Imaging support device, magnetic resonance imaging device equipped with the imaging support device, and imaging support method

Abstract

To provide an imaging support technology capable of checking safety when setting a subject while securing image quality in imaging.SOLUTION: A camera image of a subject placed on a table for conveying the subject of an imaging device is acquired and an optimum arrangement of an instrument mounted on the subject is presented from the viewpoint of the image quality using the camera image. Then, safety is determined / predicted on whether or not there is a collision or an entrainment of the mounted instrument, etc. and a structure such as the imaging device, and whether or not a bore and a clearance can be kept even after the mounting using the camera image of the subject mounted with the instrument, and the result is presented to an operator.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an apparatus for supporting the setting of a subject in an imaging space in an imaging apparatus such as a magnetic resonance imaging (MRI) apparatus, and more particularly to a setting support technique including the attachment of a receiving coil. [Background technology]

[0002] In an examination using an MRI device, a receiving coil for receiving a nuclear magnetic resonance signal is attached to the examination site of the subject, and the examination site of the subject is placed in an imaging space where a static magnetic field is generated, and imaging is performed. In order to obtain good images, it is important that the receiving coil is appropriately attached to the appropriate position of the subject, and that the examination site is reliably positioned almost at the center of the static magnetic field. In addition, the imaging space is formed in a relatively narrow bore, and the subject with the receiving coil attached is transported into the narrow bore while lying on the bed, so it is important to ensure a safe transportation operation. In other words, it is necessary to proceed with the operation so that there are no accidents such as the receiving coil attached to the subject or its cable getting caught on other structures during transportation, or the subject hitting the entrance or inner wall of the bore, which causes the subject to fall from the designated position on the bed.

[0003] Various proposals have been made to appropriately set up the receiving coil from its attachment to the magnetic field space. For example, Patent Document 1 discloses a technology that analyzes the movements of the subject, the equipment used for imaging (such as the receiving coil), the operator, etc. from images acquired by a camera, and monitors whether a series of operations (workflow) is proceeding appropriately, and teaches how to determine the appropriateness of safety in at least one state and issue a warning.

[0004] Patent document 2 also proposes acquiring 3D image data of a subject positioned on a bed device, obtaining information about the subject from changes in the 3D image data over time, such as information about whether the subject or an accessory unit attached to the subject (such as a receiving coil) is protruding from the bed device, comparing this with a safety value, and outputting the result.

[0005] Furthermore, Patent Document 3 proposes a system that calculates the difference between an artificial image generated using a generator neural network and optical imaging data, and judges abnormal events that occur during setup using AI and issues a warning. Abnormal events include improper placement or connection of coils, and the occurrence of cable loops or body loops that can be sources of induced current. Patent Document 4 further proposes a technology specialized in detecting loops during transportation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-183525 A [Patent Document 2] JP 2013-248402 A [Patent Document 3] Special Publication No. 2022-508337 [Patent Document 4] JP 2022-124633 A Summary of the Invention [Problem to be solved by the invention]

[0007] In one example of the setup process from attaching the receiving coil to transporting it into the magnetic field space, particularly important items are that the receiving coil is attached in the optimal position on the subject to obtain good image quality, and that safety is ensured when the subject is transported in that state.

[0008] Conventional technology monitors the state of a subject with a receiving coil attached during transportation and detects abnormalities on an AI or rule basis, but does not determine the safety of subsequent work at the point when the receiving coil is attached. In other words, conventional technology can detect abnormal events or inconveniences that occur during the transportation work and deal with them, but when it becomes necessary to deal with them, it takes time to deal with them, for example, by returning the subject to the state before transportation and reattaching the receiving coil, which is an obstacle to work efficiency. In addition, the point of optimally attaching the receiving coil and using it under optimal conditions from the viewpoint of image quality as well as safety is not taken into consideration.

[0009] The present invention provides a technique for determining the safety of a subject during patient setting work while ensuring image quality, and for an operator to avoid work that cannot ensure safety. [Means for solving the problem]

[0010] In order to solve the above problem, the position of the receiving coil is displayed for the subject before the receiving coil is attached, and a camera image of the subject after the receiving coil is attached is acquired, and the acquired camera image is used to judge safety and the result is displayed. In other words, the imaging support device of the present invention is an imaging support device that supports the work of setting a subject in an imaging device that has an imaging space and a table on which the subject is placed and transported to the imaging space, and is equipped with a camera image acquisition unit that acquires a camera image of the subject placed on the table, an optimal placement presentation unit that uses the camera image to present the optimal placement of an instrument to be attached to the subject, and a judgment unit that judges the safety of the setting work using the camera image of the subject with the instrument attached.

[0011] The result of the determination by the determination unit is presented to the operator or is fed back to the optimum layout presentation unit.

