Motion artifact correction system for magnetic resonance image

Abstract

The present invention relates to a motion artifact correction system for a magnetic resonance image, comprising: a magnetic compatible optical imaging subsystem and a correction subsystem. The magnetic compatible optical imaging subsystem and a target object are located in a same magnetic resonance environment; the magnetic compatible optical imaging subsystem is used for determining, during magnetic resonance imaging of the target object, a multi-view real-time optical image corresponding to the target object; and the correction subsystem is used for performing, on the basis of the multi-view real-time optical image, motion artifact correction on an initial magnetic resonance image corresponding to the target object having undergone magnetic resonance imaging, and determining an artifact-free magnetic resonance image corresponding to the target object. The motion artifact correction system in embodiments of the present invention has a high anti-electromagnetic interference capability, can be arranged in a magnetic resonance environment, performs real-time motion tracking on a target object under a relatively good observation view field, and implements collection of a multi-view real-time optical image, so as to perform motion artifact correction on an initial magnetic resonance image, thereby obtaining a high-quality artifact-free magnetic resonance image.

Description

A motion artifact correction system for magnetic resonance imaging

[0001] This application claims priority to Chinese Patent Application No. 202410917039.3, filed on July 9, 2024, entitled "A Motion Artifact Correction System for Magnetic Resonance Images", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of magnetic resonance medical technology, and in particular to a motion artifact correction system for magnetic resonance images. Background Technology

[0003] Magnetic resonance imaging (MRI) is a crucial basis for medical diagnosis, and its clarity significantly impacts the accuracy of these diagnoses. Current MRI sequences typically require lengthy acquisition times to gather sufficient data for image formation. During acquisition, patients inevitably engage in various physiological activities, such as head rotation and chest and abdominal movements during respiration, which can cause motion interference in the MRI images, resulting in motion artifacts and reducing image quality.

[0004] Summary of the Invention

[0005] In view of this, this disclosure proposes a technical solution for a motion artifact correction system for magnetic resonance images.

[0006] According to one aspect of this disclosure, a motion artifact correction system for magnetic resonance imaging is provided, comprising: a magnetically compatible optical imaging subsystem and a correction subsystem, wherein the magnetically compatible optical imaging subsystem and the target object are located in the same magnetic resonance environment; the magnetically compatible optical imaging subsystem is used to determine a multi-view real-time optical image corresponding to the target object during magnetic resonance imaging of the target object; the correction subsystem is used to perform motion artifact correction on an initial magnetic resonance image corresponding to the target object obtained by magnetic resonance imaging based on the multi-view real-time optical image, thereby determining an artifact-free magnetic resonance image corresponding to the target object.

[0007] In one possible implementation, the magnetically compatible optical imaging subsystem includes: multiple magnetic resonance-compatible cameras and a data transmission module, wherein different magnetic resonance-compatible cameras are positioned at different locations in the magnetic resonance environment; any one magnetic resonance-compatible camera is used to determine a real-time optical image of the target object from the viewpoint corresponding to that magnetic resonance-compatible camera; the data transmission module is used to transmit the multi-view real-time optical image to the correction subsystem.

[0008] In one possible implementation, any magnetic resonance compatible camera includes a monocular camera and a magnetically shielded housing.

[0009] In one possible implementation, the data transmission module includes an optical fiber, a gigabit Ethernet communication interface converter, and an Ethernet cable; the optical fiber is connected to the gigabit Ethernet communication interface converter and the magnetic resonance compatible camera signal, respectively, and the Ethernet cable is connected to the gigabit Ethernet communication interface converter and the correction subsystem signal, respectively.

[0010] In one possible implementation, the magnetically compatible optical imaging subsystem further includes a power module, which includes a power supply, a power filter, a waveguide, and a power supply cable disposed within the waveguide.

[0011] In one possible implementation, the correction subsystem is used to: determine motion detection data corresponding to the target object based on the multi-view real-time optical image; and perform motion artifact correction on the initial magnetic resonance image based on the motion detection data to determine the artifact-free magnetic resonance image.

[0012] In one possible implementation, the target object corresponds to multiple reference marker points; the correction subsystem is used to: determine the real-time position information corresponding to each reference marker point based on the multi-view real-time optical image; and determine the motion detection data based on the real-time position information corresponding to each reference marker point.

[0013] In one possible implementation, the correction subsystem is used to: for any given reference marker, determine the motion information corresponding to the reference marker based on the real-time position information corresponding to the reference marker; and determine the motion detection data based on the motion information corresponding to each reference marker.

