Positioning of radio frequency coils in magnetic resonance imaging devices

Abstract

The invention relates to a system (1) for magnetic resonance imaging, the system comprising a magnetic resonance imaging device (2) and a control unit (3) configured to control the magnetic resonance imaging device (2), wherein the magnetic resonance imaging device (2) comprises a magnetic resonance bore (4), a movable table (5) configured to be movable into and out of the magnetic resonance bore (4), and at least two surface coils (24) comprising coil elements (26), the two surface coils (24) being configured to be positioned adjacent to each other on the movable table (5) with a relative overlap, such that at least one coil element of a first surface coil overlaps with a coil element of a second surface coil. Each of the at least two surface coils (24) comprises a housing (25), an inner core (26) configured to be two-dimensionally laterally slidable within the housing (25), the inner core corresponding to the coil element (26), and an actuator (27). The control unit (3) comprises a coil element detection unit (31) configured to detect the at least two coil elements (26), an overlap detection unit (32) configured to detect the relative overlap (R) of the at least two coil elements (26), a determination unit (33) configured to determine whether the detected relative overlap (R) is within a predefined critical range, and a position adjustment unit (34) configured to adjust the relative position of the coil elements (26) by controlling the respective actuator when the detected relative overlap (R) is outside the predefined critical range. The invention further relates to a method (100) for generating an image by magnetic resonance imaging and to a program unit.

Description

Technical Field

[0001] The present invention relates to a system for magnetic resonance imaging, a method for generating images by magnetic resonance imaging, and a program unit. Background Technology

[0002] High patient throughput is crucial for magnetic resonance imaging (MRI) equipment, especially in medical facilities. Therefore, ensuring a smooth imaging process is of paramount importance.

[0003] In magnetic resonance imaging (MRI) equipment, radio frequency (RF) coils are commonly used. These coils are configured to excite magnetization by broadcasting radio frequency power and to receive signals from the excited spins. Therefore, the RF coil directly affects the spatial and temporal resolution, sensitivity, and homogeneity in MRI. Consequently, proper positioning of the receiving coil is crucial for good image quality. For this reason, typically only trained and experienced personnel are permitted to operate MRI equipment. Staff shortages (e.g., due to illness, vacation, etc.) and / or operation of MRI equipment by unskilled personnel can lead to cancellations and / or delays in planned schedules. Therefore, workflows are becoming increasingly autonomous and automated, where proper coil positioning is of paramount importance.

[0004] Wireless radio frequency coil technology offers convenient and simple operation for coil handling and positioning, especially for increasingly autonomous and automated workflows. However, these increasingly autonomous and automated workflows also increase the challenge of ensuring sufficiently good and consistent image quality. Summary of the Invention

[0005] Therefore, improvements may be needed in the positioning of coils within magnetic resonance imaging equipment, particularly in autonomous and automated workflows. The object of the invention is addressed by the subject matter of the independent claims, wherein further embodiments are included in the dependent claims.

[0006] According to a first aspect, a system for magnetic resonance imaging is provided. The system includes a magnetic resonance imaging apparatus and a control unit configured to control the magnetic resonance imaging apparatus. The magnetic resonance imaging apparatus includes a magnetic resonance chamber, a movable stage configured to be able to move into and out of the magnetic resonance chamber, and at least two coil elements of at least one coil. The two coil elements are configured to be positioned adjacent to each other on the movable stage with relative overlap and are movable relative to each other on the movable stage. The control unit includes: a coil element detection unit configured to detect the at least two coil elements; an overlap detection unit configured to detect the relative overlap of the at least two coil elements; a determination unit configured to determine whether the detected relative overlap is within a predefined critical range; and a position adjustment unit configured to adjust the relative position of the coil elements when the detected relative overlap is outside the predefined critical range.

[0007] Such a system for magnetic resonance imaging (MRI) allows for the autonomous detection and guidance of optimal relative overlap between at least two coil elements. Optimal relative overlap can be defined as a value within a so-called "critical range" that allows for rapid image reconstruction and good image quality. The critical range can be defined by preset lower and upper limits, providing uniform B1 sensitivity and a good signal-to-noise ratio between these limits. The predefined critical range can be stored in the control unit.

[0008] Uniform B1 sensitivity defines the magnetic field sensitivity of the reconstructed image. The uniformity of the magnetic field is directly proportional to the intensity variation in the image (which means the pixel values ​​in the image). Local variations in B1 (meaning variations in pixel values ​​in the image) can lead to undesirable spatial variations in the image signal and contrast. Therefore, the more uniform the B1 sensitivity, the better the image quality.

[0009] A good signal-to-noise ratio (SNR) can be defined as the independence of noise from different coil elements, which can be achieved within a predefined critical range. The SNR can be determined using a noise correlation matrix.