[0012] The magnetic resonance imaging apparatus of the present invention has the function of the imaging support device described above as a function of the calculation unit.

[0013] In addition, the imaging support method of the present invention is a method for supporting the task of setting a subject in an imaging device having an imaging space and a table on which the subject is placed and on which the subject is transported to the imaging space, and includes a camera image acquisition step of acquiring a camera image of the subject placed on the table, an optimal placement presentation step of using the camera image to present an optimal placement of an instrument to be attached to the subject, a determination step of determining the safety of the setting task using the camera image of the subject with the instrument attached, and a result presentation step of presenting the determination result of the determination step. Effect of the Invention

[0014] According to the present invention, by arranging the receiving coil and the cables connected thereto at the optimal position relative to the subject, the subject can be transported and positioned within the magnetic field space while ensuring the image quality of the image and ensuring safety. This allows the transport operation to be performed without interruption, improving the efficiency of the operation as well as the safety of the operation. [Brief description of the drawings]

[0015] [Figure 1A] 1 is a diagram showing an example of the appearance of an imaging device to which the present invention is applied; [Figure 1B] FIG. 13 is a diagram showing another example of the appearance of an imaging device to which the present invention is applied. [Diagram 2] Block diagram of the imaging device (MRI). [Diagram 3] FIG. 2 is a functional block diagram of the imaging support device. [Figure 4] FIG. 13 is a diagram showing an example of safety checks at the time of delivery. [Diagram 5] FIG. 4 is a flowchart for explaining the process of the imaging support device according to the first embodiment. [Figure 6] FIG. 11 is a flowchart for explaining the process of the imaging support device according to the second embodiment. [Figure 7] 13A and 13B are diagrams showing an example of arrangement in which the clearance is insufficient and an example of rearrangement after improvement. [Figure 8] FIG. 11 is a flowchart for explaining the process of the imaging support device according to the third embodiment. [Figure 9]FIG. 13 is a flowchart for explaining the process of the imaging support device according to the fourth embodiment. [Figure 10] FIG. 13 is a diagram showing an example of optimal channel presentation by the imaging support device of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the imaging support device of the present invention will be described. In the following description, the imaging device is an MRI device, and the device attached to the subject is mainly a receiving coil of the MRI device. However, the imaging device has an imaging space, and can be applied to a device that transports the subject into the imaging space to perform imaging, such as a CT device or a PET device, and the device can be a biological information measuring device such as an oxygen concentration measuring device or a heart rate monitor.

[0017] First, an imaging device that serves as a target of the imaging support device will be described.

[0018] 1A and 1B show an example of an imaging device 2 to which the present invention can be applied. This imaging device 2 includes a cylindrical gantry 21 having an imaging space (bore) therein, and a bed device for transporting a subject 6 into the bore. The bed device includes a table 22 on which the subject 6 is placed, and the subject 6 is carried into the bore by moving the table 22.

[0019] In the imaging device 2, one or more cameras 3 are installed at positions where the subject 6 before being carried into the imaging space can be imaged, and camera images of the subject 6 placed on the table 22 of the bed device are obtained. The type, number, and installation positions of the cameras are not particularly limited, and although FIG. 1A shows an example in which the cameras 3 are installed in two places, such as near the entrance of the gantry 21 and on the upper part or ceiling of the examination room, the number of cameras may be one or three or more, and the installation positions may be any position where the camera images required for the above-mentioned setting can be obtained. In addition, as shown in FIG. 1B, even if the camera 3 is installed inside the gantry, the image may be used as long as it allows the setting on the table to be confirmed.

[0020] Furthermore, the camera 3 may be a camera that captures two-dimensional images, or a stereo camera that can grasp a three-dimensional position. It may also be a camera with a video function or a tracking function. Regardless of the type of camera, an image captured by the camera is hereinafter referred to as a camera image. In other words, in this specification, the term "camera image" is used in a broad sense to include not only an image captured by a camera in the narrow sense, but also an image captured by an optical imaging device.

[0021] In the case of an MRI apparatus, a static magnetic field magnet, a gradient magnetic field generating magnet, and an RF transmitting coil are arranged in this order inside the gantry 21, and a uniform static magnetic field is generated in the imaging space by the static magnetic field magnet. In some cases, the RF transmitting coil also serves as an RF receiving coil for receiving nuclear magnetic resonance signals generated in the subject, but in order to receive the nuclear magnetic resonance signals with good sensitivity, an RF receiving coil 7 is attached to the subject.

[0022] 2, the gradient magnetic field generating magnet 202, the RF transmitting coil 203, and the RF receiving coil 204 (RF receiving coil 7) are connected to a gradient magnetic field power supply 212, an RF transmitting unit 213, and an RF receiving unit 214. The operations of the gradient magnetic field power supply 212, the RF transmitting unit 213, and the RF receiving unit 214 are controlled by a sequencer 215 in accordance with a predetermined pulse sequence.

