Magnetic resonance imaging device, magnetic resonance imaging support method, and magnetic resonance imaging support program

Abstract

To enable selection of a specific pad suitable for an inspection purpose of a subject on the basis of an optical image.SOLUTION: A magnetic resonance imaging device according to an embodiment includes a first acquisition unit and a selection unit. The first acquisition unit acquires an optical image obtained by imaging a subject. The selection unit selects one or a plurality of specific pads used for holding a body position of the subject from among a plurality of available pads, on the basis of the optical image.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The embodiments disclosed in this specification and the drawings relate to a magnetic resonance imaging apparatus, a magnetic resonance imaging assistance method, and a magnetic resonance imaging assistance program. [Background technology]

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

[0003] Furthermore, there is a technique for using an optical image acquired by an auxiliary optical camera to assist imaging in imaging by a magnetic resonance imaging apparatus.

[0004] In imaging using a magnetic resonance imaging apparatus, when imaging a subject such as a patient, a user such as a technician sets pads etc. when placing the subject on the bed top or fixing the examination area. Since the user sets pads etc. based on their own experience etc., there are cases where an appropriate pad is not selected due to differences in experience etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-40749 Summary of the Invention [Problem to be solved by the invention]

[0006] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to select a specific pad suitable for the inspection purpose based on an optical image. 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]

[0007] A magnetic resonance imaging apparatus according to an embodiment includes a first acquisition unit and a selection unit. The first acquisition unit acquires an optical image of a subject. The selection unit selects one or more specific pads to be used for maintaining the subject's posture from among a plurality of available pads based on the optical image. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of a magnetic resonance imaging apparatus according to an embodiment; [Diagram 2] FIG. 2 is a first diagram for explaining a flow of pad selection support in the magnetic resonance imaging apparatus according to the embodiment. [Diagram 3] FIG. 2 is a second diagram for explaining the flow of pad selection support in the magnetic resonance imaging apparatus according to the embodiment. [Figure 4] 5 is a flowchart showing an example of a first pad selection support operation in the magnetic resonance imaging apparatus according to the embodiment. [Diagram 5] 13A to 13C are diagrams for explaining gaps in the first pad selection support; [Figure 6] FIG. 4 is a view showing a first example of presentation of information on a specific pad selected in the magnetic resonance imaging apparatus according to the embodiment. [Figure 7] 6 is a flowchart showing an example of an operation of the second pad selection support in the magnetic resonance imaging apparatus according to the embodiment. [Figure 8] 13A to 13C are diagrams for explaining gaps in the second pad selection support; [Figure 9]10 is a flowchart showing an example of a third pad selection support operation in the magnetic resonance imaging apparatus according to the embodiment. [Figure 10] 13A to 13C are diagrams for explaining gaps in the third pad selection support. [Figure 11] 1A and 1B are diagrams for explaining the degree of bending of a subject's joint and its placement area. [Figure 12] 11 is a view showing a second example of presentation of information on a specific pad selected in the magnetic resonance imaging apparatus according to the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of a magnetic resonance imaging apparatus, a magnetic resonance imaging assistance method, and a magnetic resonance imaging assistance program will be described in detail with reference to the drawings.

[0010] (Overall configuration of magnetic resonance imaging device) 1 is a schematic diagram showing an example of the overall configuration of a magnetic resonance imaging (MRI) apparatus 1 according to an embodiment. The magnetic resonance imaging apparatus 1 includes a magnet stand 100, a control cabinet 300, a console 400, and a bed 500. The magnetic resonance imaging apparatus 1 further includes an optical camera 8.

[0011] The magnet gantry 100 and the bed 500 are arranged, for example, in a shielded room called an examination room. On the other hand, the control cabinet 300 is arranged, for example, in a machine room, and the console 400 is arranged, for example, in an operation room.

[0012] 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 housed 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 adjacent to a subject P (e.g., a patient). 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.

[0013] 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 .

[0014] 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 (the space inside the cylinder of the static magnetic field magnet 10), which is an imaging region of the subject P. 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 shifts to the persistent current mode, the static magnetic field power supply is disconnected. Once the mode shifts to the persistent current mode, the static magnetic field magnet 10 continues to generate a large static magnetic field for a long period of time, for example, for more than one year. The static magnetic field magnet 10 may be configured as a permanent magnet.

[0015] 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 31 (31x for the X-axis, 31y for the Y-axis, and 31z for the Z-axis), a gradient magnetic field is generated in the X-axis, Y-axis, and Z-axis directions and applied to the subject P.

[0016] The bed body 50 of the bed 500 can move the bed top 51 in the vertical and horizontal directions, and moves the subject P 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 P into the bore.

[0017] The WB coil 12 is fixed in a roughly cylindrical shape so as to surround the subject P inside the gradient magnetic field coil 11. The WB coil 12 transmits RF pulses transmitted from an RF transmitter 33 toward the subject P, while receiving magnetic resonance signals (i.e., MR signals) emitted from the subject P due to excitation of hydrogen nuclei.