[0010] Image quality depends on the number of artifacts present. Artifacts may occur due to the patient's breathing and / or blood vessels. Therefore, these artifacts are almost unavoidable. Additionally, an unfavorable signal-to-noise ratio (SNR) can also contribute to artifacts. The SNR corresponds to a measurable value of the presence and intensity of noise due to unwanted signal correlation caused by adjacent coil elements. Within a predefined critical range, the SNR approaches an optimal value that defines the minimum impact on image quality.

[0011] The movable worktable used herein should be understood as a worktable or working bed on which the patient is placed, at least for the duration of the magnetic resonance image generation process, and the movable worktable may also be referred to as a patient table. The movable worktable may include at least one coil (preferably several coils) embedded in the surface of the worktable bed. The embedded coils may be selectively tuned or detuned by a control unit to achieve an optimal arrangement for the image generation process to be performed.

[0012] The at least one coil may be a receiving coil typically placed on the patient's body. Additionally or alternatively, there may be applications where relative overlap of transmitting coils and / or combinations of transmitting and receiving coils can be used. A coil may include at least one coil segment comprising several coil elements. The coil elements of a coil segment may be pre-fixed relative to each other such that signal interference between adjacent coil elements is very low, resulting in minimal impact on image quality.

[0013] At least two coil elements of at least one coil may involve coil elements arranged in the outer edge region of at least one coil. The coil setup may depend on the region to be imaged and / or independently selected anatomical structures, as well as coil size and / or patient body size.

[0014] The position adjustment unit used herein should be understood to include audio guidance and / or video guidance, as well as automatic positioning. In other words, the position adjustment unit can be configured to support manual adjustment of the coil position, for example, by a patient providing audio guidance (e.g., by outputting a position adjustment command via audio) and / or optical guidance (e.g., by displaying the requested coil displacement, by showing the actual coil position and the requested coil position). Alternatively or additionally, the position adjustment unit can be configured to automatically adjust the coil position without human intervention. In this case, the coil can be provided with a software-controlled actuator controlled by the position adjustment unit.

[0015] In addition, the control unit (especially the position adjustment unit) can be configured to automatically select and detune individual coil elements (especially individual coil elements of the radio frequency coil) to achieve relative overlap within a predefined critical range.

[0016] Therefore, this system allows for patient participation, such as through the patient's own self-preparation, without the need for an experienced staff member present. The system can guide the patient through the preparation process (e.g., including the selection and positioning of the correct coil) so that the relative overlap remains within a predefined critical range.

[0017] In other words, systems for magnetic resonance imaging can allow for increased patient throughput because performance is at least less dependent on the presence of skilled personnel. Furthermore, by adjusting the relative overlap of adjacent overlapping coil elements to a position where the signal-to-noise ratio has little impact on image quality, the system can allow for improved image quality.

[0018] Additionally, a magnetic resonance imaging (MRI) device may include a computing unit configured to perform an image generation process. In such a case, a control unit configured to control the MRI device controls the computing unit used to perform the image generation process.

[0019] The control unit can be a state machine capable of machine learning. Machine learning corresponds to a computer-implemented method for accessing and / or collecting data and using that data to learn from itself. Therefore, machine learning is an application of artificial intelligence (AI) that enables a system to automatically learn and improve based on experience (e.g., based on collected data) without explicit programming. The control unit can use data from, for example, coil element detection units, overlap detection units, determination units, and / or position adjustment units. Additionally, the control unit can access hospital and / or patient databases.

[0020] According to an embodiment, the at least two coil elements may come from different coils. There may be applications requiring the use of more than one coil. To ensure seamless imaging, at least two coils should be positioned to overlap each other. In such cases, coil elements arranged in the outer edge regions of each coil can be positioned to overlap each other. In the case of a single coil, the coil may be flexible and wrapped around a part of the patient's body (e.g., the knee), and coil elements in the opposite outer edge regions of the coil can be positioned to overlap each other.

[0021] According to another embodiment, the at least one coil may be in the form of a thin, flat, blanket-like pad. Such a coil can be flexible in shape, allowing it to be wrapped around a part of the patient's body as described above. For other applications, such a coil may be laid flat on a part of the patient's body (e.g., the hips, neck, or chest). Additionally, other coil types may be used, such as volumetric coils, surface coils, etc.

[0022] According to an embodiment, at least one coil may be wireless or non-wireless.