[0014] In one possible implementation, the correction subsystem is used to: perform dimensional transformation on the motion detection data to determine k-space motion data; correct the k-space motion data to determine corrected k-space motion data; and correct the initial magnetic resonance image based on the corrected k-space motion data to determine the artifact-free magnetic resonance image.

[0015] In one possible implementation, the k-space motion data includes: rotation trajectory data and translational motion data; the correction subsystem is used to: perform angle correction on the rotation trajectory data to determine the corrected rotation trajectory data; and perform phase correction on the translational motion data to determine the corrected translational motion data.

[0016] The motion artifact correction system for magnetic resonance imaging (MRI) according to this disclosure includes a magnetically compatible optical imaging subsystem and a correction subsystem. The magnetically compatible optical imaging subsystem can be placed in the same MRI environment as the target object, thereby providing it with a better field of view. During MRI of the target object, it can accurately track the target object's motion in real time, determine the corresponding multi-view real-time optical image, ensure the effectiveness and reliability of the multi-view real-time optical image, and reduce the impact on the MRI process, exhibiting high versatility and accuracy. The correction subsystem can correct motion artifacts in the initial MRI image corresponding to the target object obtained from the multi-view real-time optical image, determining the artifact-free MRI image of the target object, thus improving the quality and reliability of the artifact-free MRI image.

[0017] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0019] Figure 1 shows a block diagram of a motion artifact correction system for magnetic resonance images according to an embodiment of the present disclosure;

[0020] Figure 2 shows a schematic diagram of a motion artifact correction system for magnetic resonance images according to an embodiment of the present disclosure;

[0021] Figure 3 shows a schematic diagram of a location reconstruction according to an embodiment of the present disclosure. Detailed Implementation

[0022] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0023] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0024] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0025] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0026] Magnetic resonance imaging (MRI) is a crucial basis for medical diagnosis, and its clarity significantly impacts the accuracy of these diagnoses. Current MRI sequences typically require lengthy acquisition times to gather sufficient data for image formation. During acquisition, patients inevitably engage in various physiological activities, such as head rotation and chest and abdominal movements during respiration, which can cause motion interference in the MRI images, resulting in motion artifacts and reducing image quality.

[0027] In existing technologies, one method for detecting patient motion during magnetic resonance imaging (MRI) involves adding a separate navigation echo signal before or after each MRI image acquisition to obtain patient motion information, which is then used to correct motion artifacts in the MRI images. However, this method typically increases the MRI image acquisition time and may affect the acquisition of the original MRI signal.

[0028] Another commonly used method in the prior art is the magnetic field probe method. This method uses at least one signal coupling coil to capture gradient-coded field signals in the magnetic resonance environment. The position of the signal coupling coil is determined based on its spatial location and the correspondence with the gradient-coded field signals, thereby calculating the patient's motion information. This motion information is then used to correct motion artifacts in the patient's magnetic resonance images. However, the detection sensitivity of this method is limited by the orientation of the magnetic resonance imaging device and requires adjustment based on the radiofrequency pulse scheme corresponding to the device. This results in poor adaptability and prevents its widespread application to magnetic resonance imaging devices with different radiofrequency pulses.

[0029] Another existing method is motion tracking based on optical equipment. This method uses optical equipment independent of the magnetic resonance imaging (MRI) unit to acquire real-time images of markers placed on the patient. The real-time spatial position of the markers is then determined through spatial geometry to ascertain the patient's motion information. Motion artifact correction is then applied to the patient's MRI images based on this motion information. However, the optical equipment in this method is typically located outside the MRI environment, resulting in a limited field of view, susceptibility to obstruction by the MRI unit, and the accuracy of marker tracking is affected by the coupling effect between the markers and the patient's body.

[0030] In view of this, embodiments of the present disclosure provide a motion artifact correction system for magnetic resonance imaging (MRI). This system can be placed within the same MRI environment as the target object, acquiring multi-view real-time optical images of the target object during MRI. Motion artifact correction is then performed using the initial MRI image corresponding to the target object, reducing the impact on the MRI process and exhibiting high versatility and accuracy. The motion artifact correction system for MRI images of the present disclosure will be described in detail below.

[0031] Figure 1 shows a block diagram of a motion artifact correction system for magnetic resonance imaging according to an embodiment of the present disclosure. As shown in Figure 1, the system 100 includes a magnetically compatible optical imaging subsystem 101 and a correction subsystem 102, wherein the magnetically compatible optical imaging subsystem 101 is located in the same magnetic resonance environment as the target object. The magnetically compatible optical imaging subsystem 101 is used to determine a multi-view real-time optical image corresponding to the target object during magnetic resonance imaging of the target object. The correction subsystem 102 is used to perform motion artifact correction on the initial magnetic resonance image corresponding to the target object obtained by magnetic resonance imaging based on the multi-view real-time optical image, thereby determining an artifact-free magnetic resonance image corresponding to the target object.

