spine coil 20sp arranged on a bed top 51, and (b) is an explanatory diagram showing an example of a subject placed on the bed top 51 on which the spine coil 20sp is arranged.

[0089] The RF coil 20 according to this embodiment may be a coil, such as a spine coil 20sp, disposed between the bed top 51 and the subject. With this type of coil, it is difficult to grasp the entire subject in the optical image of the optical camera 8 once the subject is placed on the bed top 51, as shown in FIG. 13(b).

[0090] On the other hand, the position of a coil such as the spine coil 20sp once placed on the bed top 51 may be adjusted by the user even before the subject is placed on the bed top 51. Therefore, it is preferable to obtain the position and orientation of a coil such as the spine coil 20sp and the connection destination port of the cable 22sp using an optical image immediately before the subject is placed on the bed top 51, in which the entire coil is depicted.

[0091] Therefore, for example, when the spine coil 20sp is used, the first acquisition function F1 continues to acquire images including the spine coil 20sp sequentially at a predetermined frame rate from before the subject is placed on the bed top 51 (see FIG. 13(a)). When the subject is placed on the bed top 51, the second acquisition function F2 is provided with an image that is a frame before the subject is placed and is within a predetermined number of frames from the timing of the subject being placed. The second acquisition function F2 acquires the arrangement (position and orientation) of the spine coil 20sp relative to the bed top 51 and the port to which the spine coil 20sp is connected from the optical image received from the first acquisition function F1. Then, the second acquisition function F2 may associate the arrangement of the coil element 20EL of the spine coil 20sp with the position of the bed top 51 based on the position, orientation, and connection port of the spine coil 20sp.

[0092] According to at least one of the embodiments described above, the coil elements 20EL to be used in RF imaging can be determined based on the optical image captured by the optical camera 8.

[0093] In the above embodiment, the term "processor" refers to a circuit such as a dedicated or general-purpose CPU (Central Processing Unit), GPU (Graphics Processing Unit), or an Application Specific Integrated Circuit (ASIC), a programmable logic device (for example, a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). When the processor is a CPU, for example, the processor realizes various functions by reading and executing a program stored in a memory circuit. When the processor is an ASIC, for example, instead of storing a program in a memory circuit, a function corresponding to the program is directly built into the processor circuit as a logic circuit. In this case, the processor realizes various functions by hardware processing that reads and executes the program built into the circuit. Alternatively, the processor can realize various functions by combining software processing and hardware processing.

[0094] In the above embodiment, an example was shown in which a single processor of the processing circuit realizes each function, but a processing circuit may be configured by combining multiple independent processors, and each processor may realize each function. In addition, when multiple processors are provided, a memory circuit for storing a program may be provided for each processor, or one memory circuit may collectively store programs corresponding to the functions of all the processors.

[0095] Although some 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 various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0096] S Image Processing System 1. Magnetic resonance imaging equipment 8 Optical Camera 12 Coils 20 RF coil 20EL Coil Element 20sp Spine Coil 21, 211, 212 Cable 22 Drawer opening 23 Label 400 Console (Image Processing Device) 51 Bed Top 61 Port 1 62 Second Port 63 Third Port 64 4th Port 201w 1st wireless coil 202w 2nd wireless coil 21, 211, 212 Cable 241, 242 Illuminating member AP Wireless Access Point EL coil element F1 1st acquisition function F2 Second acquisition function F3 Confirmation Function F4 Confirmation function F5 Imaging function

Claims

1. A first acquisition means for acquiring an image including a coil having a plurality of coil elements; A second acquisition means for acquiring information on the arrangement of the coils and information on the orientation of the coils from the image; a determining means for determining at least one coil element to be used among the plurality of coil elements based on information on the arrangement of the coils and information on the orientation of the coils; An image processing device comprising:

2. The second acquisition means is As information on the arrangement of the coil, a position of the coil with respect to a tabletop is acquired, and as information on the orientation of the coil, information on the orientation of the coil with respect to the tabletop is acquired.

2. The image processing device according to claim 1.

3. an imaging means for setting a positional relationship between the center of the magnetic field and the top plate and an imaging range based on imaging conditions, and for performing MR imaging by moving the top plate on which a subject is placed to the center of the magnetic field so as to achieve the set positional relationship; Further equipped with The determining means is determining, as the coil element to be used, a coil element included in the imaging range among the plurality of coil elements, based on a position of the coil with respect to the tabletop, an orientation of the coil with respect to the tabletop, a positional relationship between the center of the magnetic field and the tabletop, and the imaging range; 2. The image processing device according to claim 1.

4. The imaging means is By repeating the movement of the tabletop and then the MR imaging, a plurality of imaging positions are sequentially positioned at the center of the magnetic field, and MR imaging is performed in an imaging range corresponding to each imaging position; The determining means is Each time a positional relationship between the center of the magnetic field and the tabletop is changed, a coil element included in the imaging range among the plurality of coil elements is determined as the coil element to be used based on the positional relationship after the change and the imaging range corresponding to the positional relationship after the change. The image processing device according to claim 3 .

5. The second acquisition means is acquiring an orientation of the coil with respect to a tabletop from the image based on at least one of a mark attached to the coil, a label attached to the coil, and a shape of the coil; 2. The image processing device according to claim 1.

6. The second acquisition means is and obtaining an orientation of the coil with respect to the tabletop from the image based on an outlet of a cable at the coil for connecting the coil to a port of the tabletop.

6. The image processing device according to claim 5.

7. The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements.

7. The image processing device according to claim 1,

8. The first acquisition means is acquiring an image including a plurality of said coils connected to said ports via cables; The second acquisition means is obtaining, for each of the plurality of coils, the port to which the coil is connected based on the position of the cable from the image; 8. The image processing device according to claim 7.