[0023] The MRI apparatus 2A further includes a computer 20 that controls the entire apparatus and performs calculations such as image reconstruction using the nuclear magnetic resonance signal detected by the RF receiving unit 214. The computer 20 can be connected to a UI unit 5 that includes an external storage device 4 and a device 50 such as a display device that exchanges data necessary for control and image calculation, calculation results, and the like.

[0024] The imaging procedure by the MRI apparatus 2A is similar to that of a general MRI apparatus, and therefore a description thereof will be omitted in this specification.

[0025] The imaging support device 1 is a device that supports the preparation process from placing the subject 6 on the table 22, attaching the receiving coil 7 to the subject 6, and carrying it to a predetermined position in the imaging space when imaging is performed using such an MRI apparatus 2A. The imaging support device 1 can be constructed in a general-purpose computer or workstation, and may be incorporated in the computer 20 of the MRI apparatus 2A. Also, some of the functions of the imaging support device 1 can be realized by a programmable IC or the like.

[0026] 3 is a block diagram showing an outline of the functions of the imaging support device 1, which includes an optimal placement presentation unit 11 that presents an optimal placement of instruments such as the receiving coil 7 to be attached to the subject 6, a camera image acquisition unit 13 that acquires a camera image of the subject placed in the imaging device 2, a judgment unit 14 that judges the safety of the work using the camera image, and a UI unit 15 for communicating with imaging technicians, doctors, and the like (hereinafter referred to as operators).Furthermore, in some embodiments, the imaging support device 1 includes a body thickness estimation unit 16 that performs physical measurements or estimations such as the subject's body thickness, and a loop detection unit 17 that detects loops occurring in the instruments and the subject.

[0027] The imaging support device 1 is also connected to, as auxiliary devices, a camera 3 installed in a position in the imaging device 2 where the subject 6 can be imaged, an external storage device 40 that stores data and the like used for judgment by the judgment section 14, and devices 50 such as a display device, an input device, and a sound generating device connected to the UI section 15. When the imaging support device 1 in Fig. 2 is incorporated in a computer of an imaging device such as the MRI device 2A, the external storage device 4 and the UI section 5 connected to the computer 20 shown in Fig. 3 may also serve as the external storage device 40 and the UI section 15 (including the device 50) in Fig. 3.

[0028] 1 showing the imaging device 2, it is preferable to attach two or more cameras and use them as a stereo camera to support imaging. This makes it possible to measure the body thickness of the subject, and when a patient with a large build (large abdominal circumference) is placed in the bore, it is also possible to determine whether or not he or she can fit in the bore.

[0029] The camera image acquiring unit 13 acquires the camera image from the camera 3 at a predetermined timing, passes it to the determining unit 14, and displays it on the display device of the UI unit 15. The timing at which the camera image acquiring unit 13 acquires the camera image may be a timing instructed by the operator via the UI unit 15, or may be automatically acquired at a fixed interval or at a predetermined timing programmed in advance.

[0030] The determination unit 14 analyzes the camera image of the subject 6 with the receiving coil 7 attached, and determines whether safety is ensured when the subject 6 with the receiving coil 7 attached is transported into the bore. If necessary, a camera image of the subject before the receiving coil is attached is also acquired. The state where safety is an issue includes, for example, a state where a part of the subject 6's body, the receiving coil 7 attached to the subject 6, or a blanket covering the subject 6, etc., protrude from the table 22 on which the subject 6 is placed, as shown in FIG. 4, a state where the receiving coil 7 or the blanket may be entangled in the table when the subject 6 with the receiving coil 7 attached is transported into the gantry 21 of the imaging device 2, a state where a predetermined distance (clearance) is not maintained between the inner wall surface of the bore and the transported object, a state where a loop that provides a flow path for an induced current is formed or may be formed in the subject 6 or a cable (not shown) connected to the receiving coil 7, etc.

[0031] The optimal placement presentation unit 11 determines the optimal position for attaching the receiving coil from the viewpoint of image quality, for example, based on a camera image of the subject before the receiving coil is attached and examination information of the subject, and presents it on the camera image displayed on the display device of the UI unit 15. The method of determining the position by the optimal placement presentation unit 11 will be described in detail later.

[0032] Next, in consideration of the configuration of the imaging support device 1 described above, an embodiment of the processing of each unit will be described.

[0033] <Embodiment 1> In this embodiment, the basic processing of the imaging support device 1 will be described with reference to the flow shown in Fig. 5. Here, it is assumed that the camera 3 takes images continuously at a predetermined interval.