[0032] The target object here can refer to the object that needs to be subjected to magnetic resonance imaging, such as a patient, or it can only include the patient's examination site (head, chest cavity, etc.). It can be flexibly set according to actual usage needs, and this disclosure does not make specific limitations in this regard.

[0033] The magnetic resonance environment here can refer to the magnetic field generated in space by the magnetic resonance imaging device used to perform magnetic resonance imaging (MRI) on a target object.

[0034] The magnetically compatible imaging subsystem 101 can determine the multi-view real-time optical image of the target object during magnetic resonance imaging (MRI). Since the magnetically compatible imaging subsystem 101 and the target object are within the same magnetic resonance environment, the magnetically compatible imaging subsystem 101 has a better field of view and can accurately focus on the target object, reducing the possibility of obstruction by the MRI device or other medical equipment. This ensures the target object is complete and clear in the multi-view real-time optical image, thereby improving the reliability of subsequent motion artifact correction based on the multi-view real-time optical image. Simultaneously, real-time motion tracking of the target object based on the independent magnetically compatible imaging subsystem 101 causes less interference to the MRI process, thus reducing the impact on the quality of the initial MRI image.

[0035] Among them, the multi-view real-time optical image may include optical images of the target object from at least two different observation views. Its specific form and content can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0036] The magnetically compatible optical imaging subsystem 101 will be described in detail later in conjunction with the possible implementations of this disclosure, and will not be repeated here.

[0037] The magnetic compatibility imaging subsystem 101 can be signal-connected to the correction subsystem 102 to transmit multi-view real-time optical images to the correction subsystem 102. This signal connection indicates that the magnetic compatibility imaging subsystem 101 and the correction subsystem 102 are electrically connected and capable of data transmission; the specific method of data transmission can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0038] The correction subsystem 102 can perform motion artifact correction on the initial magnetic resonance image corresponding to the target object obtained by magnetic resonance imaging based on multi-view real-time optical images, thereby determining an artifact-free magnetic resonance image corresponding to the target object. The specific form of the correction subsystem 102 can refer to implementation methods in related technologies. For example, it can be executed by electronic devices such as terminal devices or servers. The terminal device can be a user equipment (UE), mobile device, user terminal, terminal, cellular phone, cordless phone, personal digital assistant (PDA), handheld device, computing device, in-vehicle device, wearable device, etc., and this disclosure does not specifically limit its implementation. Optionally, the correction subsystem 102 can be located outside the magnetic resonance environment to ensure the stability and safety of its operation. The specific method by which the correction subsystem 102 performs motion artifact correction on the initial magnetic resonance image can refer to implementation methods in related technologies, and this disclosure does not specifically limit its implementation.

[0039] The correction subsystem 102 will be described in detail later in conjunction with the possible implementation methods of this disclosure, and will not be repeated here.

[0040] The motion artifact correction system for magnetic resonance imaging (MRI) according to this disclosure includes a magnetically compatible optical imaging subsystem and a correction subsystem. The magnetically compatible optical imaging subsystem can be placed in the same MRI environment as the target object, thereby providing it with a better field of view. During MRI of the target object, it can accurately track the target object's motion in real time, determine the corresponding multi-view real-time optical image, ensure the effectiveness and reliability of the multi-view real-time optical image, and reduce the impact on the MRI process, exhibiting high versatility and accuracy. The correction subsystem can correct motion artifacts in the initial MRI image corresponding to the target object obtained from the multi-view real-time optical image, determining the artifact-free MRI image of the target object, thus improving the quality and reliability of the artifact-free MRI image.

[0041] In one possible implementation, the magnetically compatible optical imaging subsystem 101 includes: multiple magnetic resonance compatible cameras and a data transmission module, wherein different magnetic resonance compatible cameras are set at different locations in the magnetic resonance environment; any one magnetic resonance compatible camera is used to determine the real-time optical image corresponding to the target object from the viewpoint corresponding to the magnetic resonance compatible camera; the data transmission module is used to transmit the multi-view real-time optical images to the correction subsystem 102.

[0042] Figure 2 shows a schematic diagram of a motion artifact correction system for magnetic resonance imaging according to an embodiment of the present disclosure. As shown in Figure 2, the magnetically compatible optical imaging subsystem 101 includes: a plurality of magnetic resonance compatible cameras 201 and a data transmission module 202. The different magnetic resonance compatible cameras are positioned at different locations within the magnetic resonance environment.

