Array coil

Abstract

To simplify manufacturing and adjustment of an array coil.SOLUTION: An array coil according to the embodiment includes a first substrate and a second substrate. At least one coil element is formed on the first substrate. The second substrate is different from the first substrate, and is stacked on the first substrate. At least one coil element is formed on the second substrate. A first coil element formed on the first substrate and a second coil element formed on the second substrate intersect in a plane view from a stacking direction toward the first substrate from the second substrate stacked on the first substrate.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to array coils. To

Background Art

[0002] Conventionally, there has been a magnetic resonance imaging (MRI) apparatus that excites the nuclear spins of biological tissues placed in a strong static magnetic field with a high-frequency signal having its Larmor frequency, and reconstructs image data based on the magnetic resonance signal (MR signal) generated from the subject body accompanying this excitation. In an MRI apparatus, a high-frequency magnetic field generated by an RF coil that receives the supply of an RF signal amplified by an RF (Radio Frequency) amplifier is irradiated onto a subject placed in a static magnetic field.

[0003] For example, there is a technique for manufacturing an array coil (RF coil) including a plurality of coil elements by forming a coil pattern on a substrate. However, when forming a coil pattern in which coil elements intersect on the same plane, it has been necessary to manually solder a single wire serving as a jumper after forming the coil pattern on the substrate so that adjacent coil elements do not come into electrical contact with each other. Further, when adjacent coil elements are present, there has been a problem that adjustment work of the array coil, such as geometric decoupling, becomes complicated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] ​One of the problems that the embodiments disclosed herein and in the drawings aim to solve is to simplify the manufacturing and adjustment of array coils. However, the problems that the embodiments disclosed herein and in the drawings aim to solve are not limited to the above problem. Problems corresponding to each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0006] The array coil according to the embodiment comprises a first substrate and a second substrate. At least one coil element is formed on the first substrate. The second substrate is a substrate different from the first substrate and is laminated on the first substrate. At least one coil element is formed on the second substrate. The first coil element formed on the first substrate and the second coil element formed on the second substrate intersect in a plan view from the lamination direction from the second substrate toward the first substrate. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows an example of the configuration of a magnetic resonance imaging (MRI) device according to an embodiment. [Figure 2] Figure 2 shows an example of the configuration of a unit flexible substrate on which a coil element according to the embodiment is formed. [Figure 3] Figure 3 shows an example of the configuration of an array coil formed by stacking unit flexible substrates according to this embodiment. [Figure 4] Figure 4 shows another example of the configuration of an array coil formed by stacking unit flexible substrates according to the embodiment. [Figure 5] Figure 5 is a diagram illustrating geometric decoupling in an array coil according to an embodiment. [Figure 6]Figure 6 is a flowchart showing an example of the manufacturing process for an array coil according to the present invention. [Figure 7] Figure 7 shows an example of the configuration of an array coil formed by manually soldering on a flexible substrate, unlike the array coil according to the embodiment. [Modes for carrying out the invention]

[0008] The array coils and manufacturing methods according to each embodiment will be described below with reference to the drawings. In the following description, components having the same or substantially the same function as those previously described in the drawings will be denoted by the same reference numerals, and will be described again only when necessary. Furthermore, even when representing the same part, the dimensions and proportions may differ between drawings.

[0009] (First embodiment) Figure 1 shows an example of the configuration of a magnetic resonance imaging (MRI) apparatus 10 according to an embodiment. The MRI apparatus 10 is a device that reconstructs an image based on a magnetic resonance signal acquired by imaging in which a high-frequency magnetic field is irradiated onto a subject P placed in a static magnetic field. As shown in Figure 1, the MRI apparatus 10 comprises a magnet stand 111 and a patient table 121. The magnet stand 111 comprises a static magnetic field magnet 112, a gradient magnetic field coil unit 115 and an RF coil 116. Note that Figure 1 illustrates the internal configuration of the magnet stand 111 in a vertical cross-sectional view. Note that the MRI apparatus 10 does not include a subject P (e.g., a human body). Also, the configuration shown in Figure 1 is an example, and for example, some or all of the sequence control circuit 135 and console 141 may be integrated or separated as appropriate. For example, the MRI apparatus 10 is installed in an MR imaging room.

[0010] The gradient coil unit 115 includes a main coil 113 and a shield coil 114. The MRI apparatus 10 also includes a gradient power supply 131, a transmitting circuit 132, a receiving circuit 133, a patient control circuit 134, a sequence control circuit 135, and a console 141.