[0034] The camera image acquisition unit 13 acquires a camera image captured by the camera 3 when the subject 6 is placed on the table 22 of the bed device (S1). The camera image deviates from the actual distance and positional relationship of the subject depending on the position where the camera 3 is placed, but it is possible to calibrate it using information on the distance and angle between the camera and the subject, and the image after calibration may be used as the camera image.

[0035] The optimal placement presentation unit 11 determines the position at which the receiving coil 7 should be attached on the subject 6 based on the examination information input via the imaging device 2 or the UI unit 15, and displays the position on the camera image displayed on the display device of the UI unit 15 (S2).

[0036] The method of determining and presenting the optimum placement of the receiving coil from the viewpoint of image quality is not limited, but for example, when a user specifies the position of an examination site, for example, the position of the heart, on a camera image displayed on a display device, the position where the center of the receiving coil coincides with that position is determined as the optimum placement, and this optimum placement is presented on the camera image. Alternatively, projection light from a projector provided in the imaging device is irradiated on the examination site of the subject, and the receiving coil position is presented on the camera image so that the center of the receiving coil coincides with that position. At this time, receiving coil information including the type, size, and shape of the receiving coil may be stored in the external storage device 4 in advance, and the stored information may be read out for the receiving coil actually used for imaging, and a figure of the outline of the receiving coil, which has been appropriately scaled, may be placed on the camera image to display the position on the camera image. Alternatively, for simplicity, a template image showing the optimum attachment site in consideration of image quality may be prepared in advance for each examination site, imaging information including the examination site may be obtained from the imaging device 2, and the template image may be presented.

[0037] The camera image acquisition unit 13 acquires the camera image captured by the camera after the receiving coil is attached from the camera images captured by the camera 3 continuously or at predetermined intervals, and passes it to the determination unit 14 (S3). The timing of acquiring the camera image after the receiving coil is attached or passing it to the determination unit 14 may be determined by the user via an input device or the like of the UI unit 15, or the timing at which the receiving coil 7 is connected to the imaging device 2 (receiver) may be received from the imaging device 2 and used as the timing for acquiring the camera image.

[0038] The determination unit 14 analyzes the camera image of the subject with the receiving coil attached to check the safety. For example, as shown in Fig. 4, it checks whether a part of the subject 6's body or the receiving coil 7 and accessories attached to the subject 6 protrudes from the table 22 (case 1), whether a loop 71a is formed or may be formed between the cable 71 of the receiving coil 7 itself or the cable 71 and the subject 6 (case 2), whether a sufficient gap (clearance) is secured between the subject 6 covered with the receiving coil 7 or a blanket or the like and the imaging space (the inner wall surface of the bore) (case 3), and so on (S4).

[0039] The protrusion from the table 22 can be determined, for example, from a difference between a previously acquired image of only the table and the reference image. By determining the excess of the receiving coil 7 and its accessories in this manner, when the receiving coil is wrapped around the limbs, etc., it is possible to prevent the excess coil portion from becoming entangled in the structure of the imaging device, such as a bed device, due to the subject's movement.

[0040] Regarding the formation of a loop, if a loop has occurred at the time of placing the receiving coil, the loop detection unit 17 can determine the presence or absence of a loop-shaped figure by image processing of the camera image. Regarding a loop that may occur during transportation, the determination unit 14 predicts the occurrence of a loop accompanying the movement of the table 22 based on the running state of the cable 71 between the receiving coil 7 and the receiving coil connection unit 72. For example, if the cable 71 coming out of the receiving coil 7 is placed along the body axis direction of the subject 6 and is gently bent near the connection unit 72 and connected to the connection unit 72, there is little possibility that a loop will occur between the subject 6 and the cable 71 even if the table 22 moves, but if the cable 71 is placed so as to deviate from the subject 6, a loop is likely to be formed as the table 22 moves, and in some cases, it may even protrude from the table 22. In other words, the likelihood of a loop occurring can be predicted by detecting the length and the angle with respect to the table movement direction for a predetermined length of cable from the cable connection unit of the receiving coil 7. The judgment unit 14 detects the distance between the cable connection part and the end of the table, the length of the cable, the angle of the cable run, etc. from the camera image, and based on the results, predicts the occurrence of a loop and confirms safety.

[0041] In this way, by detecting the geometric information of the cable when the receiving coil is placed and predicting subsequent changes, it is possible to detect and warn in advance of the occurrence of loops or even the risk of the cable wrapping around a part of the subject, such as the arm.

[0042] Whether or not sufficient clearance is maintained will be described in detail in embodiment 2, but this is determined by comparing the actual or estimated size of the subject (body thickness or abdominal circumference) after the subject or instrument, etc. is attached with the size of the bore.