[0018] The RF coil 20 receives MR signals emitted from the subject P at a position close to the subject P. There are various types of RF coils 20, such as for the head, neck, chest, spine, upper limbs, lower limbs, or whole body, depending on the part of the subject P to be examined. Fig. 1 shows an example in which the chest RF coil 20 is placed.

[0019] The RF transmitter 33 transmits an RF pulse to the WB coil 12 based on an instruction from the sequence controller 34. The RF receiver 32 detects an MR signal received by the WB coil 12 or the RF coil 20, and transmits data obtained by digitizing the detected MR signal (i.e., raw data) to the sequence controller 34.

[0020] 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 P. 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.

[0021] The sequence controller 34 includes a processing circuit (not shown). This 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).

[0022] The console 400 is configured as a computer having a processing circuit 40, a storage circuit 41, a display 42, and an input device 43. The console 400 is an example of an image processing device. In addition, a part or the whole of the console 400 may be realized by a computer different from the console 400, such as a tablet type computer.

[0023] 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. The memory circuitry 41 stores, for example, a database in which a plurality of RF coils 20 usable in the magnetic resonance imaging apparatus are registered. The memory circuitry 41 also stores, for example, pad registration information and the like.

[0024] 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.

[0025] The console 400 may further include a communication circuit 44. The communication circuit 44 includes an interface for performing communication connected to a network via a wired or wireless connection. The communication circuit 44 can, for example, exchange various types of data between the network and the memory circuit 41.

[0026] 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.

[0027] 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 MR image based on raw data, i.e., digitized MR signals, input from the sequence controller 34. The reconstructed MR image is displayed on a display 42 or stored in a memory circuitry 41.

[0028] 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, and the like, all of which are not shown. The lens is an optical element for refracting and focusing light. The image sensor captures an image of an object to be photographed via an objective optical system. 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 the captured optical image is output to the processing circuit 40 as a digital signal.

[0029] The optical camera 8 photographs all or a part of the bed top 51 from above before the subject P enters the magnetic gantry 100, and obtains an optical image including the examination site of the subject P placed on the bed top 51. For example, the optical camera 8 can obtain a moving image obtained by sequentially photographing at a predetermined frame rate as the optical image including the examination site of the subject P.

[0030] The magnetic resonance imaging apparatus 1 may also include a monitor 13 and a projector 9. The monitor 13 is provided in a place visible to a user in an examination room of the magnetic resonance imaging apparatus 1. The monitor 13 may be fixed to a cover that covers the magnet pedestal 100, or may be attached to the magnet pedestal 100 or a wall around the magnet pedestal 100. The monitor 13 is configured with a general display output device, such as a liquid crystal display or an OLED (Organic Light Emitting Diode) display. As shown in the screen display examples of FIG. 6 and FIG. 12, the selected specific pad is presented so that, for example, its setting position can be seen.

[0031] The projector 9 is configured by a display output device capable of projection, such as a liquid crystal projector, a video display system using a digital micromirror device, a reflective liquid crystal element projector, a laser projector, etc. The selected specific pad may be presented as a projection display on the bed top board 51 by the projector 9 so that the setting position can be known, for example. The selected specific pad and the setting position of the specific pad may be presented on the pad preparation shelf 7 on which the coils, pads, etc. are placed, or in a place nearby where advance preparation is performed.

[0032] The lens of the optical camera 8 may be a standard lens, or may be a so-called wide-angle lens having a wider angle of view than a standard lens. The optical camera 8 is not limited to being installed on the ceiling, and may be fixed to a cover that covers the magnetic stand 100. The optical camera 8 may be attached to a wall around the bed 500 (see FIG. 3(C)), or to a wall around the magnetic stand 100 (see FIG. 3(D)).

[0033] (Overview of Pad Selection Assistance) In imaging by a magnetic resonance imaging apparatus, after the purpose of the examination is determined, a user such as a technician sets pads when placing the subject P on the bed top 51 or fixing the examination site. In this case, the user sets them based on his / her own experience. The pad is a member placed between the subject P and the bed top 51 or between the subject P and the RF coil 20, and is a member for setting or fixing the subject P in a desired posture or position, or for setting or fixing the imaging site of the subject P and the RF coil 20 in a desired positional relationship during imaging. The pad includes a mat placed on the bed top 51 when the subject P is placed on the bed top 51, a pad for fixing the examination site of the subject P so that it does not move during imaging by the magnetic resonance imaging apparatus, and the like. The user selects a pad to be used, taking into consideration various information such as the purpose of imaging, the examination site, the pathological condition and posture of the subject P, and the degree of fixation. Therefore, depending on the user's skill and experience, a pad suitable for the purpose of testing the subject P may not be selected.

[0034] The pad selection support in the magnetic resonance imaging apparatus 1 according to the embodiment is performed to select a pad (i.e., a specific pad) suitable for the purpose of examining the subject P, regardless of the user's skill or experience. The pad includes a mat placed between the subject P and the bed top 51.