[0011] The static magnetic field magnet 112 has a generally cylindrical shape and generates a static magnetic field within a bore (the space inside the cylinder of the static magnetic field magnet 112) that includes the imaging area of ​​the subject P. The static magnetic field magnet 112 may be a superconducting magnet or a permanent magnet.

[0012] The gradient magnetic field coil unit 115 has a generally cylindrical shape and is held inside the static magnetic field magnet 112 by a support structure such as vibration-damping rubber. The gradient magnetic field coil unit 115 has a main coil 113 that applies (generates) gradient magnetic fields in mutually orthogonal directions by current supplied from the gradient magnetic field power supply 131, and a shield coil 114 that cancels the leakage magnetic field of the main coil 113.

[0013] The bed 121 is equipped with a top plate 122 on which the subject P is placed. Under the control of the bed control circuit 134, the top plate 122 is inserted into the cavity (imaging port) of the gradient coil unit 115 with the subject P placed on it. Under the control of the console 141, the bed control circuit 134 drives the bed 121 to move the top plate 122 in the longitudinal and vertical directions.

[0014] The RF (Radio Frequency) coil 116 is positioned inside the gradient magnetic field coil unit 115 and generates a high-frequency magnetic field by receiving RF pulses from the transmitting circuit 132. It also receives a magnetic resonance signal emitted from the subject P due to the influence of the high-frequency magnetic field and outputs the received magnetic resonance signal to the receiving circuit 133. The RF coil 116 may also be configured as a transmitting coil and a receiving coil.

[0015] The transmission circuit 132 supplies a high-frequency pulse modulated to the Larmor frequency (also referred to as the magnetic resonance frequency) to the RF coil 116 under the control of the sequence control circuit 135. In this embodiment, the high-frequency pulse modulated to the Larmor frequency (also referred to as the magnetic resonance frequency) may be described as an RF pulse or an RF signal. The magnetic resonance frequency is preset according to the magnetic rotation ratio corresponding to the atom to be magnetically resonated and the magnetic flux density of the static magnetic field. That is, the frequency of the RF signal varies according to the nuclide of the measurement target in the measurement based on the RF signal. When the magnetic flux density of the static magnetic field is 1.5 T, the magnetic resonance frequency is approximately 64 MHz. Also, when the magnetic flux density of the static magnetic field is 3 T, the magnetic resonance frequency is approximately 128 MHz. For example, the transmission circuit 132 includes an oscillation unit, a phase selection unit, a frequency conversion unit, an amplitude modulation unit, an RF amplifier, and the like.

[0016] The oscillation unit generates an RF pulse having a resonance frequency specific to the target atomic nucleus in the static magnetic field. The oscillation unit corresponds to a crystal oscillator using an oscillation circuit using a crystal oscillator and a frequency multiplier. That is, the crystal oscillator is an oscillator configured with an oscillation (system clock) obtained by multiplying the oscillation frequency of the crystal oscillator by an integer using a frequency multiplier as the source oscillation. Note that the oscillation circuit is not limited to using a crystal oscillator, and other oscillators may be used. Also, the oscillation unit may be provided in the processing circuit 142 or mounted on the console 141. At this time, the oscillation unit serves as the source oscillation for the overall control of the MRI apparatus 10.

[0017] The phase selection unit selects the phase of the RF pulse generated by the oscillation unit.

[0018] The frequency conversion unit converts the frequency of the RF pulse output from the phase selection unit.

[0019] The amplitude modulation unit modulates the amplitude of the RF pulse output from the frequency conversion unit according to, for example, the sinc function.

[0020] The RF amplifier amplifies the RF pulse having the resonance frequency output from the amplitude modulation unit and supplies it to the RF coil 116 via a duplexer (not shown). For example, the RF amplifier amplifies the RF pulse to 10-some kW to several 10 kW.

[0021] The reception circuit 133 detects the resonance signal output from the RF coil 116 and generates resonance data based on the detected resonance signal. Specifically, the reception circuit 133 generates resonance data by digitally converting the resonance signal received by the RF coil 116. Further, the reception circuit 133 transmits the generated resonance data to the sequence control circuit 135.

[0022] The sequence control circuit 135 executes a pulse sequence and images the subject P by driving the gradient magnetic field power supply 131, the transmission circuit 132, and the reception circuit 133 based on the sequence information transmitted from the console 141. Here, the sequence information is information defining the procedure for imaging. The sequence information defines, as a pulse sequence, the strength of the current supplied by the gradient magnetic field power supply 131 to the main coil 113, the timing of supplying the current, the strength of the RF pulse supplied by the transmission circuit 132 to the RF coil 116, the timing of applying the RF pulse, the timing at which the reception circuit 133 detects the resonance signal, and the like. For example, the sequence control circuit 135 is realized by a processor.