[0023] Non-wireless coils may include connecting wires to connect the coil to an interface of a control unit or computing unit. Non-wireless coils may include more than one coil segment to cover an entire body area; for example, a coil covering the leg may include two coil segments. One coil segment may be configured to be placed on the thigh, and another coil segment may be configured to be placed on the calf, wherein both coil segments may be positioned to overlap each other at the knee. Such coil segments can be at least partially pre-arranged because all coil segments can be connected to the same connecting wire. Wireless coils can simplify coil handling, especially when placed by inexperienced individuals (e.g., the patient themselves or an unskilled operator for autonomous image acquisition).

[0024] According to an embodiment, the coil element detection unit may include at least one sensor configured to detect a mark on the coil. The sensor is selected from a 2D sensor group consisting of optical video sensors, capacitive sensors, and inductive sensors, or from a 3D video sensor group consisting of radar sensors, lidar sensors, and infrared sensors.

[0025] The coil (particularly a non-wireless coil) may include optical markers, which can be optical, capacitive, or inductive, and can be sensed by a corresponding sensor of the coil element detection unit. The markers may have predefined positions on the corresponding coil, such that the markers detected by the coil element detection unit provide guidance for achieving relative overlap within a predefined critical range. Additionally or alternatively, the coil (particularly a wireless RF coil) may be equipped with a color / sensor-coded area to support guidance for achieving relative overlap within a predefined critical range. Furthermore, an audio device can be independently activated to support optical guidance.

[0026] When a 3D video sensor is used for guidance based on an external 3D sensor to achieve relative overlap within a predefined critical range, the coil may include individual passive or active markers (e.g., regions) to provide contrast for detection using the 3D video sensor. Active markers can be modulated and detected by their correlation with a reference signal, allowing the active markers to operate with extremely low power requirements.

[0027] According to an embodiment, the at least one coil may include a sensing flexible region. The flexible region may be stretchable. By stretching the flexible region of the coil, the relative overlap between the coil and adjacently positioned coils can be adjusted, particularly through sensing integrated within the flexible region. The flexible region may have markings configured to change their distance according to stretching. Sensing techniques integrated within the stretchable region can provide measurement signals for detecting relative overlap.

[0028] Alternatively, the flexible area can be configured as a flexible latch or strip containing flexible coil conductors or coil electronics to guide and adjust relative overlap. When relative overlap is detected within a predefined critical range, a mechanical latch (e.g., a Velcro, groove, or retaining clip) can be used to secure the relative overlap. The flexible area may include a mark to be sensed by the coil element detection unit. In such a case, the stretchable area may include coil conductors or coil electronics.

[0029] According to an embodiment, the magnetic resonance imaging apparatus may further include at least one coil holder configured to hold the at least one coil in a predefined position.

[0030] The coil holder can be fabricated for adhesion to clothing or can be an attachment. The coil can be secured to the coil holder, which preferably has securing devices and markings for individual coil positioning detection. The coil holder and / or the coil can be equipped with sensing technology to detect relative overlap within a predefined critical range based on the patient's individual body shape. The coil holder can also be configured to hold at least one coil in place during the image generation process to prevent coil displacement (particularly displacement that causes relative overlap to move outside the predefined critical range). The coil holder can be applied to both wireless and non-wireless coils and can be combined with all the positioning guidance techniques mentioned above.

[0031] The coil includes a housing and an inner core, the inner core being configured to slide laterally in two dimensions within the housing.

[0032] The coil can be a surface coil, which can be manually applied to the patient in approximately the correct position, and then, for example, the patient can fix the surface coil themselves. The inner core includes coil elements and is moved relative to the housing by, for example, an integrated software-controlled actuator. The inner core is movable in two lateral plane dimensions of the surface coil to achieve relative overlap within a predefined critical range. Such coils are particularly useful when placed under the patient's body or for coils integrated into a movable worktable.

[0033] In an embodiment, the at least one coil may further include at least one actuator configured to move the inner core between at least a first position without relative overlap and a second position having said relative overlap.

[0034] According to an embodiment, the at least one actuator may be coupled to the control unit, which is configured to control the actuator to move the inner core. The actuator may be driven electrically, pneumatically, or similarly. The actuator itself may have monitoring devices (e.g., sensors for displacement measurement) and / or be monitored and / or controlled by another monitoring component of the system.

[0035] According to a second aspect, a method for generating images via magnetic resonance imaging is provided. The method includes the steps of: positioning at least two coil elements of at least one coil on a movable stage (preferably on a patient lying on the movable stage) with relative overlap; detecting the relative overlap of the coil elements; determining whether the detected relative overlap is within a predefined critical range; repeating the aforementioned steps when the detected relative overlap is outside the predefined critical range; and initiating an image generation process when the detected relative overlap is within the predefined critical range and the movable stage is in a final position for generating images. The method can be implemented at least partially by a computer and can be implemented in software and / or hardware.