[0043] In addition to the safety checks (cases 1 to 3) regarding the patient position, coil position, and cable, it is preferable that the judgment unit 14 checks the safety by detecting the cable of the SPO2 sensor attached to the patient's finger and the blanket placed over the patient. In particular, there is a risk that a thin blanket may be entangled in the table and its support when the table is moved. The judgment unit 14 detects the blanket and judges the blanket installation status, for example, whether the blanket position is within a predetermined range, thereby predicting the occurrence of entanglement and preventing entanglement.

[0044] In addition, the above prediction is a rule-based judgment of the conditions that impair safety, but predictions using machine learning models or AI that have learned various types of image data that impair safety are also possible. That is, the judgment unit 14 can be constructed in part or in whole using machine learning models or AI.

[0045] If the judgment unit 14 judges that there is a safety problem as a result of the judgment (in the case of NG judgment in S4), it issues an alert via the UI unit 15 (S5). The alert may be, for example, displayed on a gantry monitor installed at the bore entrance as OK or NG from the viewpoint of safety, or may be notified by an alert sound. Furthermore, as an alert display, for example, the problematic area may be indicated by an arrow or a square on the camera image displayed on the display device. Alternatively, an icon or template image may be displayed. This allows the user to immediately recognize the problematic area and deal with it.

[0046] After the user deals with the safety problem in response to the alert, the camera image acquisition unit 13 acquires the camera image again (S6). For example, if there is a problem with the position of the receiving coil, the user takes measures such as repositioning the receiving coil while maintaining the initially presented optimal position as much as possible.

[0047] The camera image acquisition unit 13 passes the camera image after the problematic area has been addressed (for example, after the receiving coils have been rearranged) to the determination unit 14, and repeats the processes S4 to S6 until it is confirmed that there is no problem with safety.

[0048] Thereafter, the table 22 is moved to transport the subject 6 into the imaging space so that the center of the receiving coil 7 is located at the center of the bore, i.e., the center of the static magnetic field space. Although not shown in Fig. 5, camera images are acquired during this transport as well, and it is monitored whether any problems arise due to movements that occur during transport.

[0049] Thus, according to this embodiment, the subject 6 is brought into the imaging space with the receiving coil 7 attached in an optimal position taking image quality into consideration, while ensuring safety. This ensures safety during the setup work while ensuring image quality, eliminates the need for repeated table movements, and prevents improper positioning due to reattaching the receiving coil and the resulting degradation of image quality.

[0050] <Embodiment 2> In this embodiment, we will explain an imaging support device that has a function to determine whether sufficient clearance is secured between the receiving coil 7, the subject 6 covered with a blanket, etc., and the imaging space (the inner wall surface of the bore), particularly as a safety confirmation item.

[0051] In order to perform this determination, the imaging support device 1 of this embodiment includes a body thickness estimation unit 16, which estimates the body thickness (thickness in a direction perpendicular to the table surface) of the subject 6 from the camera image. The functional block diagram of the device of this embodiment is similar to that of FIG.

[0052] The flow of processing in this embodiment is shown in Fig. 6. In Fig. 6, the same processes as in Fig. 5 are denoted by the same reference numerals, and overlapping explanations will be omitted, with differences being mainly explained.

[0053] First, the optimal placement presenter 11 presents an optimal placement of the receiving coils using a camera image (S1, S2), and the camera image acquirer 13 acquires a camera image after the receiving coils are attached (S3). The body thickness estimator 16 estimates the body thickness using the camera image (S31).

[0054] If the camera 3 is installed next to the bed, the side of the subject is captured in the camera image, and the subject's vertical height, i.e., the subject's body thickness, can be estimated from the image. Alternatively, if the camera 3 is a stereo camera, the subject's body thickness can be estimated from two camera images taken from different angles.

[0055] The determination unit 14 determines the thickness of the test object to be the sum of the body thickness estimated by the body thickness estimation unit 16 and the thickness of the receiving coil 7 previously acquired, calculates the difference between the geometric values ​​(elliptical shape, height, width) of the imaging space and the thickness, and judges whether the difference is within an allowable clearance (S4). An appropriate range of clearance is determined in advance for each device, taking into account the strength of the magnetic field generated by the RF transmitting coil housed in the gantry. For example, the determination unit 14 acquires it from the external storage device 4 or the imaging device 2.

[0056] When the determination unit 14 determines that the distance between the inspection object and the bore inner wall surface does not satisfy a predetermined clearance based on the result estimated by the body thickness estimation unit 16, an alert is issued (S5) in the same manner as in the flow of Fig. 5, but it is preferable that the alert display not only indicates safety NG or OK, but also informs the user that the clearance is not satisfied. For example, a template image 801 or text information as shown in Fig. 7 may be displayed. This allows the user to narrow down the problematic area and deal with it.