[0023] Note that the sequence information may include the nuclide to be measured and the frequency of the RF pulse (input signal) supplied to the RF coil 116.

[0024] Furthermore, when the sequence control circuit 135 drives the gradient magnetic field power supply 131, the transmission circuit 132, and the reception circuit 133 to image the subject P and receives the resonance data from the reception circuit 133, the received resonance data is transferred to the console 141.

[0025] Similarly, the transmitting circuit 132, receiving circuit 133, and bed control circuit 134, etc., are also composed of the above-mentioned processor and other electronic circuits.

[0026] Console 141 is a computer that controls the MRI device 10. Console 141 performs overall control of the MRI device 10, image generation, etc. Console 141 includes a processing circuit 142, a memory circuit 143, an input interface 144, a display 145, and a communication circuit 146.

[0027] The processing circuit 142 has a processor such as a CPU and memory such as ROM or RAM as hardware resources. The processing circuit 142 executes each function of the MRI device 10 by executing programs loaded into memory using the processor. The processing circuit 142 controls the entire MRI device 10, controlling imaging, image generation, image display, etc. For example, the processing circuit 142 receives input of imaging conditions (imaging parameters, etc.) on the GUI and generates sequence information according to the received imaging conditions. The processing circuit 142 also transmits the generated sequence information to the sequence control circuit 135. The processing circuit 142 also receives magnetic resonance data from the sequence control circuit 135 and stores the received magnetic resonance data in the storage circuit 143. The processing circuit 142 also reads k-space data from the storage circuit 143 and generates an image by applying reconstruction processing such as Fourier transform to the read k-space data. In other words, the processing circuit 142 reconstructs an image based on the magnetic resonance signal obtained by imaging in which a high-frequency magnetic field is irradiated onto a subject P placed in a static magnetic field.

[0028] The memory circuit 143 stores various types of information used by the processing circuit 142. Specifically, the memory circuit 143 stores magnetic resonance data received by the processing circuit 142, k-space data placed in k-space by the processing circuit 142, and image data generated by the processing circuit 142. The memory circuit 143 also stores various programs and setting information executed by the processing circuit 142. Specifically, the memory circuit 143 stores programs that assist in positioning the imaging range, programs related to signal processing of magnetic resonance data, and so on. For example, the memory circuit 143 can be implemented using semiconductor memory elements such as RAM, ROM, or flash memory, or a hard disk or optical disc.

[0029] The input interface 144 receives various input operations from the operator, converts the received input operations into electrical signals, and outputs them to the processing circuit 142. For example, the input interface 144 is a selection device such as a pointing device such as a mouse or trackball, or an input device such as a keyboard. An electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device located separately from the console 141 and outputs these electrical signals to the processing circuit 142 is also included as an example of the input interface 144.

[0030] The display 145, under the control of the processing circuit 142, displays a GUI (Graphical User Interface) for receiving input related to setting and adjusting imaging conditions, as well as images generated by the processing circuit 142. Various arbitrary displays can be used as the display 145 as appropriate. For example, a liquid crystal display (LCD), a cathode ray tube (CRT) display, an organic electroluminescent display (OLED), or a plasma display can be used as the display 145.

[0031] The display 145 may be installed in any location. For example, the display 145 may be installed in the shooting room or the control room. Alternatively, the display 145 may be installed on the magnetic mount 111. Furthermore, the display 145 may be a desktop type, or it may consist of a tablet terminal or the like that can communicate wirelessly with the main body of the console 141. In addition, one or more projectors may be used as the display 145.

[0032] The communication circuit 146 communicates with external devices such as the information processing device 30 via a network. The communication circuit 146 is, for example, a communication interface such as a network card, network adapter, or NIC (Network Interface Controller).

[0033] Figure 2 shows an example of the configuration of a unit flexible substrate 511 on which a coil element 513 according to the embodiment is formed.

[0034] As shown in Figure 2, multiple coil elements 513 are formed on the unit flexible substrate 511. In the unit flexible substrate 511, each coil element 513 is spaced apart from one another. In other words, in the unit flexible substrate 511, each coil element 513 does not intersect with an adjacent coil element 513. Here, the fact that adjacent coil elements 513 are spaced apart from one another, or that each coil element 513 does not intersect with an adjacent coil element 513, means that adjacent pairs of coil elements 513 are not electrically connected, i.e., they are not short-circuited.