[0035] 1, the processing circuitry 40 of the magnetic resonance imaging apparatus 1 according to the embodiment realizes a first acquisition function F1, a second acquisition function F2, a selection function F3, an estimation function F4, a determination function F5, and a presentation function F6. Note that some or all of the above functions may be provided in a computer other than the console 400, such as a tablet computer.

[0036] Before describing in detail the configuration and operation of each of the above functions of the processing circuitry 40, an overview of the flow of pad selection support in the magnetic resonance imaging apparatus 1 will be given with reference to FIGS.

[0037] 2, the pad selection support in the magnetic resonance imaging apparatus 1 according to the embodiment can provide a first pad selection support, a second pad selection support, and a third pad selection support from when the purpose of the examination is determined (step ST1) until the setting of the specific pad is completed (step ST10). Note that in the pad selection support according to the embodiment, all or part of the first pad selection support, the second pad selection support, and the third pad selection support may be provided.

[0038] The first pad selection support corresponds to determining the purpose of the examination (step ST1), selecting the first specific pad (step ST2), and setting the first specific pad (step ST3). The second pad selection support corresponds to placing the subject P on the bed top (step ST4), selecting the second specific pad (step ST5), and setting the second specific pad (step ST6). The third pad selection support corresponds to completing the setting of the RF coil (step ST7), selecting the third specific pad (step ST8), and setting the third specific pad (step ST9). The first, second, and third specific pads are the specific pads selected in the first, second, and third pad selection support, respectively. Hereinafter, in the detailed description of each of the first, second, and third pad selection support, they are also simply referred to as specific pads.

[0039] 3 is a diagram for explaining the first pad selection support, the second pad selection support, and the third pad selection support. In the following, the examination site is described as the knee, and the RF coil 20 used for the examination is a knee coil, but the pad selection support of the embodiment is not limited by the type of RF coil 20, and can be performed with various types of RF coils 20 such as for the head, neck, chest, spine, upper limbs, lower limbs, or whole body.

[0040] As shown in Fig. 3(A), before the subject P is placed on the bed top during a medical interview or before entering an examination room, the posture of the subject P in an upright position is photographed by an optical camera. Then, based on the optical image of the subject P acquired in Fig. 3(A), a first pad selection assistance is performed. In the first pad selection assistance, a pad required before the subject P is placed on the bed top 51 is selected.

[0041] For example, when the knee coil 20 is used, a pad to be placed under the knee, a cushioning pad to be placed inside the knee coil 20, a large mat to be placed behind the back, etc. are selected. Fig. 3(B) shows a state in which pads A1, A2, A5, and A6 are selected as specific pads in the first pad selection assistance and set together with the lower side of the knee coil 20 (the lower half of the knee coil 20 which can be divided into an upper half and a lower half). In this way, in the first pad selection assistance, the RF coil 20 to be used and the mat and pad to be prepared in advance are selected based on disease information, the posture of the subject P in a standing position, etc.

[0042] Fig. 3(C) shows a state where the subject P is placed on the bed top 51 on which the pads of Fig. 3(B) have been set. Fig. 3(C) shows a state where there is a gap Y1 between the subject P and the pads A1 and A2. Also, it shows a state where there is a gap Y2 when the setting of the upper side of the knee coil 20 (the upper half of the knee coil 20 which can be divided into an upper half and a lower half) is completed on the subject P.

[0043] In order to select pads suitable for filling these gaps Y1 and Y2, a second pad selection assistance is performed. The second pad selection assistance is performed, for example, based on an optical image of the subject P placed on the bed top 51 captured by the optical camera 8. FIG. 3(D) shows a state in which pads A7 and A8 are further selected and set as specific pads in the second pad selection assistance. Pad A8 may be selected in the third pad selection assistance without being selected in the second pad selection assistance.

[0044] 3(D) shows that after the upper side of the knee coil 20 is set on the subject P, there is still a gap Z between the subject P and the pad A8. When a different type of RF coil 20, such as a knee coil 20 or a flex coil, is used, the specific pad suitable for the gap Z may differ. Also, the specific pad suitable for the gap Z may differ depending on the degree of bending of the joint of the subject P. In order to select the specific pad suitable for the gap Z, a third pad selection assistance is performed.

[0045] The pad selection support is performed in this manner, and the setting of the pads for the subject P is completed. The first pad selection support, the second pad selection support, and the third pad selection support will be described in detail below. In the flowcharts showing examples of the operation of the first pad selection support, the second pad selection support, and the third pad selection support below, the setting of a specific pad by the user is indicated by a dotted frame.

[0046] (First Pad Selection Assistance) 4 is a flowchart showing an example of an operation of the first pad selection support in the magnetic resonance imaging apparatus 1 according to the embodiment. The first pad selection support is performed following the determination of the examination purpose (step ST1).

[0047] In step ST10, the second acquisition function F2 acquires at least one of imaging-related information, such as RF coil information, disease information, and examination position, used in the examination of the subject P. In step ST1, when the examination purpose (e.g., disease information such as the name of the disease and pathological condition to be examined) is determined, the examination site is determined. In addition, RF coil information (e.g., the type and size of the RF coil 20) to be used for the examination site is determined based on the examination purpose and the body type of the subject P, such as the height and weight.