[0043] Any magnetic resonance compatible camera 201 can be placed within the same magnetic resonance environment as the target object, and different magnetic resonance compatible cameras 201 can be placed at different positions within this magnetic resonance environment to facilitate the acquisition of real-time optical images from different perspectives. The specific structure of the magnetic resonance compatible camera 201 can be flexibly configured according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0044] In one possible implementation, any magnetic resonance compatible camera 201 includes a monocular camera and a magnetically shielded housing.

[0045] The specific form of the monocular camera can be referred to in the implementation methods in related technologies, and this disclosure does not make specific limitations on it.

[0046] The magnetic shielding shell can be used to reduce the probability of the magnetic resonance environment affecting the internal circuitry of a monocular camera, ensuring the safety and reliability of the magnetic resonance compatible camera 201. The specific form of the magnetic shielding shell can be found in related technical embodiments, and it can be made of magnetic shielding material; this disclosure does not impose any specific limitations on it.

[0047] The setup of the magnetic resonance compatible camera 201 in a magnetic resonance environment can be flexibly configured according to actual usage requirements. For example, the magnetic resonance compatible camera 201 can be set up in a magnetic resonance environment using an optical bracket, and the observation angle of the magnetic resonance compatible camera 201 can be flexibly adjusted by locking the set screw of the bracket, so that the magnetic resonance compatible camera 201 can focus on the target object, etc. This disclosure does not make specific limitations in this regard.

[0048] The specific location of each MRI-compatible camera 201 can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0049] The specific number of magnetic resonance compatible cameras 201 can be flexibly set according to actual usage requirements, and this disclosure does not impose a specific limitation on it. Optional magnetically compatible optical imaging subsystem 101 includes at least two magnetic resonance compatible cameras 201.

[0050] The data transmission module 202 is connected to each MRI-compatible camera 201 and the correction subsystem 102, respectively, and can transmit the real-time optical image of the target object determined from the viewpoint of each MRI-compatible camera to the correction subsystem 102. The specific structure of the data transmission module 202 can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0051] In one possible implementation, the data transmission module includes an optical fiber, a gigabit Ethernet communication interface converter, and an Ethernet cable; the optical fiber is connected to the gigabit Ethernet communication interface converter and the magnetic resonance compatible camera signal, respectively, and the Ethernet cable is connected to the gigabit Ethernet communication interface converter and the correction subsystem signal, respectively.

[0052] Taking Figure 2 above as an example, as shown in Figure 2, the data transmission module 202 includes an optical fiber 2021, a Gigabit Ethernet communication interface (GIGE) converter 2022, and an Ethernet cable 2023.

[0053] The optical fiber 2021 can be connected to both the magnetic resonance compatible camera 201 and the GIGE converter 2022, and can be used to transmit real-time image data acquired by the magnetic resonance compatible camera 201 to the GIGE converter 2022. Because optical fiber has advantages such as wide bandwidth, low transmission loss, and strong anti-interference capability, using optical fiber 2021 to realize data transmission between the magnetic resonance compatible camera 201 and the data transmission module 202 can reduce the impact of the magnetic resonance environment on the data transmission process and improve the reliability and stability of system 100. The specific type of optical fiber 2021 can be flexibly set according to actual usage requirements; for example, it can be set to multimode fiber, single-mode fiber, etc., and this disclosure does not specifically limit it in this regard.

[0054] GIGE is a camera interface standard developed based on the Gigabit Ethernet communication protocol. The GIGE converter 2022 enables fast image data transmission over long distances and has high hardware and software compatibility, improving the versatility of the data transmission module 202. The specific form of the GIGE converter 2022 can be found in related technical implementations, and this disclosure does not impose specific limitations on it.

[0055] Ethernet cable 2023 is connected to GIGE converter 2022 and correction subsystem 102 respectively, enabling real-time image data to be transmitted to correction subsystem 102. The specific type of Ethernet cable 2023 can be flexibly configured according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0056] In one possible implementation, the magnetically compatible optical imaging subsystem 101 further includes a power module, which includes a power supply, a power filter, a waveguide, and a power supply cable disposed within the waveguide.

[0057] Taking Figure 2 above as an example, as shown in Figure 2, the power supply module 203 can be electrically connected to the magnetic resonance compatible camera 201 and the data transmission module 202 respectively, and is used to supply power to the magnetic compatibility optical imaging subsystem 102.

[0058] The power module 203 includes a power supply 2031, a power filter 2032, a waveguide 2033, and a power supply cable 2034 disposed within the waveguide 2033.

[0059] The power supply filter 2032 can be used to reduce electromagnetic interference from the magnetic resonance environment on the power supply 2031 and reduce noise signals in the electrical signals input to the magnetic resonance compatible camera 201, ensuring the normal operation of the power supply 2031 and the magnetic resonance compatible camera 201, and improving the stability and reliability of the system 100. The specific form of the power supply filter 2032 can be found in related technical embodiments, and this disclosure does not impose specific limitations on it.