[0035] In the example shown in Figure 3, each coil element 513 has a hexagonal shape. However, each coil element 513 may have other shapes, such as an elliptical shape, similar to the coil element 533 in Figure 4.

[0036] As an example, the unit flexible substrate 511 is formed from a flexible material such as polyimide or polycarbonate. However, the unit flexible substrate 511 may be formed from other materials.

[0037] Figure 3 shows an example of the configuration of an array coil 50 formed by stacking unit flexible substrates 511 according to the embodiment. The array coil 50 is an example of the RF coil 116 described above. Figure 3 illustrates a planar array coil 51 as an example of the array coil 50.

[0038] The planar array coil 51 has a plurality of unit flexible substrates 511. Figure 3 illustrates the plurality of unit flexible substrates 511 of the planar array coil 51, including a first unit flexible substrate 511a, a second unit flexible substrate 511b, and a third unit flexible substrate 511c. Figure 3 illustrates the case where the second unit flexible substrate 511b is laminated on the third unit flexible substrate 511c, and the first unit flexible substrate 511a is laminated on the second unit flexible substrate 511b. A plurality of coil elements 513a are formed on the first unit flexible substrate 511a. A plurality of coil elements 513b are formed on the second unit flexible substrate 511b. A plurality of coil elements 513c are formed on the third unit flexible substrate 511c.

[0039] Here, any unit flexible substrate 511 among the plurality of unit flexible substrates 511 (for example, the first unit flexible substrate 511a) is an example of the first substrate. Also, the coil elements formed on the first substrate among the plurality of unit flexible substrates 511 (for example, each of the plurality of coil elements 513a) are examples of the first coil elements. Also, other substrates among the plurality of unit flexible substrates 511 that are the same as the first substrate (for example, the second unit flexible substrate 511b or the third unit flexible substrate 511c) are examples of the second substrate. Also, the coil elements formed on the second substrate among the plurality of unit flexible substrates 511 (for example, each of the plurality of coil elements 513b or the plurality of coil elements 513c) are examples of the second coil elements.

[0040] The number of unit flexible substrates 511 in the planar array coil 51 can be appropriately determined based on the size of each unit flexible substrate 511 and the size of the planar array coil 51.

[0041] Specifically, the planar array coil 51 is formed by stacking a plurality of unit flexible substrates 511. In other words, the planar array coil 51 is divided into a plurality of unit flexible substrates 511 in the thickness direction. In the planar array coil 51, each unit flexible substrate 511 may be fixed to each other by, for example, an adhesive.

[0042] As described above, in a unit flexible substrate 511, each coil element 513 does not intersect with adjacent coil elements 513. On the other hand, as shown in Figure 3, each coil element 513 of the planar array coil 51 intersects in a direction perpendicular to the main surface of the planar array coil 51, that is, in a plan view from the stacking direction of the unit flexible substrates 511. In other words, the planar array coil 51 is formed by stacking each unit flexible substrate 511 such that the coil elements 513 formed on each different unit flexible substrate 511 intersect in a plan view.

[0043] In the example shown in Figure 3, the coil element 513a of the first unit flexible substrate 511a and the coil element 513b of the second unit flexible substrate 511b intersect in a plan view. Similarly, the coil element 513a of the first unit flexible substrate 511a and the coil element 513b of the second unit flexible substrate 511b intersect in a plan view. Similarly, the coil element 513b of the second unit flexible substrate 511b and the coil element 513c of the third unit flexible substrate 511c intersect in a plan view.

[0044] In addition, in the planar array coil 51, each unit flexible substrate 511 may be made of a material that does not have flexibility. In other words, each unit flexible substrate 511 of the planar array coil 51 does not have to be a flexible substrate.

[0045] Note that the array coil 50 formed by the unit flexible substrates 511 is not limited to a planar array coil 51. Figure 4 shows another example of the configuration of an array coil 50 formed by stacking unit flexible substrates 511 according to the embodiment. Figure 4 illustrates a volume array coil 53 as an example of an array coil 50.

[0046] The volume array coil 53 has a plurality of unit flexible substrates 531. The plurality of unit flexible substrates 531 have a configuration similar to the plurality of unit flexible substrates 511 in Figure 3.

[0047] Note that Figure 4 shows only one unit flexible substrate 531 as an example of the multiple unit flexible substrates 531 that the volume array coil 53 has. The number of multiple unit flexible substrates 531 in the volume array coil 53 can be appropriately determined based on the size of each unit flexible substrate 531 and the size of the volume array coil 53. Multiple coil elements 533 are formed on the unit flexible substrate 531.