[0036] This method allows for the autonomous detection and guidance of at least two coil elements to achieve optimal relative overlap. Therefore, it allows for patient participation, such as through the patient's own self-preparation, without the need for an experienced staff member present. The method guides the operation of the patient-positioning coils so that the relative overlap remains within a predefined critical range. Thus, it enables automated and autonomous MRI image acquisition processes, ensuring good image quality.

[0037] According to an embodiment, the method may further include the following steps: monitoring the relative overlap of the coil elements during the image generation process; and repositioning the coil elements during the image generation process when the monitored relative overlap is detected to be outside the predefined critical range.

[0038] Monitoring the relative overlap of coil elements during image generation allows for the detection of any changes in the relative overlap and thus a timely response to such changes. Repositioning of coil elements during image generation may only be applicable when using coils configured for automatic positioning by the position adjustment unit, as patient movement may not be permitted during the image generation process.

[0039] Otherwise, the impact of the relative overlap caused by the shift on the image quality can be estimated, and if necessary, the image generation process can be stopped early, the coil elements can be manually repositioned, and the image generation process can be restarted from scratch.

[0040] According to an embodiment, the step of detecting the relative overlap of the coil elements may include determining a noise correlation matrix.

[0041] The noise correlation matrix is ​​a measurement of the signal-to-noise ratio. It can be obtained by measuring the electrical signals of individual coil elements. Alternatively, it can be estimated using AI algorithms in the control unit, external 3D sensing, or sensing within the coil itself.

[0042] The noise correlation matrix can preferably be determined using local and / or distributed transmitters located in a movable stage, within the coil itself, or within the bore of the MR system. When using a wireless coil, the noise correlation matrix and / or signal coupling can be determined by an individual digital transceiver located within the wireless coil. Different coil elements can be independently activated to detect relative overlap and generate corresponding feedback signals for coil positioning guidance as described above.

[0043] According to an embodiment, the step of determining whether the detected relative overlap is within a predefined critical range may include: comparing the measured noise correlation matrix with a predefined noise correlation matrix threshold, and determining whether the detected relative overlap is within the predefined critical range based on the comparison result.

[0044] The predefined noise correlation matrix threshold can vary depending on the region to be imaged. This predefined noise correlation matrix can be stored in the control unit and adjusted by the control unit through a machine learning process.

[0045] According to an embodiment, the step of locating the at least two coil elements may further include: detecting a mark provided on the coil or coil holder, thereby providing visual and / or auditory guidance for manual positioning of the coil elements to a position corresponding to a relative overlap within the predefined critical range based on the position of the detected mark.

[0046] Visual and / or auditory guidance can support manual positioning of coil elements, thereby accelerating the positioning process.

[0047] According to an embodiment, the step of locating at least two coil elements of at least one coil may further include: automatically locating the at least one coil based on at least one software-controlled mechanism integrated in the coil.

[0048] Automatic coil positioning via a software-controlled mechanism can include a surface coil with a housing and an inner core, wherein, as outlined above, the inner core is movable within the housing. Another software-controlled mechanism for automatic coil positioning can include a coil equipped with a crawling mechanism that allows the coil to crawl across a patient, for example, guided by a position adjustment unit. Once the correct position is reached, the coil can be secured in place, for example, by the patient.

[0049] The crawling mechanism can be implemented based on the conservation of inertia. For example, some relatively large mass inside the coil can first be rapidly pulled laterally to one side by the actuator, and then slowly moved back. Conservation of inertia allows the coil to move during the rapid motion because it may exceed the frictional force between the coil and the patient. During the slower return motion, the frictional force may not be exceeded, thus keeping the coil in place. In other words, the rapid movement and slow return of the mass is a rapid repetition but with a slow amplitude, which can effectively make the coil crawl along the patient's body.

[0050] According to an embodiment, the method may further include the step of moving the movable worktable to the final position, wherein the movable worktable is moved to the final position after the detected relative overlap is determined to be within the predefined critical range, or after necessary steps have been performed to achieve the relative overlap within the predefined critical range. Specifically, when using a wireless coil, the worktable can be moved to the final position during coil positioning to achieve the relative overlap within the predefined critical range.

[0051] According to a third aspect, a program unit is provided, the program unit being configured to be stored on a control unit of a system according to a first aspect, and configured to cause the system to operate the method according to a second aspect.

[0052] Note that regardless of the aspects involved, the above embodiments can be combined with each other. Therefore, the method can be combined with the structural features of the system in other aspects, and similarly, the system can be combined with the features described above regarding the method. Advantageously, the benefits provided by any of the above aspects and examples are equally applicable to all other aspects and examples, and vice versa.

[0053] These and other aspects of the invention will become apparent and elucidated with reference to the embodiments described below. Attached Figure Description

[0054] Exemplary embodiments of this disclosure will be described in the following figures.