9. The first acquisition means is acquiring the image for each of the plurality of coils when the coil is connected to the port via a cable; The second acquisition means is For each of the plurality of coils, obtain the port to which the coil is connected based on the positions of both hands of the user connecting the coil to the port via the cable from the image.

9. The image processing device according to claim 7 or 8.

10. The first acquisition means is acquiring an image including a plurality of said coils connected to said ports via cables; The second acquisition means is For each of the plurality of coils, obtain from the image a port among the plurality of ports that is closest to the coil as a port to which the coil is connected; 10. The image processing device according to claim 7.

11. The first acquisition means is acquiring the image including the coil when the coil is connected to the port via a cable; The second acquisition means is When the image is acquired, the arrangement of the coils and the ports to which the coils are connected are acquired from the image.

11. The image processing device according to claim 7.

12. The first acquisition means is When the tabletop on which the subject is placed moves to the center of the magnetic field, the image including the coil is acquired immediately before the movement; The second acquisition means is When the image is acquired, the arrangement of the coil and the port to which the coil is connected are acquired again from the image. The image processing device according to claim 11.

13. a confirmation means for confirming with a user whether or not the ports to which each of the plurality of coils acquired by the second acquisition means is connected are correct ports immediately before the start of movement of a top board on which a subject is placed toward a magnetic field center; 13. The image processing device according to claim 7, further comprising:

14. Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, Each of the coils is provided with a light emitting member, The second acquisition means is By sequentially outputting a signal to each of the multiple coils to acquire the signal and simultaneously causing the light-emitting member to emit light, the coil outputting the acquired signal is associated with the coil among the multiple coils in the image in which the light-emitting member is emitting light.

14. The image processing device according to claim 7.

15. Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, The second acquisition means is A signal is sequentially output from each of the plurality of coils, and based on a transmission time required for a wireless access point built into an optical camera that captures the image or provided in the vicinity of the optical camera to receive the signal, the coil outputting the signal is associated with one of the plurality of coils in the image.

14. The image processing device according to claim 7.

16. Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, The second acquisition means is By repeatedly outputting a signal to each of the plurality of coils in sequence while moving the tabletop and acquiring the signal, the coil that output the signal is associated with the plurality of coils in the image based on a change in a transfer time required to receive the signal from each of the coils.

14. The image processing device according to claim 7.

17. the coil is a spine coil that is disposed on a tabletop before a subject is placed on the tabletop, The first acquisition means is acquire images including the spine coil at a predetermined frame rate in sequence from before the subject is placed on the top plate, and when the subject is placed on the top plate, provide the second acquisition means with images that are frames before the subject is placed on the top plate and are within a predetermined number of frames from the timing of the subject being placed on the top plate; The second acquisition means is acquiring the arrangement of the spine coil and the port to which the spine coil is connected from the image received from the first acquisition means; 17. An image processing apparatus according to claim 1.

18. A magnet stand; The image processing device according to any one of claims 1 to 17, A magnetic resonance imaging apparatus comprising:

19. an optical camera for acquiring the image by optical photography; The magnetic resonance imaging apparatus according to claim 18 ; An image processing system comprising:

20. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The second acquisition means is As information on the arrangement of the coil, a position of the coil with respect to a tabletop and an orientation of the coil with respect to the tabletop are obtained from the image; The second acquisition means further comprises: and / or obtaining an orientation of the coil relative to the tabletop from the image based on at least one of a mark attached to the coil, a label attached to the coil, and a shape of the coil; and From the image, an orientation of the coil with respect to the tabletop is obtained based on an outlet of a cable at the coil for connecting the coil to the port. Image processing device.

21. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements, The first acquisition means is acquiring the image for each of the plurality of coils when the coil is connected to the port via a cable; The second acquisition means is For each of the plurality of coils, obtain the port to which the coil is connected based on the positions of both hands of the user connecting the coil to the port via the cable from the image. Image processing device.

22. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements, The first acquisition means is acquiring an image including a plurality of said coils connected to said ports via cables; The second acquisition means is For each of the plurality of coils, obtain from the image a port among the plurality of ports that is closest to the coil as a port to which the coil is connected; Image processing device.

23. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements, Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, Each of the coils is provided with a light emitting member, The second acquisition means is By sequentially outputting a signal to each of the multiple coils to acquire the signal and simultaneously causing the light-emitting member to emit light, the coil outputting the acquired signal is associated with the coil among the multiple coils in the image in which the light-emitting member is emitting light. Image processing device.

24. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements, Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, The second acquisition means is A signal is sequentially output from each of the plurality of coils, and based on a transmission time required for a wireless access point built into an optical camera that captures the image or provided in the vicinity of the optical camera to receive the signal, the coil outputting the signal is associated with one of the plurality of coils in the image. Image processing device.

25. A first acquisition means for acquiring an image including the coil; A second acquisition means for acquiring the arrangement of the coils and the ports to which the coils are connected from the image; Equipped with The first acquisition means acquires an image including a plurality of the coils, The second acquisition means acquires, from the image, an arrangement of each of the plurality of coils and a port to which each of the plurality of coils is connected; Each of the plurality of coils has a plurality of coil elements, Each of the plurality of coils is a wireless RF coil that wirelessly outputs a received MR signal, The second acquisition means is By repeatedly outputting a signal to each of the plurality of coils in sequence while moving the tabletop and acquiring the signal, the coil that output the signal is associated with the plurality of coils in the image based on a change in a transfer time required to receive the signal from each of the coils. Image processing device.

Images