[0048] Each coil element 533 has the same configuration as each coil element 513 in Figures 2 and 3. In the example shown in Figure 4, each coil element 533 has an elliptical shape. However, each coil element 533 may have other shapes, such as a hexagonal shape, similar to the coil element 513 in Figure 3.

[0049] Here, any unit flexible substrate 511 among the multiple unit flexible substrates 531 is an example of a first substrate. Also, each of the multiple coil elements 533 formed on the first substrate among the unit flexible substrates 531 is an example of a first coil element. Also, other substrates among the multiple unit flexible substrates 531 that are part of the first substrate are examples of a second substrate. Also, each of the multiple coil elements 533 formed on the second substrate among the multiple unit flexible substrates 531 is an example of a second coil element.

[0050] Specifically, the volume array coil 53 is formed by stacking and winding a plurality of unit flexible substrates 531 around an axis 535. In other words, the volume array coil 53 is divided into a plurality of unit flexible substrates 531 in the thickness direction, i.e., the radial direction of the axis 535. In the volume array coil 53, each unit flexible substrate 531 may be fixed to each other by, for example, an adhesive.

[0051] As described above, in a unit flexible substrate 531, each coil element 533 does not intersect with adjacent coil elements 533. On the other hand, in a volume array coil 53, each coil element 533 intersects in a plan view from the radial direction of the axis 535. In other words, a volume array coil 53 is formed by stacking unit flexible substrates 531 such that the coil elements 533 formed on each of the different unit flexible substrates 531 intersect in a plan view.

[0052] Figures 2 and 4 illustrate unit flexible substrates 511 and 531, each having four coil elements 513 and 533, but are not limited to these. The number of coil elements 513 and 533 formed on the unit flexible substrates 511 and 531 can be appropriately designed according to the high-frequency magnetic field required for the array coil 50, and may be one, two, three, or five or more.

[0053] The shape, size, and spacing of each coil element 513, 533, as well as the overall pattern of the coil elements 513, 533, are designed appropriately according to the high-frequency magnetic field required for the array coil 50, as will be described later.

[0054] Furthermore, in each unit flexible substrate 511, 531, the shape of each coil element 513, 533 is, for example, uniform, but may be different. Also, in each unit flexible substrate 511, 531, the size of each coil element 513, 533 is, for example, uniform, but may be different.

[0055] The size of each coil element 513, 533 can be appropriately designed depending on the location where the array coil 50 is installed. For example, the coil elements 513, 533 of the array coil 50 targeting the body surface of the subject P may be larger than the coil elements 513, 533 of the array coil 50 targeting deeper parts of the body surface of the subject P.

[0056] In addition, holes (not shown) are provided in the unit flexible substrates 511 and 531 at locations where they interfere with other components of the array coil 50, such as tuning circuits, matching circuits, capacitors, and other substrates.

[0057] Furthermore, it is acceptable for there to be areas in the array coil 50 where the unit flexible substrates 511 and 531 do not overlap. In other words, the unit flexible substrates 511 and 531 do not need to be stacked over the entire array coil 50.

[0058] In the array coil 50, the multiple unit flexible substrates 511 may be common, or at least one of the multiple unit flexible substrates 511 may be different from the other unit flexible substrates 511.

[0059] Here, "different unit flexible substrates 511, 531" may mean, for example, that the arrangement of coil elements 513, 533 in each unit flexible substrate 511, 531 is different. The arrangement of coil elements 513, 533 is defined by at least one of the number and position of the coil elements 513, 533.

[0060] For example, when the array coil 50 is applied to a body coil, the coil elements 513 and 533 are arranged on each unit flexible substrate 511 and 531 so that the distribution of coil elements 513 and 533 in the array coil 50 is uniform. For example, when the array coil 50 is applied to a head coil, the coil elements 513 and 533 are arranged on each unit flexible substrate 511 and 531 so that the coil elements 513 and 533 are densely packed on the head side of the array coil 50 where the subject P is located. In this way, by varying the arrangement of coil elements 513 and 533 on each unit flexible substrate 511 and 531, the resolution of the array coil 50 can be varied.

[0061] Note that "different unit flexible substrates 511, 531" may mean, for example, that the thickness of each unit flexible substrate 511, 531 is different.

[0062] Furthermore, in each unit flexible substrate 511, 531, the substrate thickness may be uniform, or there may be a distribution in the substrate thickness depending on the arrangement of, for example, the coil elements 513, 533.

[0063] Here, decoupling in the array coil 50 according to the embodiment will be described. Figure 5 is a diagram illustrating geometric decoupling in the array coil 50 according to the embodiment. The planar array coil 51 in Figure 5 illustrates a state in which a spacer 517 is inserted into the planar array coil 51 of Figure 3. Here, the spacer 517 is an example of an adjustment member.