[0055] Figure 1 A schematic top view of an exemplary embodiment of a system for magnetic resonance imaging is shown.

[0056] Figure 2 A schematic diagram of an exemplary arrangement of several coils is shown to illustrate exemplary extreme values ​​of a predefined critical range.

[0057] Figure 3 A schematic cross-sectional view is shown of an exemplary arrangement of two coils with relative overlap within a predefined critical range. Figure 3 a), and a schematic diagram of an exemplary arrangement of two coils with arbitrary relative overlap ( Figure 3 b).

[0058] Figure 4 A schematic cross-sectional view of an exemplary embodiment of a coil wound around a knee is shown.

[0059] Figure 5 Several schematic and exemplary arrangements of coils for achieving relative overlap are shown.

[0060] Figure 6 A schematic diagram of an exemplary embodiment of the illustrated surface coil is shown.

[0061] Figure 7 A schematic flowchart of an exemplary method for generating images via magnetic resonance imaging is shown.

[0062] The accompanying drawings are merely illustrative and are used only to illustrate embodiments of the invention. In principle, identical or equivalent elements are provided with the same reference numerals.

[0063] List of reference numerals in the attached diagram:

[0064] 1 System

[0065] 2. Magnetic Resonance Imaging Equipment

[0066] 3 Control Unit

[0067] 4. Magnetic Resonance Chamber

[0068] 5. Movable worktable

[0069] 6 patients

[0070] 7 coils

[0071] 8. Head coil

[0072] 9. Shoulder coil

[0073] 10 Neck Coil

[0074] 11 First front coil

[0075] 12 Second front coil

[0076] 13 Leg coils

[0077] 14 Upper body segments

[0078] 15. Coil Components

[0079] 16. Coil body

[0080] 17. Overlapping Area

[0081] 18 External coil components

[0082] 19 knees

[0083] 20 latches

[0084] 21 Sensing Technology

[0085] 22 Volume Coil

[0086] 23 Stretchable Zone

[0087] 24 Surface Coils

[0088] 25. Outer shell

[0089] 26 inner cores

[0090] 27 Actuator

[0091] 31 Coil Component Detection Unit

[0092] 32 overlap detection units

[0093] 33. Determine the unit

[0094] 34 Position Adjustment Units

[0095] 100 methods

[0096] R relative overlap

[0097] R' Effective relative overlap

[0098] R1 lower limit

[0099] R2 upper limit Detailed Implementation

[0100] Figure 1 An exemplary embodiment of a system 1 for magnetic resonance imaging is shown in the schematic diagram. System 1 includes a magnetic resonance imaging device 2 and a control unit 3, wherein the control unit 3 is configured to control the magnetic resonance imaging device 2.

[0101] The magnetic resonance imaging device 2 includes a magnetic resonance chamber 4, a movable stage 5 configured to transport a patient 6 into and out of the magnetic resonance chamber 4, and several coils 7. Figure 1The diagram illustrates, exemplarily and schematically, a head coil 8, two shoulder coils 9, a neck coil 10, a first anterior coil 11, a second anterior coil 12, and two leg coils 13. Several coils 7 can be grouped, as exemplarily shown by an upper body segment 14 including the head coil 8, two shoulder coils 9, and neck coil 10. The combination of coils 7 can be selected based on the region to be imaged and / or independently chosen anatomical structures.

[0102] Each coil 7 includes a plurality of coil elements 15, which are fixedly arranged together to form a coil body 16 (see, for example, [link to coil body 16]). Figure 2 ).like Figure 1 As shown, the arrangement of coils 7 illustrates the overlapping region 17, in which adjacent coils 7 overlap each other. Within the overlapping region 17, the coil elements 15 of adjacent coils 7 are positioned to overlap each other. This relative overlap R of adjacent coil elements 15 (see, for example, see...) Figure 2 Noise can be generated due to the inductive coupling signal of adjacent coil elements 15. This noise directly affects the quality of the reconstructed image of the magnetic resonance imaging device 2. There exists a critical range within which the relative overlap R provides uniform B1 sensitivity and prevents the signal-to-noise ratio from decreasing, thereby achieving good image quality.

[0103] However, if the relative overlap R is too large or too short (meaning the relative overlap is outside the critical range), then the adjacent coil elements 15 are not optimally decoupled by inductance, resulting in signal-to-noise ratio loss and causing image artifacts that depend on the image sequence and image reconstruction algorithm.

[0104] Additionally, movement of the patient 6 and / or coil 7 during image generation can negatively impact image reconstruction, but this is difficult to prevent. Combined with situations where relative overlap is outside a critical range, image reconstruction can become even more complex, leading to poorer image quality.