[0057] If the user repositions the receiving coil after the alert is issued, a camera image is acquired (S6), and steps S4 to S6 are repeated.

[0058] At this time, as shown by the dotted line in the flow of Fig. 6, the optimum arrangement presenting unit 11 may present the optimum arrangement of the receiving coils (S52) according to the determination result of the determining unit 14 (S51). For example, as shown in Fig. 7, when the mounting of the receiving coil 7 extremely reduces the clearance with the upper surface of the inner wall of the gantry (801), the arrangement and type of the receiving coil 7 that can avoid contact between the upper surface and the receiving coil and maintain good reception sensitivity for the examination region 800 is presented (802). The presentation method may be a presentation using an image (template image or displayed camera image), or may also be combined with text information indicating the type of receiving coil.

[0059] This enables the user to wear a receiving coil that ensures safety while ensuring image quality.

[0060] In addition, in Fig. 6, a case where the body thickness of the subject 6 is an issue has been described, but in addition to body thickness, the clearance with the inner surface of the bore may also be an issue depending on the body build and posture of the subject. In this case, too, the maximum height and width of the volume occupied by the subject are estimated from an image captured by a camera installed near the ceiling of the examination room, or the maximum height and width are obtained from the results of measurements taken in advance, and then judgment is made. In this case, the same processing is performed, except that the "body thickness estimation unit" in Fig. 3 is replaced with the "volume estimation unit."

[0061] According to this embodiment, when a patient with a large build (large waist circumference) is placed in the bore, it is possible to determine whether or not the patient can fit into the bore. Furthermore, it is possible to determine in advance the safety inhibition conditions after the placement of the instruments, which are difficult to determine at a glance, and then find the optimal placement of the receiving coils. This makes it possible to prevent discomfort of the subject due to insufficient clearance, and in extreme cases, effects on the subject due to being too close to the RF transmitting coil.

[0062] <Embodiment 3> In the first and second embodiments, it has been explained that the steps from the judgment step S4 to the camera image acquisition step S6 after rearrangement of the receiving coil are repeated until the judgment unit 14 judges that there is no problem with safety. However, the present embodiment provides a method for making the setting more efficient by keeping the number of repetitions within an appropriate range.

[0063] Therefore, in the imaging support device 1 of this embodiment, the determination unit 14 counts the number of repetitions, and the optimal layout presentation unit 11 presents alternative receiver coil layouts different from the initially presented receiver coil layout. Since the configuration of the device is similar to that of the other embodiments, the processing of the imaging support device 1 of this embodiment will be described below with reference to the flow of Fig. 8. In Fig. 8, steps having the same content as those shown in Figs. 5 and 6 are indicated by the same reference numerals, and duplicated descriptions will be omitted.

[0064] After acquiring a camera image (S1), the optimal placement presenting unit 11 presents an optimal receiving coil placement using the camera image (S21). This step S21 is basically the same as step S2 in the first and second embodiments, but here, the mounting position is presented after excluding setting positions that are problematic from the viewpoint of safety. For example, when the examination site is the heart, one arm or leg, and the like, which is shifted in the left-right direction from the center of the subject, or when the examination site has a large area, if the receiving coil is set so that the center of the receiving coil is located at the center of the examination site, in the case of a multi-channel coil having a relatively large area, the receiving coil may extend beyond the edge of the table. For example, the optimal placement presenting unit 11 compares the position and range of the examination site specified by the camera image with the size of the receiving coil, and presents the optimal receiving coil position by excluding setting positions where the receiving coil extends beyond the table.

[0065] The elimination of safety NGs in this step may be simpler than the safety judgment by the judgment unit 14, but by eliminating configurations that have easily predictable safety problems in advance, the number of repetitions of the safety judgment loop thereafter can be reduced.

[0066] After the user wears the receiving coil according to the presented receiving coil position, the judgment unit 14 acquires a camera image after wearing (S3) and judges whether safety is maintained (S4). If the safety is NG, an alert is displayed (S5), a camera image after the receiving coil is rearranged is acquired (S6), and safety is judged again (S4). The judgment unit 14 monitors the number of times the safety judgment, i.e., the rearrangement, has been repeated (S7), and when the number of times exceeds a predetermined number (N), the judgment loop is stopped and the optimal arrangement presentation unit 11 presents a second option (S71). The second option is an arrangement that is equivalent to the initially presented optimal receiving coil arrangement in terms of image quality or can maintain a relatively good image quality, and includes the use of a different type of receiving coil and its arrangement.

[0067] For example, for a large patient, if the initially proposed arrangement is optimal from the standpoint of image quality, but the arrangement is too close due to the distance between the patient and the bore and the alert does not disappear even after repeated rearrangements, the coil position is changed or a different receiving coil is selected, as shown in Figure 7, and this is presented as the second optimal arrangement.