[0060] The waveguide 2033 can be used to suppress magnetic resonance radio frequency during electrical signal transmission and to attenuate and suppress gradient signals at a preset cutoff frequency, thereby reducing the impact of electromagnetic interference on electrical signal transmission and improving the stability and reliability of system 100. The specific form of the waveguide 2033 can be flexibly set according to actual usage requirements; for example, it can be a copper waveguide, etc., and this disclosure does not impose specific limitations. The preset cutoff frequency corresponding to the waveguide 2033 can be flexibly set according to actual usage requirements; for example, it can be set to 90dB, etc., and this disclosure does not impose specific limitations in this regard.

[0061] In one possible implementation, the correction subsystem 102 is used to: determine motion detection data corresponding to the target object based on multi-view real-time optical images; and perform motion artifact correction on the initial magnetic resonance image based on the motion detection data to determine an artifact-free magnetic resonance image.

[0062] The correction subsystem 102 can determine the motion detection data corresponding to the target object based on multi-view real-time optical images. The motion detection data can represent the positional changes, posture changes, and shape changes of the target object during magnetic resonance imaging. Its specific content can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it. The specific method by which the correction subsystem 102 determines the motion detection data corresponding to the target object can refer to the implementation methods in related technologies, and this disclosure does not impose specific limitations on it.

[0063] Based on motion detection data, the correction subsystem 102 can perform motion artifact correction on the initial magnetic resonance image to determine an artifact-free magnetic resonance image. The specific method by which the correction subsystem 102 performs motion artifact correction on the initial magnetic resonance image can be found in related technologies, and this disclosure does not impose specific limitations on it.

[0064] In one possible implementation, the target object corresponds to multiple reference marker points; the correction subsystem 102 is used to: determine the real-time position information corresponding to each reference marker point based on the multi-view real-time optical image; and determine motion detection data based on the real-time position information corresponding to each reference marker point.

[0065] The multiple reference markers corresponding to the target object can be pre-set on the target object or selected in a multi-view real-time optical image; this disclosure does not impose specific limitations on this. The specific number of reference markers can be flexibly set according to actual usage requirements, as long as it meets the needs of solving motion detection data; this disclosure does not impose specific limitations on this. Optionally, the number of reference markers is at least four.

[0066] The specific method by which the correction subsystem 102 determines the real-time location information corresponding to the reference marker point can be referred to the implementation methods in related technologies, and this disclosure does not make specific limitations on it.

[0067] In one example, the multi-view real-time optical image includes two real-time optical images from different perspectives. The correction subsystem 102 can perform binocular visual localization on any reference marker point based on the two real-time optical images from different perspectives to determine the real-time position information corresponding to the reference marker point.

[0068] Figure 3 illustrates a schematic diagram of position reconstruction according to an embodiment of the present disclosure. As shown in Figure 3, point O1 represents the geometric center of the magnetic resonance-compatible camera 201 corresponding to the first viewpoint; point O2 represents the geometric center of the magnetic resonance-compatible camera 201 corresponding to the second viewpoint. Point P represents any reference marker point corresponding to the target object; point P1 represents the position of the reference marker point in the real-time optical image of the first viewpoint; point P2 represents the position of the reference marker point in the real-time optical image of the second viewpoint.

[0069] A spatial rectangular coordinate system is constructed with point O1 as the origin and the direction of the line connecting points O1 and O2 as the x-axis. Based on the straight-line distance B between points O1 and O2, the coordinates of point O2 in this spatial rectangular coordinate system can be determined as (B, 0, 0).

[0070] For any real-time optical image from any viewpoint, a Cartesian coordinate system is constructed with the upper left boundary point of the real-time optical image as the origin, the direction of the line connecting the upper left and upper right boundary points as the x-axis, and the direction of the line connecting the upper left and lower left boundary points as the y-axis.