[0105] The control unit 3 includes a coil element detection unit 31, an overlap detection unit 32, a determination unit 33, and a position adjustment unit 34.

[0106] The coil element detection unit 31 is configured to detect adjacent overlapping coil elements 15. The overlap detection unit 32 is configured to detect the relative overlap R of adjacent overlapping coil elements 15. These two units 31 and 32 can be provided separately or integrated together.

[0107] Coil element 15 can be detected by a mark (not shown) provided on coil 7. Coil element detection unit 31 and / or overlap detection unit 32 are capable of sensing the mark. Coil element detection unit 31 and overlap detection unit 32 can include 2D sensing technology (sensing optical, capacitive or inductive marks) and / or external 3D sensing technology (detecting passive or active marks that provide a contrast area, which can be detected by 3D sensing technology (e.g., radar, lidar or infrared sensor)).

[0108] The determining unit 33 is configured to determine whether the detected relative overlap R detected by the overlap detection unit 32 is within a critical range, for example by determining the actual noise correlation matrix and comparing the actual noise correlation matrix with a predefined noise correlation matrix threshold to determine whether the detected relative overlap R is within the critical range based on the comparison result. Alternatively or additionally, the determining unit 33 may determine whether the detected relative overlap R is within the critical range based on the result of the overlap detection unit 32.

[0109] The position adjustment unit 34 is configured to adjust the relative position of adjacent overlapping coil elements 15 when the detected relative overlap R is outside a critical range. The position adjustment unit 34 may include an audio guidance device and / or a video guidance device (not shown) to support manual adjustment of the coil position, for example, performed by the patient 6. The audio guidance device may provide audio guidance (e.g., by outputting a position adjustment command via audio), and / or the video guidance device may provide optical guidance (e.g., by displaying the desired displacement of the coil 7, or by displaying the actual position and desired position of the coil 7).

[0110] Alternatively or additionally, the position adjustment unit 34 may include an automatic positioning device configured to automatically adjust the position of the coil 7 without manual intervention. In this case, the coil 7 may be provided with a software-controlled actuator controlled by the position adjustment unit 34.

[0111] Additionally or alternatively, the position adjustment unit 34 can be configured to automatically select and detun individual coil elements 15 (especially coil 7 as a radio frequency coil) to achieve relative overlap R within a predefined critical range.

[0112] Figures 2 to 6 Several exemplary embodiments are shown, in which coils 7 are arranged to achieve relative overlap within a critical range.

[0113] exist Figure 2In this configuration, three coils 7 are arranged such that coil elements 15 disposed in the outer edge region of coil 7 are positioned to overlap each other, wherein each coil 7 is formed as a thin, flat, blanket-like pad. The thin, flat, blanket-like coil 7 can be formed by arranging the coil elements 15 in an array (not shown), wherein these arrays are fixedly arranged adjacent to each other to form coil 7. Figure 2 Each of the coil elements 15 shown corresponds to one coil element 15 in a coil element array. The relative overlap R1 between the first pair of overlapping coils 7 illustrates the lower limit of the critical range, while the relative overlap R2 between the second pair of overlapping coils 7 illustrates the upper limit of the critical range. They define the range in which the relative overlap R does not negatively affect image reconstruction.

[0114] Whether the relative overlap R is within the critical range can be determined by determining the noise correlation matrix. An individual digital transceiver (not shown) located in coil 7 is able to measure the noise correlation matrix and thus the signal coupling of adjacent overlapping coil elements 15.

[0115] Figure 3 A schematic cross-sectional view is shown of an exemplary arrangement of two coils 7 arranged with relative overlap R. Each coil 7 includes four arrays of coil elements 15 fixedly arranged and embedded in a coil body 16. The coils 7 are formed as wireless radio frequency coils. Figure 3 In a, the relative overlap R is within the critical range, while... Figure 3 In b, the relative overlap R is too large. The coil element 15 of the wireless RF coil is configured to be independently tuned, so that in Figure 3 In b, effective relative overlap R' can be achieved by detuning or deactivating the external coil element 18 of the upper coil 7 or the external coil element 18 of the lower coil 7.

[0116] Figure 4 The image shows the entanglement around patient 6 (see...) Figure 1 A schematic cross-sectional view of an exemplary embodiment of the coil 7 on the knee 19 of the patient. The coil 7 corresponds to a wireless radio frequency coil comprising an array of twelve fixedly arranged coil elements 15 integrated within a coil body 16. In this illustrated embodiment, the coil elements 15 of only one coil 7 are arranged adjacent to each other in an overlapping manner. Similar to... Figure 3 B, depending on the size of the relative overlap R caused by the coil wound around the knee 19, one or more coil elements 15 can be deactivated to achieve relative overlap R within a critical range.