[0068] When the receiving coils are arranged in the presented second optimum arrangement, the camera image acquisition unit 13 acquires a camera image (S72), and the above-mentioned steps S4 to S7 are repeated again.

[0069] According to this embodiment, since it is not necessary to repeatedly perform the work of one optimal arrangement proposed in terms of image quality, it is possible to improve the efficiency of the work. Although not shown in Fig. 8, after step S7 of determining the number of rearrangements, it is also possible to accept a user instruction as to whether or not to stop imaging, and thus, when safety cannot be ensured simply by the arrangement of the instruments and the subject, the user may be prompted to reconsider the imaging method.

[0070] <Embodiment 4> In this embodiment, the optimum placement presenting unit 11 has an additional function of presenting not only the mounting position of the receiving coil but also the optimum coil position for improving image quality when the receiving coil is a multi-channel coil.

[0071] The receiver coils currently widely used in MRI devices are multi-channel coils that have many surface coils arranged to increase sensitivity and enable wide-area imaging. Multi-channel coils have the advantage of being able to image a relatively wide area at once with high sensitivity, but when imaging a limited examination area, there is a possibility that noise will increase because signals from coils of channels located relatively far from the area are also included in the image reconstruction. In addition, some multi-channel coils have more channels than the receiver channels of the receiver coil of the imaging device 2, and in such cases it is necessary to select which channels to use and which not to use.

[0072] In the imaging support device 1 of this embodiment, when a multi-channel coil is used, a function is added to present one or more channels that are optimal in terms of image quality from among the many channels that constitute the multi-channel coil. This channel presentation function may be a function of the optimal layout presentation unit 11 shown in FIG. 3, or a channel presentation unit (not shown) may be provided separately. Here, the optimal layout presentation unit 11 in FIG. 3 will be replaced with the channel presentation unit for explanation. The other configurations and the function of the determination unit 14 are the same as those of the above-mentioned embodiment. Below, this embodiment will be explained, focusing on the differences.

[0073] FIG. 9 is a flow chart showing the process of the imaging support device of this embodiment, and this flow is the same as that of the first embodiment except that step S20 is substituted for step S2 of the flow of the first embodiment shown in FIG.

[0074] In step S20, first, the optimum placement presentation unit 11 presents the optimum receiving coil position from the viewpoint of image quality. At that time, the optimum placement is presented after excluding setting positions that are problematic from the viewpoint of safety. This process is the same as step S21 in FIG. 8, and the optimum placement is determined and presented using the camera image in a simple manner, for example, excluding placements that extend beyond the table. In the optimum position presented in this way, the center of the receiving coil does not necessarily coincide with the center of the examination region. In order to obtain good image quality, it is important to reconstruct using signals received at channels in a predetermined range centered on the examination region.

[0075] Therefore, the channel presenting unit selects, as active channels, channels within a predetermined region including the examination region from among the multiple channels of the receiving coil. FIG. 10 shows, as an example, an examination region 61 on the left side of the chest of the subject 6, and presents optimal receiving coil positions and optimal channel positions excluding left safety NG. In this example, a multi-channel coil capable of imaging the trunk of the subject 6 is used, and the examination region 61 of the subject 6 is biased to the left side, so a position where the center of the receiving coil is shifted from the center of the examination region and does not go beyond the table is presented as the optimal position, and a certain region including the examination region 61 and centered on the examination region 61 is presented. The channel included in this certain region is the optimal channel. Note that the range of the optimal channel is presented here, but conversely, unused channels may be presented.

[0076] The information indicating the optimal channel is reflected in the imaging device 2. For example, the method of reflection may involve a user manually setting the channel to be active using the presented information on the optimal channel, or the information may be sent to the imaging device 2 together with geometry information of the multi-channel coil, and the imaging device 2 may automatically turn on the selected optimal channel.

[0077] In this way, in step S20, after presenting the optimum position and optimum channel of the receiving coil, the camera image after mounting is acquired, safety is predicted, and an alert is issued as necessary (S4 to S6) as in other embodiments, and therefore a description thereof will be omitted. In this embodiment, too, a step of reducing the safety judgment cycle may be added as in the flow of Fig. 8, and a second option for the optimum arrangement may be presented as necessary. If the optimum arrangement is changed, the presentation of the optimum channel is also changed as necessary.

[0078] According to this embodiment, by presenting the optimal channel in addition to the optimal mounting position, it is possible to ensure good image quality and assist in safe setting.