[0048] Then, the examination position of the subject P is determined based on the RF coil information and the disease information. Specifically, for example, if the subject P has a round back and a torn knee ligament, imaging is difficult with the subject's head on the tabletop, but the subject can be examined in a position where he or she lies on his or her back and has his or her head raised. Also, for example, if the subject P cannot bend his or her waist but can bend his or her knees, the subject can be examined in a position where the knees are bent and the feet are raised on a triangular mat. The imaging-related information is stored in, for example, the memory circuitry 41.

[0049] In step ST20, the first acquisition function F1 acquires an optical image of the subject P. For example, the posture of the subject P in an upright position is captured by an optical camera before the subject P is placed on the bed top during an interview or before entering an examination room. That is, the optical image capturing the posture of the subject P in an upright position is not limited to an optical image captured by the optical camera 8 installed in the magnetic resonance imaging apparatus 1, but may be an optical image captured by an optical camera installed in an interview room, a pre-examination room, or the like.

[0050] The posture of the subject P in the standing position differs depending on the subject P. As shown in Fig. 5(A), for example, the subject P may be able to stand upright. Also, as shown in Fig. 5(B), for example, the subject P may bend at the waist and change from an upright posture to a forward-leaning posture by α [°] (i.e., the gap between the subject P's head and the bed top 51 is X [mm]).

[0051] In step ST30, the determination function F5 determines whether the subject P can maintain a normal posture based on the optical image. Here, the normal posture is a posture that does not require a new specific pad in addition to the pad that is normally set according to the purpose of the examination. For example, when the normal posture is a posture in which the subject P is placed in a supine position parallel to the bed top 51 on which only a mat is set, the subject P who can maintain an upright posture as shown in FIG. 5(A) is determined to be able to maintain the normal posture. Also, for example, the subject P with a hunched back as shown in FIG. 5(B) is determined to be unable to maintain the normal posture because it is difficult for the subject P to maintain a supine position parallel to the bed top 51.

[0052] If it is determined in step ST30 that the subject P can maintain a normal posture (that is, YES), the process proceeds to step ST40. In step ST40, the selection function F3 does not select a new specific pad.

[0053] On the other hand, if it is determined in step ST30 that the subject P cannot maintain a normal posture (i.e., NO), the process proceeds to step ST50. Then, as described later, a selection function F3 selects a specific pad to be used to maintain the posture of the subject P.

[0054] In step ST50, the estimation function F4 estimates an arrangement area for arranging the pads based on the optical image. That is, in the first pad selection support, the estimation function F4 estimates the gap between the subject P and the bed top 51 as the arrangement area using the posture of the subject P in the standing position.

[0055] In step ST60, the selection function F3 acquires information on the provisional pad for which a determination is made in step ST70, which will be described later, from pad registration information on a plurality of pads that can be used in the magnetic resonance imaging apparatus 1.

[0056] Here, the pad registration information will be described. The pad registration information is a data table (for example, a pad list) for selecting one or more specific pads to be used to maintain the posture of the subject P. The pad registration information is composed of information on a plurality of pads, and is stored in advance in the storage circuitry 41, for example. In addition to the initially registered information, the user can also create new pad registration information by adding information on pads that are not initially registered, by inputting information via the input device 43, etc.

[0057] The pad registration information may include information on a plurality of pads owned by a facility such as a hospital in which the magnetic resonance imaging apparatus 1 is installed, depending on the model or options. If such information is included as the pad registration information, it becomes possible to select a specific pad that can actually be used in the facility in which the magnetic resonance imaging apparatus 1 is installed.

[0058] The pad registration information may also include information regarding the priority order for selecting a specific pad. If the determination for selecting a specific pad is made in the order of priority, it is not necessary to make a determination for all pads that can be selected as a specific pad, and the specific pad can be selected efficiently.

[0059] In addition, in a situation where multiple pads can be used, the priority order of pads may be changed for each subject or each examination site. For example, each RF coil may have information on the priority order suitable for the type of RF coil 20. Specifically, in the pad registration information for the knee coil, the pad with the highest priority order may be designated as a pad exclusively for the knee coil.

[0060] In addition, pad registration information may be provided for each medical condition. For example, depending on the medical condition, the pressure applied by the pad to the fixed portion may be adjusted. Even in such a case, it is possible to select a specific pad suitable for the examination contents. Additionally, information regarding the pads used by the subject P in past examinations may be used as pad registration information.

[0061] The pad registration information may include at least one of pad characteristic information of each of the multiple pads, among (a) outer dimensions, (b) deformation degree, and (c) softness. The pad characteristic information is used as information for selecting a pad suitable for the purpose of the inspection as a specific pad, as described below. Furthermore, the pad registration information may include information on priority order such that a specific pad is selected in order from the pad with the largest outer dimensions, or may include information on priority order such that a specific pad is selected in order from the pad with the softest dimensions.