[0071] Based on the above, the spatial geometric relationship between point P1 and the magnetic resonance compatible camera 201 corresponding to the first viewpoint can be expressed as formula (1):

[0072] Among them, X L Y represents the x-coordinate of point P1 in the Cartesian coordinate system corresponding to the real-time optical image from the first perspective; L b represents the ordinate of point P1 in the Cartesian coordinate system corresponding to the real-time optical image from the first viewpoint; x1 b represents the optical center of the magnetic resonance-compatible camera 201 corresponding to the first-view perspective, and its x-coordinate in the Cartesian coordinate system corresponding to the real-time optical image from the first-view perspective; y1 f represents the optical center of the magnetic resonance-compatible camera 201 corresponding to the first-view perspective, and its ordinate in the Cartesian coordinate system corresponding to the real-time optical image from the first-view perspective; x1 This represents the focal length of the magnetic resonance-compatible camera 201 along the x-axis corresponding to the first-person viewpoint; f y1This represents the focal length of the magnetic resonance-compatible camera 201 in the y-axis direction corresponding to the first-person view; x p The x-coordinate of point P in the aforementioned rectangular coordinate system is represented by y. p This represents the ordinate of point P in the aforementioned Cartesian coordinate system; z p This represents the vertical coordinate of point P in the aforementioned spatial rectangular coordinate system.

[0073] The spatial geometric relationship between point P1 and the magnetic resonance compatible camera 201 corresponding to the second viewpoint can be expressed as formula (2):

[0074] Among them, X R Y represents the x-coordinate of point P2 in the Cartesian coordinate system corresponding to the real-time optical image from the second perspective; R This represents the ordinate of point P2 in the Cartesian coordinate system corresponding to the real-time optical image from the second perspective; b x2 b represents the optical center of the magnetic resonance-compatible camera 201 corresponding to the second viewpoint, and its x-coordinate in the Cartesian coordinate system corresponding to the real-time optical image of the second viewpoint; y2 f represents the optical center of the magnetic resonance-compatible camera 201 corresponding to the second viewpoint, and its ordinate in the Cartesian coordinate system corresponding to the real-time optical image from the second viewpoint; x2 This represents the focal length of the magnetic resonance-compatible camera 201 along the x-axis corresponding to the second-view perspective; f y2 This indicates the focal length of the magnetic resonance-compatible camera 201 in the y-axis direction corresponding to the second viewpoint.

[0075] Given that the magnetic resonance compatible camera 201 is the same for all viewpoints, it can be determined that b x1 =b x2 =b x b y1 =b y2 =b y f x1 =f x2 =f x and f y1 =f y2 =f y Based on this, by solving the system of equations (1) and (2) simultaneously, the coordinates of point P in the aforementioned spatial rectangular coordinate system can be expressed as equation (3):

[0076] Based on the real-time position information corresponding to each reference marker point, the correction subsystem 102 can construct the three-dimensional point cloud information corresponding to the target object, thereby accurately tracking the motion of the target object. Specifically, the real-time position information corresponding to each reference marker point can be used to determine the motion detection data corresponding to the target.

[0077] In one possible implementation, the correction subsystem 102 is used to: for any reference marker point, determine the motion information corresponding to the reference marker point based on the real-time position information corresponding to the reference marker point; and determine motion detection data based on the motion information corresponding to each reference marker point.

[0078] The motion information corresponding to any reference marker point can represent the positional change of that reference marker point during the movement of the target object. The specific content of the motion information can be flexibly set according to actual usage requirements, and this disclosure does not impose specific limitations on it.

[0079] The specific method by which the correction subsystem 102 determines the motion information corresponding to any reference marker point can be referred to the implementation methods in related technologies, and this disclosure does not make specific limitations on it.

[0080] In one example, for any reference marker point A corresponding to the target object, before the target object moves, its real-time position information may include the first spatial coordinate (X, Y, F, G) of reference marker point A in the aforementioned spatial rectangular coordinate system. A Y A Z A At time I after the target object begins to move, the real-time position information corresponding to reference marker A may include the second spatial coordinates (X, Y, X) of reference marker A in the aforementioned spatial rectangular coordinate system. I Y I Z I ).

[0081] Second spatial coordinates (X) I Y I Z I ) and the first spatial coordinate (X) A Y A Z A The relationship between the two can be expressed as formula (4):

[0082] Where R represents the rotational motion matrix corresponding to reference marker point A after the target object moves; T represents the translational motion matrix corresponding to reference marker point A after the target object moves.

[0083] Based on the transformation relationship of spatial coordinate systems, the coordinates of reference marker point A in the Cartesian coordinate system corresponding to the real-time optical image from any viewpoint can be compared with the second spatial coordinates (X... I Y I Z I The conversion relationship between them is expressed by formula (5):

[0084] Where K represents the intrinsic parameter matrix of the magnetic resonance-compatible camera 201 used to acquire real-time optical images from this viewpoint.