[0064] For the sake of simplicity, this explanation will use the example of performing geometric decoupling on the planar array coil 51 shown in Figure 3, but the same principle applies to the volume array coil 53 shown in Figure 4.

[0065] As described above, the array coil 50 according to the embodiment can be formed by stacking a plurality of unit flexible substrates 511. Therefore, in the array coil 50 according to the embodiment, the coil element 513 can be moved for each unit flexible substrate 511. Accordingly, geometric decoupling of the array coil 50 according to the embodiment can be achieved by inserting spacers 517 between the unit flexible substrates 511 in the stacking direction. Geometric decoupling of the array coil 50 according to the embodiment can also be achieved by adjusting the position relative to other unit flexible substrates 511, i.e., the bonding position.

[0066] The spacer 517 is formed from a non-magnetic material that does not shield the magnetic field, such as glass, glass epoxy resin, or Teflon (registered trademark). The spacer 517 has, for example, a plate-like shape.

[0067] Specifically, the spacer 517 is positioned between adjacent unit flexible substrates 511 in the stacking direction, at a location where it intersects with the coil elements 513 to be adjusted in a plan view. This adjusts the distance (thickness) between the coil elements 513 formed on different unit flexible substrates 511, thereby allowing the amount of magnetic flux passing through the coil elements 513 to be adjusted to be adjusted.

[0068] In the example shown in Figure 5, the spacer 517a (spacer 517) is positioned where the coil element 513a of the first unit flexible substrate 511a and the coil element 513c of the third unit flexible substrate 511c intersect in a plan view. Here, the spacer 517a may be sandwiched between the first unit flexible substrate 511a and the second unit flexible substrate 511b, or between the second unit flexible substrate 511b and the third unit flexible substrate 511c. In other words, when decoupling coil elements 513 between unit flexible substrates 511 that are not adjacent in the stacking direction, the spacer 517 can be inserted between any pair of unit flexible substrates 511 on which the target coil element 513 is provided.

[0069] Furthermore, in the example shown in Figure 5, the spacer 517b (spacer 517) is positioned where the coil element 513a of the first unit flexible substrate 511a and the coil element 513b of the second unit flexible substrate 511b intersect in a plan view. The spacer 517b is, for example, sandwiched between the first unit flexible substrate 511a and the second unit flexible substrate 511b.

[0070] Furthermore, the spacer 517 is not limited to a plate shape; it may also be linear or have other shapes. Additionally, the spacer 517 may be inserted across the entire space between the unit flexible substrates 511. In other words, the spacer 517 may be used to change the distance between adjacent coil elements 513 in the stacking direction, or to change the distance between adjacent unit flexible substrates 511 themselves in the stacking direction.

[0071] Furthermore, the geometric decoupling of the array coil 51 according to this embodiment is not limited to the use of spacers 517, but may also be performed by using unit flexible substrates 511 of different thicknesses. Specifically, geometric decoupling may be achieved by replacing at least one of the unit flexible substrates 511 on which the coil elements 513 to be adjusted are formed with a unit flexible substrate 511 of a different thickness and in which the coil elements 513 are arranged in the same way. Note that the difference in thickness of the unit flexible substrates 511 may mean that the thickness is different throughout the entire unit flexible substrate 511, or that the thickness is locally different at the position where it intersects with the coil elements 513 of other unit flexible substrates 511 when stacked. Here, the unit flexible substrate 511 to be replaced can be described as an example of an adjustment member.

[0072] Furthermore, geometric decoupling can also be achieved by changing the line width of the coil element 513, such as by removing a portion of the coil element 513. In this case, geometric decoupling may also be achieved by replacing at least one of the unit flexible substrates 511 on which the coil element 513 to be adjusted is formed with a unit flexible substrate 511 in which the line width of the coil element 513 is different, i.e., the inductance is different, and the arrangement of the coil element 513 is the same.

[0073] As described above, since the array coil 51 according to this embodiment is formed by stacking a plurality of unit flexible substrates 511, geometric decoupling can be achieved by replacing some of the unit flexible substrates 511. Furthermore, since the line width can be adjusted for unit flexible substrates 511 that are not stacked, the adjustment work can be made easier.

[0074] Here, we will describe a method for manufacturing the array coil 50 (RF coil 116) according to the embodiment. Figure 6 is a flowchart showing an example of the manufacturing process for the array coil 50 according to the embodiment.