[0062] Here, the external dimensions refer to the external shape of the pad, expressed by the shape, length, etc. of the pad, as shown by pad A1, pad A2, pad A3, and pad A4 in Fig. 5(C). Note that in Fig. 5(C), a rectangular parallelepiped and a triangular prism are shown as the pad shapes, but the shape of the pad is not limited thereto.

[0063] The degree of deformation and softness of the pads vary depending on the material, etc. The degree of deformation is the ratio of deformation of the pad to its outer dimensions. Instead of the degree of deformation, the dimensions to which the pad can be deformed from its outer dimensions may be used as characteristic information. The degree of deformation and softness can be used, for example, to determine whether the pad can be deformed to a degree that allows it to fit into a placement area (i.e., a gap) smaller than its outer dimensions.

[0064] In step ST70, the determination function F5 determines whether the temporary pad fits the placement area based on the optical image. In this determination, pad characteristic information may be used.

[0065] Specifically, whether or not the provisional pad fits into the placement area may be determined by comparing the estimated placement area dimensions (e.g., α [°] and X [mm] in Figure 5(B)) with the external dimensions of the pad obtained from the pad registration information (e.g., the lengths of each side of a rectangular prism, a [mm], b [mm], and c [mm] in Figure 5(C)). For example, if the external dimensions of the provisional pad are smaller than the dimensions of the placement area and the provisional pad can be set in the placement area, it is determined that the provisional pad fits into the placement area. In this case, it is preferable to select a pad that is as large as possible relative to the placement area.

[0066] Furthermore, the determination may be made based on the degree of deformation and softness of the pad. For example, if the outer dimensions of the temporary pad are larger than the dimensions of the placement area, but it can be deformed to fit into the placement area, it is determined that the pad fits the placement area. In this way, if it is determined that the pad fits the placement area in step ST70 (i.e., YES), the process proceeds to step ST80.

[0067] In step ST80, the selection function F3 selects the provisional pad determined to be suitable for the placement area as a specific pad. In this case, the selection function F3 may select the specific pad based on the pad registration information. As described above, the pad registration information may include pad characteristic information, information regarding priority, information regarding a plurality of pads that can be used in the magnetic resonance imaging apparatus 1, and the like.

[0068] In step ST90, the judgment function F5 judges whether or not the pads will be placed without gaps in the placement area based on the optical image of the subject P. If it is judged in step ST90 that the pads will be placed without gaps in the placement area (i.e., YES), the selection of the specific pad is completed. Specifically, in the first pad selection assistance, it is judged whether or not gaps are likely to occur in the placement area even after the selected specific pad is set based on the optical image of the subject taken in a standing position and the outer dimensions of the selected specific pad.

[0069] On the other hand, if it is determined in step ST90 that there is a gap in the placement area (i.e., NO), the process proceeds to step ST110. In step ST110, the estimation function F4 estimates the gap that will be created after the setting of the specific pad selected in step ST80 as a new placement area based on the optical image. In this case, the estimation may be performed using the optical image used in step ST20. After step ST110, the process returns to step ST60.

[0070] In step ST60 from the second time onwards, the determination function F5 acquires information on another pad from the pad registration information, which is different from the pad whose information was acquired in step ST60 up to the previous time.

[0071] Specifically, an example will be described in which the pad registration information including four pads in Fig. 5(C) has been prioritized in the order of pad A1, pad A2, pad A3, and pad A4. In this case, the information of pad A1, pad A2, pad A3, and pad A4 will be acquired as the information of the provisional pads in step ST60 for the first, second, third, and fourth times. Note that, although the external dimensions of pad A1, pad A2, pad A3, and pad A4 are different in Fig. 5(C), multiple pads of the same type may be included in the pad registration information.

[0072] Then, steps ST60 to ST90 are performed for the other pads from the second time onwards. When pad information is acquired based on the information regarding priority, the selection function F3 can select a specific pad from the pad registration information in order of priority.

[0073] Steps ST60 to ST90 are repeated until the selection of all the required specific pads is completed. In other words, the selection function F3 selects other pads as specific pads until an arrangement without gaps is achieved.

[0074] Now, we return to the explanation of step ST70. If it is determined in step ST70 that the pad does not fit the placement area (i.e., NO), the process also returns to step ST60. For example, if the outer dimensions of the pad are larger than the dimensions of the placement area and the pad cannot fit into the placement area even taking into account its degree of deformation and softness, it is determined that the pad does not fit into the placement area. When proceeding from step ST70 to step ST60, the pad has not been selected as a specific pad. In this respect, the process differs from the process proceeding from step ST110 to step ST60.

[0075] In this way, the selection function F3 selects a specific pad to be used to maintain the posture of the subject P. The selection function F3 also selects a specific pad from among a plurality of available pads based on the optical image and imaging-related information. The selection of a specific pad may be performed using the results of machine learning learned from the outer dimensions, degree of deformation, softness, etc. of each pad. The results of machine learning on the setting of a specific pad according to the purpose of the examination may also be presented as a recommended example.

[0076] In step ST100, the presentation function F6 presents to the user at least one piece of information on the selected specific pad and the position of the setting of the specific pad, using at least one of the monitor display and the projected display.