[0117] Figure 5 An overview of several schematic and exemplary arrangements of coil 7 is shown, which are used to achieve relative overlap R using different mechanical mechanisms, particularly suitable for use by control unit 3 (see...). Figure 1The autonomous positioning and imaging of coil 7 are as follows: Figure 7 As further described.

[0118] Figure 5 a shows a schematic side view of two adjacently arranged coils 7, while Figure 5 b shows the corresponding top view. According to this exemplary embodiment, the relative overlap R between two adjacently arranged coils 7 is achieved by providing a flexible and / or stretchable latch 20. By stretching the latch 20 of one coil 7 over the adjacently arranged coils 7, the relative overlap R can be generated and aligned to a critical range. For this purpose, the latch 20 includes markings (not shown) that change their distance according to stretching. Therefore, it is used as sensor technology 21 (see...) Figure 5 c) The markings can provide a measurement signal, which can be detected by the coil element detection unit 31 and / or the overlap detection unit 32 and / or the determination unit 33. Based on the detected signal and the determined relative overlap R, the position adjustment unit 34 adjusts the position of the latch 20 until the relative overlap R is within the critical range.

[0119] Figure 5 c shows a cross-sectional view of two adjacent overlapping coils 7, each coil including integrated sensing technology 21 to align the relative overlap R within a critical range.

[0120] Figure 5 d basically combines Figure 4 and Figure 5 a and Figure 5 Features of the embodiment shown in b. The coil 7, which allows it to be wound around the patient's body 6, can also be stretchable to achieve the relevant overlap R within a critical range.

[0121] Figure 5 e illustrates an exemplary embodiment of the combination of the illustrated volumetric coil 22 and the thin, flat, blanket-like coil 7. The flat coil 7 may include a stretchable region 23 (see [link to documentation]). Figure 5 f). Both coils 7 and 22 include integrated sensing technology 21 to align the relative overlap R within a critical range.

[0122] Figure 5 f shows a schematic diagram of an exemplary embodiment of a flat-shaped coil 7, which includes a stretchable region 23 on the surface of the coil 7. The stretchable region 23 includes a mark (not shown) configured to be sensitive to 3D sensing technology (e.g., provided by the coil element detection unit 31 and / or the overlap detection unit 32).

[0123] Figure 6A schematic diagram of an exemplary embodiment of the illustrated surface coil 24 is shown. The surface coil 24 includes a housing 25, an inner core 26, and an actuator 27. The inner core 26 corresponds to a coil element 15 disposed inside the housing 25 and movable relative to the housing 25. The inner core 26 is moved by the actuator 27, which can be controlled, for example, by a position adjustment unit 34 of the control unit 3. The actuator 27 is controlled such that the inner core 26 of the overlapping surface coil 24, which is arranged without relative overlap, is positioned relative to the inner core 26 of the overlapping surface coil 24. Figure 6 a) is moved to achieve a relative overlap R between the inner cores 26, the relative overlap R being within a critical range (see...). Figure 6 b).

[0124] Figure 7 A schematic flowchart of an exemplary method 100 for generating an image via magnetic resonance imaging is shown. The method 100 for generating an image via magnetic resonance imaging includes the following steps, the order of which is not mandatory but preferred. In step S1, markings provided on a coil 7 or coil holder (not shown) are detected, for example, by a coil element detection unit 31 and / or a position adjustment unit 34, to position at least two coil elements 15 of at least one coil 7 on a movable stage 5 with a relative overlap R between them. Positioning may include visual and / or auditory guidance for manual positioning of the coil elements 15 to positions corresponding to the relative overlap R within a predefined critical range, based on the position of the detected markings. Additionally or alternatively, positioning may include automatic positioning of at least one coil 7 based on at least one software-controlled mechanism integrated into the coil 7.

[0125] In step S2, the relative overlap R of the coil element 15 is detected, for example, by measuring the noise correlation matrix (preferably by the overlap detection unit 21). In step S3, the determination unit 33 of the control unit 3 determines whether the detected relative overlap R is within a predefined critical range, for example, by comparing the measured noise correlation matrix with a predefined noise correlation matrix threshold and determining whether the detected relative overlap is within the predefined critical range based on the comparison result. When the detected relative overlap R is outside the predefined critical range, steps S1 to S3 (step S4) are repeated until the detected relative overlap R is within the predefined critical range, and then the image generation process begins when the movable stage 5 is in the final position for generating the image (step S5).

[0126] Method 100 may also include Figure 7 The steps not shown are: monitoring the relative overlap R of coil element 15 during the image generation process, and automatically repositioning coil element 15 during the image generation process when the monitored relative overlap R is detected to be outside a predefined critical range.