[0075] First, the arrangement of each coil element 513, 533 in the array coil 50 is determined (S101). The arrangement of each coil element 513, 533 can be appropriately designed, for example, according to the high-frequency magnetic field required for the array coil 50.

[0076] Next, the arrangement of each coil element 513, 533 in each of the multiple unit flexible substrates 511, 531 is determined (S102). Specifically, the arrangement of each coil element 513, 533 in the array coil 50 is divided, and the arrangement of each coil element 513, 533 in each unit flexible substrate 511, 531 is determined. At this time, among the coil elements 513, 533 in the array coil 50, the coil elements 513, 533 that would intersect if formed on the same plane are arranged in different unit flexible substrates 511, 531.

[0077] Then, individual coil elements 513, 533 are formed on the unit flexible substrates 511, 531, separated from each other (S103). Specifically, each coil element 513, 533 is printed on each unit flexible substrate 511, 531 according to the arrangement determined in S102.

[0078] Subsequently, the unit flexible substrates 511 and 531 on which the coil elements 513 and 533 are formed are stacked to form an array coil 50 (S104). In addition, decoupling is performed to adjust the distance between each coil element 513 and 533 by inserting spacers 571 between the unit flexible substrates 511 and 531, for example (S105).

[0079] As described above, the array coil 50 according to this embodiment has a plurality of stacked unit flexible substrates 511, 531. Furthermore, at least one coil element 513, 533 is formed on each of the plurality of unit flexible substrates 511, 531. Here, the first coil element formed on the first substrate and the second coil element formed on the second substrate intersect in a plan view from the stacking direction from the second substrate stacked on the first substrate toward the first substrate.

[0080] Figure 7 shows an example of the configuration of an array coil 60, which differs from the array coil 50 according to the embodiment, in that it is formed by manually soldering on a flexible substrate 615. For example, as shown in Figure 7, when forming a coil pattern in which coil elements 613 intersect on the same plane, it was necessary to manually solder jumper wires 617 after forming the coil pattern on the substrate so that adjacent coil elements 613 do not electrically contact each other. In the example shown in Figure 7, in order to form a coil element 613b that intersects with coil elements 613a and 613c on the same plane, it was necessary to connect each pattern constituting the coil element 613b, which was formed on the substrate at a distance from each other, by soldering a single wire 617b. Similarly, in order to form a coil element 613d that intersects with coil elements 613a and 613c on the same plane, it was necessary to connect each pattern constituting the coil element 613d, which was formed on the substrate at a distance from each other, by soldering a single wire 617d.

[0081] On the other hand, in the array coil 50 according to this embodiment, as described above, when formed on the same plane, the intersecting coil elements 513, 533 are formed on different unit flexible substrates 511, 531. With this configuration, it is possible to eliminate the need to manually solder jumper wires to the coil elements formed on the unit flexible substrates so that adjacent coil elements do not electrically contact each other.

[0082] In other words, the array coil 50 according to this embodiment can be formed by stacking a plurality of unit flexible substrates 511, 531, each having at least one coil element 513, 533 formed on it. Therefore, the array coil 50 according to this embodiment can be easily manufactured.

[0083] Furthermore, in the array coil 50 according to this embodiment, unlike the coil pattern shown in Figure 7, the multiple coil elements 513, 533 do not intersect each other on the unit flexible substrate 511, 531, that is, on the same plane. With this configuration, unlike the array coil 60 in Figure 7, adjacent coil elements 513, 533 do not electrically contact each other, so the work of manually soldering jumper wires 617 after forming the coil pattern on the substrate is eliminated. Therefore, the array coil 50 according to this embodiment can be manufactured simply. In addition, because adjacent coil elements are separated, adjustment work on the array coil, such as geometric decoupling, becomes easier, and the manufacturing of the array coil 50 can be made even simpler.

[0084] Furthermore, in the array coil 50 according to this embodiment, spacers 517 can be placed at the positions where intersecting coil elements 513, 533 intersect between a plurality of unit flexible substrates 511, 531, and when formed on the same plane, that is, at the positions where coil elements formed on different unit flexible substrates 511, 531 intersect in a plan view from the stacking direction. With this configuration, decoupling can be adjusted simply and without affecting the arrangement of the coil elements 513, 533.

[0085] Furthermore, since multiple unit flexible substrates 511, 531 can be stacked to form an array coil 50, flexible layout changes can also be achieved.

[0086] For example, the unit flexible substrates 511 and 531 to be superimposed can have the same arrangement of coil elements 513 and 533. On the other hand, the unit flexible substrates 511 and 531 to be superimposed can also have different arrangements of coil elements 513 and 533.