[0077] Fig. 6 is a diagram showing a first example of presentation of information on a specific pad selected in a magnetic resonance imaging apparatus according to an embodiment. In Fig. 6, information on the specific pad is displayed, for example, as a screen display example on the monitor 13 of the magnet gantry 100 and presented to a user. The back pad, head pad, in-coil pad, and foot pad in the screen display example of Fig. 6 correspond to pads A1, A2, A5, and A6, respectively, in the diagram of the magnetic resonance imaging apparatus 1. Moreover, the knee pad is omitted in the diagram of the magnetic resonance imaging apparatus 1.

[0078] Alternatively, information on a specific pad may be presented to the user by a projected display by the projector 9. The projected display by the projector 9 is performed, for example, on the bed top board 51. Furthermore, information on a specific pad may be presented to the user by lighting up a specific pad selected from among a plurality of pads placed on the pad preparation shelf 7.

[0079] In step ST120, the user performs settings for the specific pad that has been selected and presented.

[0080] According to the first pad selection support of the magnetic resonance imaging apparatus 1 according to the embodiment, even when a user with little skill or experience sets pads, the specific pad suitable for the examination content of the subject P can be selected from a plurality of available pads. Also, the specific pad suitable for the examination content can be prepared in advance before the subject P is placed on the bed top 51. Therefore, the burden on the subject P due to the posture and the degree of bending of the joints can be reduced.

[0081] (Second Pad Selection Assistance) 7 is a flowchart showing an example of an operation of the second pad selection support in the magnetic resonance imaging apparatus 1 according to the embodiment. The second pad selection support is performed after the subject P is placed on the bed top (step ST4 in FIG. 2).

[0082] In step ST210, the first acquisition function F1 acquires an optical image of the subject P. The optical image is an image of the posture of the subject P placed on the bed top 51 captured by the optical camera 8. In this respect, it differs from the first pad selection support in which an image of the subject P in an upright position is captured.

[0083] Even after the specific pads are set by the first pad selection assistance, a gap may be generated between the subject P actually placed on the bed top 51 and the specific pads. For example, Fig. 8 shows a state in which a gap of Y1 [mm] is generated between the subject P and the specific pads after pads A1, A2, A5, and A6 are set as specific pads by the first pad selection assistance.

[0084] Furthermore, there are cases where the gap between the subject P and the RF coil 20 can be estimated in advance before completing the setting of the RF coil 20. For example, it is shown that there is a gap of Y2 [mm] between the subject P and the RF coil 20 in order to set the upper side of the knee coil 20 after the lower side of the knee coil 20 has been set.

[0085] In step ST220, the estimation function F4 estimates a placement area for placing the pads based on the optical image. Here, the estimation function F4 estimates the placement area using the posture of the subject P placed on the bed top 51. In the second pad selection support, the gap between the subject P and the bed top 51, the gap between the subject P and the pads, etc. are estimated as the placement area.

[0086] Furthermore, before completing the setting of the RF coil 20, the estimation function F4 may further estimate the gap between the subject P and the RF coil 20 as the placement area based on the RF coil information. In this case, the placement area included in the area in which the RF coil 20 can be accommodated (for example, FIG. 11) can be estimated from the RF coil information such as the type and size of the RF coil 20. Note that, before completing the setting of the RF coil 20, the gap between the subject P and the RF coil 20 may not be estimated, but may be estimated in a third pad estimation support to be described later.

[0087] Steps ST230, ST240, and ST250 are not substantially different in function and action from steps ST60, ST70, and ST80 of the first pad selection support, respectively, and therefore duplicated explanations will be omitted. In step ST240 of the second pad selection support, if NO, the process returns to step ST230. Again, since the function and action are not substantially different from the case of returning from step ST70 to step ST60 of the first pad selection support, duplicated explanations will be omitted.

[0088] In the second pad selection support, after the specific pad is selected in step ST250, the process proceeds to step ST260, where at least one piece of information on the specific pad and the setting position of the specific pad is presented to the user. Step ST260 is substantially the same in function and action as step ST100 in the first pad selection support, and therefore a duplicated description will be omitted.

[0089] In step ST270, the user sets the specific pad that has been selected and presented. In the second pad selection support, when a specific pad is selected, information about the specific pad is presented from time to time, and the user sets the specific pad.

[0090] In step ST280, the first acquisition function F1 acquires an optical image of the subject P. The optical image is an image of the posture of the subject P placed on the bed top 51 captured by the optical camera 8. The optical image acquired in step ST280 is an optical image after the selected specific pad is set.

[0091] Step ST290 has substantially the same function and action as step ST90 in the first pad selection support, and therefore a duplicated description will be omitted. Specifically, in the second pad selection support, it is determined whether or not the selected specific pad is actually placed without gaps in the placement area after setting, based on an optical image of the subject P captured when the subject P is placed on the bed top 51.

[0092] In the second pad selection support, if the answer is NO in step ST290, the process returns to step ST220. In step ST220 from the second time onwards, the estimation function F4 estimates a gap that is created after the selected specific pad is set as a new placement area based on the optical image.