[0079] Although the imaging support device and imaging support method of the present invention have been described above as being mainly applied to MRI, the present invention can be applied not only to MRI devices, but also to devices that transport a subject into a bore and perform imaging. In addition, the individual embodiments or the individual processes included therein can be appropriately combined as long as there is no technical contradiction, and such combinations are also included in the present invention. [Explanation of symbols]

[0080] 1: imaging support device, 2: imaging device, 2A: MRI device, 3: camera, 4, 40: external storage device, 50: device (display device and input device), 6: subject, 7: instrument (receiving coil), 11: optimal placement presentation unit, 13: camera image acquisition unit, 14: judgment unit, 5, 15: UI unit, 16: body thickness estimation unit, 17: loop detection unit, 21: gantry, 22: table, 71: cable

Claims

1. An imaging support device that supports a task of setting a subject in an imaging device having an imaging space and a table on which the subject is placed and which transports the subject to the imaging space, a camera image acquisition unit that acquires a camera image of the subject placed on the table; an optimal placement presenting unit that presents an optimal placement of an instrument to be attached to the subject using the camera image; and a judgment unit that judges safety during setting work using a camera image of a subject wearing the instrument.

2. The imaging support device according to claim 1 , The imaging support device, wherein the determination unit determines whether or not a gap between a subject wearing the instrument and an inner wall surface of the imaging space satisfies a predetermined value.

3. The imaging support device according to claim 2, a body thickness estimation unit that estimates a body thickness of the subject, The imaging support device, wherein the determination unit performs the determination using the body thickness estimated by the body thickness estimation unit.

4. The imaging support device according to claim 1 , The imaging support device, wherein the determination unit predicts entrapment of an accessory associated with the subject or the instrument when the subject is carried into the imaging space.

5. The imaging support device according to claim 1 , The imaging support device, wherein the determination unit predicts whether or not a loop will occur between the instrument and a cable connected thereto, or between the cable and the subject.

6. The imaging support device according to claim 5, An imaging support device characterized in that the judgment unit predicts the occurrence of the loop using geometric information of the cable, including the length of the cable and the connection angle relative to the instrument, obtained from the camera image.

7. The imaging support device according to claim 1 , An imaging support device characterized in that the determination unit makes the determination using a learning model that has learned the arrangement of the instruments and accessories on the subject and the change in the arrangement after the subject moves.

8. The imaging support device according to claim 1 , the device being a receive coil for use in a magnetic resonance imaging device; The imaging support device, wherein the optimum arrangement presenting unit presents, as an optimum arrangement, an arrangement position of the receiving coils that can obtain high image quality for the examination region of the subject.

9. The imaging support device according to claim 8, The imaging support device is characterized in that the optimal layout presenting unit presents, as the optimal layout, a layout that excludes layouts in which safety of settings cannot be ensured.

10. The imaging support device according to claim 8, An imaging support device, characterized in that the optimal layout presented by the optimal layout presentation unit includes any one of the position, type, and number of the receiving coils.

11. The imaging support device according to claim 8, The receiving coil is a multi-channel coil having a plurality of channels, The imaging support device, wherein the optimal layout presentation unit includes a channel presentation unit that presents some of the multiple channels as optimal channels that can provide high image quality.

12. The imaging support device according to claim 1 , The imaging support device further comprises a user interface unit that issues an alert depending on a determination result of the determination unit.

13. The imaging support device according to claim 1 , The imaging support device, wherein the optimal layout presentation unit presents a second optimal layout different from the optimal layout in accordance with a determination result of the determination unit.

14. an imaging unit including an imaging space in which a static magnetic field is generated, a table for transporting a subject to the imaging space, an RF transmitting unit for generating an RF magnetic field in the imaging space, and an RF receiving unit for receiving a nuclear magnetic resonance signal generated from the subject; and a calculation unit for controlling the imaging unit and performing image reconstruction using the nuclear magnetic resonance signal, The calculation unit is a camera image acquisition unit that acquires a camera image of the subject placed on the table before the subject is transported to the imaging space; an optimal placement presenting unit that presents an optimal placement of an instrument to be attached to the subject using the camera image; a determination unit that determines the safety of an operation of setting the subject in the imaging space by using a camera image of the subject wearing the tool.

15. A method for assisting an operation of setting a subject in an imaging apparatus having an imaging space and a table for placing the subject on the table and transporting the subject to the imaging space, comprising: a camera image acquiring step of acquiring a camera image of the subject placed on the table; an optimal arrangement presenting step of presenting an optimal arrangement of an instrument to be attached to the subject using the camera image; A determination step of determining the safety of the setting work using a camera image of the subject wearing the tool; and a result presenting step of presenting a determination result of the determining step.

16. The imaging support method according to claim 15, After the result presentation step, when the tool is repositioned, An imaging support method, comprising repeating the determining step and the result presenting step.

17. The imaging support method according to claim 16, An imaging support method, further comprising a second optimal layout presentation step of presenting a second optimal layout different from the optimal layout when the repetition of the determination step and the result presentation step exceeds a predetermined number of times.

Images