[0085] Simplifying by combining equations (4) and (5), we obtain equation (6):

[0086] The matrix operation result of the intrinsic parameter matrix K, the rotational motion matrix R, and the translational motion matrix T can be expressed as formula (7):

[0087] Then the aforementioned formula (6) can be transformed into formula (8):

[0088] Simplifying formula (8) yields formula (9):

[0089] According to formula (9), a set of equations can be constructed to solve for the motion information of each reference marker by combining the real-time position information corresponding to multiple reference markers. This set of equations can be expressed in matrix form as formula (10):

[0090] Among them, (X) i Y i Z i (x) represents the real-time position information of the i-th reference marker point in the aforementioned spatial rectangular coordinate system before the target object moves; (x) i y i , z i ) represents the coordinates of the i-th reference marker point in the Cartesian coordinate system corresponding to the real-time optical image from any viewpoint after the target object moves.

[0091] Since the rotational motion matrix R and the translational motion matrix T both have three degrees of freedom, the rotational motion matrix R and the translational motion matrix T can be determined by using formula (10) and the intrinsic parameter matrix K of the magnetic resonance compatible camera 201 used to acquire the real-time optical image from any three reference markers in the aforementioned spatial rectangular coordinate system and in any viewpoint, so as to represent the motion information corresponding to each reference marker.

[0092] Based on the motion information corresponding to each reference marker point, the correction subsystem 102 can determine the motion detection data corresponding to the target object. The specific method by which the correction subsystem 102 determines the motion detection data corresponding to the target object can be found in related technical implementations, and this disclosure does not impose specific limitations on it.

[0093] In one example, the motion information corresponding to each reference marker point can be transformed according to the transformation relationship of the spatial coordinate system to obtain the motion information of each reference marker point in the magnetic resonance imaging coordinate system, which can be used as the motion detection data corresponding to the target object.

[0094] In one possible implementation, the correction subsystem 102 is used to: perform dimensional transformation on the motion detection data to determine k-space motion data; correct the k-space motion data to determine corrected k-space motion data; and correct the initial magnetic resonance image based on the corrected k-space motion data to determine an artifact-free magnetic resonance image.

[0095] The motion detection data corresponding to the target object can describe the motion of the target object during the magnetic resonance imaging process from a time dimension. In order to correct the initial magnetic resonance image, the correction subsystem 102 needs to perform a dimensional transformation on the motion detection data, converting it to the k-space data phase encoding dimension to determine the corresponding k-space motion data. The specific method by which the correction subsystem 102 performs the dimensional transformation on the motion detection data can be referred to the implementation methods in related technologies, and this disclosure does not specifically limit it.

[0096] After determining the k-space motion data, the correction subsystem 102 can perform motion correction on the k-space motion data to determine the corrected k-space motion data with high accuracy, thereby ensuring the quality of the artifact-free magnetic resonance image obtained after subsequent correction. The specific method by which the correction subsystem 102 corrects the k-space motion data can be found in related technical implementations, and this disclosure does not impose specific limitations on it.

[0097] In one possible implementation, the k-space motion data includes: rotation trajectory data and translational motion data; the correction subsystem 102 is used to: perform angle correction on the rotation trajectory data to determine the corrected rotation trajectory data; and perform phase correction on the translational motion data to determine the corrected translational motion data.

[0098] Specifically, the motion of the target object can be decomposed into rotational motion and translational motion. Based on the motion detection data, the rotation matrix of the target object in the magnetic resonance imaging coordinate system can be determined as [R]. x R y R z Then, the rotation trajectory data of the target object in k-space can be expressed as formula (11): Traj after =R x ·R y ·R z ·Traj before (11)

[0099] Among them, Trajafter Traj represents the rotation trajectory data of the target object after it has moved. before This represents the rotation trajectory data of the target object before it moves.

[0100] The correction subsystem 102 can perform angle correction on the rotation trajectory data to determine the corrected rotation trajectory data. The corrected rotation trajectory can be expressed as formula (12):

[0101] On the other hand, based on the motion detection data, the displacement distance of the target object along the x-axis in the magnetic resonance imaging coordinate system can be determined as Δx, the displacement distance along the y-axis as Δy, and the displacement distance along the z-axis as Δz. Then, the translational motion data of the target object in k-space can be expressed as formula (13):

[0102] Among them, K after (x0, y0, z0) represents the value at coordinates (x0, y0, z0) in the k-space after the target object has moved; K before (x0, y0, z0) represents the value at coordinates (x0, y0, z0) in k-space before the target object moves.

[0103] The correction subsystem 102 can perform phase correction on the translational motion data to determine the corrected translational motion data. The corrected translational motion data can be expressed as formula (14):

[0104] Based on the corrected k-space motion data, the correction subsystem 102 can correct the initial magnetic resonance image to determine an artifact-free magnetic resonance image. The specific method by which the correction subsystem 102 corrects the initial magnetic resonance image can be found in related art implementations, and this disclosure does not impose specific limitations on it.