[0093] In addition, in step ST220, when the gap between the subject P and the RF coil 20 is estimated as the placement area based on the RF coil information, it is determined whether or not a gap is likely to occur within the placement area after setting the selected specific pad based on the optical image of the subject P taken when placed on the bed top 51 and the external dimensions of the selected specific pad.

[0094] In step ST230 for the second or subsequent times, the determination function F5 obtains information on other pads from the pad registration information, different from the pad whose information was obtained in step ST220 up to the previous time. Then, for the other pads for the second or subsequent times, steps ST230 to ST290 are performed, and this is repeated until selection of all the required specific pads is completed. In the second pad selection support, a new placement area is estimated in real time each time a specific pad is set.

[0095] According to the second pad selection assistance of the magnetic resonance imaging apparatus 1 according to the embodiment, the posture of the subject P is photographed at any time by the optical camera 8. Therefore, even if pad setting is required after the subject P is actually placed on the bed top 51, a user with little skill or experience can select a specific pad suitable for the examination contents of the subject P from among a plurality of available pads. In addition, the burden caused by the posture of the subject P and the degree of bending of the joints can be reduced.

[0096] (Third Pad Selection Assistance) 9 is a flowchart showing an example of an operation of the third pad selection support in the magnetic resonance imaging apparatus according to the embodiment. The third pad selection support is performed after the setting of the RF coil 20 is completed (step ST7 in FIG. 2).

[0097] In step ST310, the first acquisition function F1 acquires an optical image of the subject P. The optical image is an image of the posture of the subject P placed on the bed top 51 captured by the optical camera 8.

[0098] Even after a specific pad is set by at least one of the first pad selection assistance and the second pad selection assistance, a gap may be generated between the subject P placed on the bed top 51, the bed top 51, the specific pad, and the RF coil 20. For example, Fig. 10 shows a state in which a gap of Z [mm] is generated between the subject P and the RF coil 20 after pads A1, A2, A5, A6, A7, and A8 are set as specific pads by the first pad selection assistance and the second pad selection assistance.

[0099] In step ST320, the estimation function F4 estimates a placement area for placing the pads based on the optical image. Here, the estimation function F4 estimates the placement area based on the posture of the subject P placed on the bed top 51 as well as the degree of bending of the joints of the subject P. In the third pad selection support, the gap between the subject P and the bed top 51, the gap between the subject P and the pads, the gap between the subject P and the RF coil 20, etc. are estimated as the placement area.

[0100] Here, the degree of bending of the joints of the subject P and the placement area will be described with reference to Fig. 11. As shown in Fig. 11, the knee coil 20 has an accommodation area that can physically accommodate the examination site of the subject P. When placing the examination site in this accommodation area, the area of ​​the subject P that occupies the accommodation area varies depending on the body type of the subject P, the posture of the subject P, and if the examination site includes a joint, the degree of bending of the joint, etc.

[0101] 11 shows a state in which the knee joint of the subject P is bent and a state in which the knee joint is extended. Thus, the size and shape of the gap (i.e., the placement area) between the subject P and the RF coil 20 differs depending on the degree of bending of the subject P's joint. Furthermore, the specific pad that fills the placement area differs depending on the placement area. The estimation function F4 estimates the placement area that is included in the accommodation area of ​​the RF coil 20.

[0102] Steps ST320, ST330, ST340, ST350, ST360, ST370, ST380, and ST390 have substantially the same functions and operations as steps ST220, ST230, ST240, ST250, ST260, ST270, ST280, and ST290 of the first pad selection support, respectively, and therefore duplicated explanations will be omitted.

[0103] In the third pad selection assistance, in step ST390, specifically, based on an optical image of the subject P taken when placed on the bed top 51, it is determined whether or not the selected specific pad is actually placed without any gaps within the placement area after being set.

[0104] In step ST360, information about the specific pad is presented to the user. Fig. 12 is a diagram showing a second example of presentation of information about the specific pad selected in the magnetic resonance imaging apparatus according to the embodiment. In Fig. 12, the information about the specific pad is displayed, for example, as in a screen display example on the monitor 13 of the magnet gantry 100 and presented to the user. The in-coil pad (lower side), in-coil pad (upper side), and additional pad in the screen display example in Fig. 12 correspond to pads A5, A8, and A9 in the diagram of the magnetic resonance imaging apparatus 1, respectively.

[0105] In the screen display example of Fig. 6, information about the specific pad is presented in a top view of the bed top board 51 from the ceiling (Y-axis direction in Fig. 1). In contrast to this, in the screen display example of Fig. 12, information about the specific pad is presented in a cross-sectional view of the examination site of the subject P (Z-axis direction in Fig. 1). Note that the screen display of the information about the specific pad is not limited to this, and may be, for example, a cross-sectional view of the examination site of the subject P in the Y-axis direction in Fig. 1.