Claims

1. A system (1) for magnetic resonance imaging, comprising: Magnetic resonance imaging equipment (2), and The control unit (3) is configured to control the magnetic resonance imaging device (2). The magnetic resonance imaging device (2) includes: Magnetic resonance chamber (4). A movable worktable (5) is configured to be able to move into and out of the magnetic resonance chamber (4), and At least two coil elements (15) of at least one coil (7) are configured to be positioned adjacent to each other on the movable worktable (5) with relative overlap (R), and the at least one coil (7, 24) includes a housing (25) and an inner core (26), the inner core including the at least two coil elements (15) and configured to slide laterally in two dimensions within the housing (25) to achieve the relative overlap within a predefined critical range. The control unit (3) includes: A coil element detection unit (31) is configured to detect the at least two coil elements (15). An overlap detection unit (32) is configured to detect the relative overlap (R) of the at least two coil elements (15). Determining unit (33), configured to determine whether the detected relative overlap (R) is within the predefined critical range, and A position adjustment unit (34) is configured to adjust the relative position of the at least two coil elements (15) when the detected relative overlap (R) is outside the predefined critical range.

2. The system (1) according to claim 1, wherein, The at least two coil elements (15) are from different coils (7, 22, 24).

3. The system (1) according to claim 2, wherein, The at least one coil (7) has the form of a thin, flat, blanket-like pad.

4. The system (1) according to any one of claims 1-3, wherein, The coil element detection unit (31) includes at least one sensor configured to detect a mark on the at least one coil (7), wherein the sensor is selected from a 2D sensor group consisting of an optical video sensor, a capacitive sensor and an inductive sensor, or wherein the sensor is selected from a 3D video sensor group consisting of a radar sensor, a lidar sensor and an infrared sensor.

5. The system (1) according to any one of claims 1-3, wherein, The at least one coil (7) includes a sensing flexible area (20, 23).

6. The system (1) according to any one of claims 1-3, wherein, The magnetic resonance imaging device (2) further includes at least one coil holder configured to hold the at least one coil (7, 22, 24) in place.

7. The system (1) according to any one of claims 1-3, wherein, The at least one coil (24) also includes at least one actuator configured to move the inner core (26) at least between a first position without relative overlap (R) and a second position with said relative overlap (R).

8. The system (1) according to claim 7, wherein, The at least one actuator is coupled to the control unit (3), which is configured to control the actuator to move the inner core (26).

9. A method (100) for generating an image via magnetic resonance imaging, comprising: (a) Positioning at least two coil elements (15) of at least one coil (7) on a movable worktable (5) such that they have relative overlap (R) with each other, the at least one coil (7, 24) comprising a housing (25) and an inner core (26), the inner core comprising the at least two coil elements (15) and configured to slide laterally in two dimensions within the housing (25) to achieve the relative overlap within a predefined critical range; (b) Detect the relative overlap (R) of the at least two coil elements (15). (c) Determine whether the detected relative overlap (R) is within the predefined critical range. (d) When the detected relative overlap (R) is outside the predefined critical range, repeat steps (a) to (c); and (e) When the detected relative overlap (R) is within the predefined critical range and the movable stage (5) is in the final position for generating the image, the image generation process begins.

10. The method (100) according to claim 9, further comprising: (f) Monitoring the relative overlap (R) of the at least two coil elements (15) during the image generation process, and (g) When the monitored relative overlap (R) is detected to be outside the predefined critical range, the at least two coil elements (15) are repositioned during the image generation process.

11. The method (100) according to claim 9 or 10, wherein, Detecting the relative overlap (R) of the at least two coil elements (15) includes determining the noise correlation matrix.

12. The method (100) according to claim 9 or 10, wherein, Determining whether the detected relative overlap (R) is within a predefined critical range includes: comparing the measured noise correlation matrix with a predefined noise correlation matrix threshold, and determining whether the detected relative overlap (R) is within the predefined critical range based on the comparison result.

13. The method (100) according to claim 9 or 10, wherein, Positioning the at least two coil elements (15) further includes: detecting a mark provided on the at least one coil (7, 22, 24) or coil holder, thereby providing visual and / or auditory guidance for the manual positioning of the at least two coil elements (15) to a position corresponding to a relative overlap (R) within the predefined critical range based on the position of the detected mark.

14. The method (100) according to claim 9 or 10, wherein, The at least two coil elements (15) for positioning the at least one coil (7, 22, 24) further include: automatically positioning the at least one coil (7, 22, 24) based on at least one software-controlled mechanism integrated in the at least one coil (7, 22, 24).

15. A computer program product comprising a computer program configured to be stored on a control unit (3) of a system (1) according to any one of claims 1 to 8, and configured to cause the system (1) to perform the method (100) according to any one of claims 9 to 14 when executed by the control unit.

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