[0105] In one example, when the scanning trajectory of magnetic resonance imaging is a radial trajectory, the correction subsystem 102 can perform gridded interpolation on the corrected k-space data and use a non-uniform inverse Fourier transform reconstruction method to correct the initial magnetic resonance image based on the motion-corrected k-space data to determine an artifact-free magnetic resonance image.

[0106] The motion artifact correction system for magnetic resonance imaging (MRI) according to this disclosure includes a magnetically compatible optical imaging subsystem and a correction subsystem. The magnetically compatible optical imaging subsystem can be placed in the same MRI environment as the target object, thereby providing it with a better field of view. During MRI of the target object, it can accurately track the target object's motion in real time, determine the corresponding multi-view real-time optical image, ensure the effectiveness and reliability of the multi-view real-time optical image, and reduce the impact on the MRI process, exhibiting high versatility and accuracy. The correction subsystem can correct motion artifacts in the initial MRI image corresponding to the target object obtained from the multi-view real-time optical image, determining the artifact-free MRI image of the target object, thus improving the quality and reliability of the artifact-free MRI image.

[0107] It should be noted that although Figures 1 and 2 are used as examples to illustrate the motion artifact correction system for magnetic resonance images, those skilled in the art will understand that this disclosure is not limited thereto. In fact, users can flexibly set the specific structure of the magnetic resonance image according to their personal preferences and / or actual application scenarios, as long as the motion artifact correction of the magnetic resonance image can be achieved based on the above process.

[0108] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A motion artifact correction system for magnetic resonance imaging, characterized in that, include: A magnetically compatible optical imaging subsystem and a correction subsystem, wherein the magnetically compatible optical imaging subsystem and the target object are in the same magnetic resonance environment; The magnetically compatible optical imaging subsystem is used to determine the multi-view real-time optical image of the target object during the magnetic resonance imaging process of the target object; The correction subsystem is used to perform motion artifact correction on the initial magnetic resonance image corresponding to the target object obtained by magnetic resonance imaging based on the multi-view real-time optical image, and determine the artifact-free magnetic resonance image corresponding to the target object.

2. The system according to claim 1, characterized in that, The magnetically compatible optical imaging subsystem includes: multiple magnetic resonance compatible cameras and a data transmission module, wherein different magnetic resonance compatible cameras are set at different locations in the magnetic resonance environment; Any magnetic resonance compatible camera is used to determine the real-time optical image of the target object from the viewpoint corresponding to the magnetic resonance compatible camera. The data transmission module is used to transmit the multi-view real-time optical image to the correction subsystem.

3. The system according to claim 2, characterized in that, Any magnetic resonance compatible camera includes a monocular camera and a magnetically shielded housing.

4. The system according to claim 2, characterized in that, The data transmission module includes optical fiber, gigabit Ethernet communication interface converter, and Ethernet cable; The optical fiber is connected to the gigabit Ethernet communication interface converter and the magnetic resonance compatible camera signal, respectively, and the Ethernet cable is connected to the gigabit Ethernet communication interface converter and the correction subsystem signal, respectively.

5. The system according to claim 2, characterized in that, The magnetically compatible optical imaging subsystem also includes a power module, which includes a power supply, a power filter, a waveguide, and a power supply cable disposed within the waveguide.

6. The system according to any one of claims 1 to 5, characterized in that, The correction subsystem is used for: Based on the multi-view real-time optical images, determine the motion detection data corresponding to the target object; Based on the motion detection data, motion artifact correction is performed on the initial magnetic resonance image to determine the artifact-free magnetic resonance image.

7. The system according to claim 6, characterized in that, The target object corresponds to multiple reference marker points; The correction subsystem is used for: Based on the multi-view real-time optical images, determine the real-time position information corresponding to each reference marker point; The motion detection data is determined based on the real-time position information corresponding to each reference marker point.

8. The system according to claim 7, characterized in that, The correction subsystem is used for: For any reference marker, determine the motion information corresponding to the reference marker based on the real-time position information of the reference marker. The motion detection data is determined based on the motion information corresponding to each reference marker point.

9. The system according to claim 6, characterized in that, The correction subsystem is used for: The motion detection data is dimensionally transformed to determine k-space motion data; The k-space motion data is corrected to determine the corrected k-space motion data; Based on the corrected k-space motion data, the initial magnetic resonance image is corrected to determine the artifact-free magnetic resonance image.

10. The system according to claim 9, characterized in that, The k-space motion data includes: rotation trajectory data and translational motion data; The correction subsystem is used for: The rotation trajectory data is angle-corrected to determine the corrected rotation trajectory data; The translational motion data is phase-corrected to determine the corrected translational motion data.

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