[0106] According to the third pad selection assistance of the magnetic resonance imaging apparatus 1 according to the embodiment, the posture of the subject P is photographed by the optical camera 8 at any time. Therefore, even if the pad setting is required after the RF coil 20 setting is completed, a user with little skill or experience can select a specific pad suitable for the examination contents of the subject P from among a plurality of available pads. In addition, the burden caused by the posture of the subject P and the degree of bending of the joints can be reduced. Furthermore, since the pads are fixed more appropriately, the deterioration of image quality caused by the movement of the examination part of the subject P during imaging can be reduced.

[0107] As described above, according to at least one embodiment of the magnetic resonance imaging apparatus, a specific pad suitable for an examination purpose can be selected based on an optical image.

[0108] In addition, the first acquisition function F1, the second acquisition function F2, the selection function F3, the estimation function F4, the determination function F5, and the presentation function F6 in the description of the embodiment are examples of the first acquisition unit, the second acquisition unit, the selection unit, the estimation unit, the determination unit, and the presentation unit in the claims, respectively. Also, the memory circuit 41 is an example of the memory unit in the claims.

[0109] 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 (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). When the processor is, for example, a CPU, the processor realizes various functions by reading and executing a program stored in a memory circuit. When the processor is, for example, an ASIC, instead of storing a program in a memory circuit, a function corresponding to the program is directly incorporated as a logic circuit in the processor circuit. In this case, the processor realizes various functions by hardware processing that reads and executes the program incorporated in the circuit. Alternatively, the processor can realize various functions by combining software processing and hardware processing.

[0110] 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.

[0111] Although some embodiments of the present invention 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, and modifications 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 described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0112] 1...magnetic resonance imaging device 7...pad preparation shelf 8...optical camera 9...projector 13...monitor 20...RF coil 40...processing circuit 41...memory circuit 51...bed top F1...first acquisition function F2...second acquisition function F3...selection function F4...estimation function F5...determination function F6...presentation function P...subject

Claims

1. A first acquisition unit that acquires an optical image of a subject; and a selection unit that selects, from among a plurality of available pads, one or more specific pads to be used for maintaining the posture of the subject based on the optical image. Magnetic resonance imaging device.

2. A second acquisition unit that acquires at least one imaging-related information of RF coil information, disease information, and an examination position used for the examination of the subject, the selection unit selects the specific pad to be used for maintaining the body position of the subject from among the plurality of usable pads based on the optical image and the imaging related information.

2. A magnetic resonance imaging apparatus according to claim 1.

3. a storage unit that stores pad registration information regarding the pads that can be used in the magnetic resonance imaging apparatus; The selection unit selects the specific pad from the pad registration information stored in a storage unit.

3. A magnetic resonance imaging apparatus according to claim 1.

4. The pad registration information includes at least one pad characteristic information of each of the plurality of pads, including (a) outer dimensions, (b) deformation degree, and (c) softness; the selection unit selects the specific pad from the pad registration information based on the pad characteristic information.

4. A magnetic resonance imaging apparatus according to claim 3.

5. the pad registration information includes information regarding a priority order for the selection unit to select the specific pad from the pad registration information, the selection unit selects the specific pad from the pad registration information in the order of priority based on the information regarding the priority.

4. A magnetic resonance imaging apparatus according to claim 3.

6. A determination unit, The determination unit determines whether the subject can maintain a normal posture based on the optical image, When the determining unit determines that the subject can maintain a normal posture, the selecting unit does not select the specific pad, When the determining unit determines that the subject cannot maintain a normal posture, the selecting unit selects the specific pad to be used for maintaining the posture of the subject.

3. A magnetic resonance imaging apparatus according to claim 1.

7. an estimation unit that estimates a placement area for placing pads based on the optical image, the estimation unit estimates the placement area using any one of (a) a posture of the subject in an upright position, (b) a posture of the subject placed on a bed top, and (c) a degree of bending of a joint of the subject; the selection unit selects the specific pad that can be placed within the estimated placement area.

3. A magnetic resonance imaging apparatus according to claim 1.

8. The estimation unit further estimates the placement region included in an area in which the RF coil can be accommodated, based on RF coil information.

8. A magnetic resonance imaging apparatus according to claim 7.

9. an estimation unit that estimates an arrangement area for arranging pads based on the optical image; A determination unit, the determining unit determines whether the specific pad is arranged without a gap within the arrangement area based on the optical image; When the determination unit determines that the specific pad is to be placed without any gap within the placement area, the selection unit selects the specific pad, When the determination unit determines that there is a gap in the placement area, the selection unit selects another pad different from the specific pad as the specific pad so that the placement area has no gap.

3. A magnetic resonance imaging apparatus according to claim 1.

10. A presentation unit that presents the information to a user, the presentation unit presents to a user at least one of information on the selected specific pad and a setting position of the specific pad, using at least one of a monitor display and a projected display; 3. A magnetic resonance imaging apparatus according to claim 1.

11. Acquire an optical image of the subject, selecting one or more specific pads to be used to position the subject from among a plurality of available pads based on the optical image; Magnetic resonance imaging assisted methods.

12. On the computer, acquiring an optical image of a subject; selecting one or more specific pads to be used to position the subject from among a plurality of available pads based on the optical image; A magnetic resonance imaging support program for performing the above.

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