[0087] For example, the thicknesses of the stacked unit flexible substrates 511 and 531 can be the same or different.

[0088] For example, multiple planar array coils 51 are formed by stacking unit flexible substrates 511 and 531. The unit substrates used to form the planar array coils 51 can be flexible unit flexible substrates 511 and 531, or they can be non-flexible unit substrates. The unit substrates used to form the planar array coils 51 can also be a combination of flexible unit flexible substrates 511 and 531 and non-flexible unit substrates.

[0089] For example, a volume array coil 53 can be formed by winding flexible unit substrates 511 and 531 around a shaft 535.

[0090] Furthermore, when forming them on the same plane, even if the intersecting coil elements 513 and 533 are formed on different surfaces, the manual soldering of jumper wires to prevent adjacent coil elements from electrically contacting each other is eliminated.

[0091] However, when forming coil elements on both sides of a substrate, the coil elements cannot be divided into two or more layers. Therefore, when forming them on the same plane, it may not be possible to form all intersecting coil elements 513, 533 on different surfaces. On the other hand, in the array coil 50 according to this embodiment, three or more unit flexible substrates 511, 531 can be stacked. Therefore, when forming them on the same plane, all intersecting coil elements 513, 533 can be formed on different unit flexible substrates 511, 531, and all coil elements 513, 533 can be configured so that they do not intersect each other on the same plane.

[0092] Furthermore, when coil elements are formed on both sides of a substrate, the positions of the coil elements formed on one side and the coil elements formed on the other side are fixed in both the thickness direction and the horizontal direction. On the other hand, in the array coil 50 according to this embodiment, each unit flexible substrate 511, 531 can be stacked while adjusting it in both the thickness direction and the horizontal direction.

[0093] Furthermore, the array coil 50 according to the above embodiment can also be manufactured by stacking multiple unit flexible substrates 511, 531 in areas where the distribution of coil elements 513, 533 is uniform, while in areas where the distribution of coil elements 513, 533 is non-uniform, it can be manufactured by manually forming it as described with reference to the array coil 60 illustrated in Figure 7.

[0094] In the above description, the term "processor" refers to circuits such as CPUs, GPUs, ASICs, and Programmable Logic Devices (PLDs). PLDs include Simple Programmable Logic Devices (SPLDs), Complex Programmable Logic Devices (CPLDs), and Field Programmable Gate Arrays (FPGAs). A processor functions by reading and executing programs stored in memory circuits. The memory circuit storing the program is a computer-readable, non-temporary recording medium. Alternatively, instead of storing the program in a memory circuit, the processor may be configured to directly incorporate the program into its circuitry. In this case, the processor functions by reading and executing the program incorporated into the circuitry. Furthermore, instead of executing the program, the processor may implement the function corresponding to the program through a combination of logic circuits. In this embodiment, each processor is not limited to being configured as a single circuit; multiple independent circuits may be combined to form a single processor, and its functions may be implemented from there. Additionally, multiple components shown in Figure 1 may be integrated into a single processor to implement its functions.

[0095] According to at least one embodiment described above, the manufacturing and adjustment of array coils can be simplified.

[0096] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0097] With respect to the above embodiments, the following additional notes are disclosed as aspects of the invention and selective features.

[0098] (Note 1) A first substrate on which at least one coil element is formed, A substrate different from the first substrate on which at least one coil element is formed, and a second substrate laminated on the first substrate. Equipped with, The first coil element formed on the first substrate and the second coil element formed on the second substrate intersect in a plan view from the stacking direction from the second substrate toward the first substrate, which is stacked on the first substrate. Array coil.

[0099] (Note 2) Multiple coil elements may be formed on at least one of the first substrate and the second substrate. In the substrate on which the plurality of coil elements are formed, the plurality of coil elements do not have to intersect with each other.

[0100] (Note 3) The array coil may further include an adjustment member positioned between the first substrate and the second substrate, where the first coil element and the second coil element intersect in the plan view.

[0101] (Note 4) The first substrate and the second substrate may have the same arrangement of coil elements.

[0102] (Note 5) The first substrate and the second substrate may have different arrangements of coil elements.

[0103] (Note 6) The first substrate and the second substrate may have different thicknesses.

[0104] (Note 7) The array coil may comprise a plurality of substrates, each having a plurality of coil elements formed on it, including the first substrate and the second substrate. Each of the plurality of substrates may be laminated on at least one other substrate among the plurality of substrates.

[0105] (Note 8) The first substrate and the second substrate may each be flexible substrates having flexibility.

[0106] (Note 9) The aforementioned array coil may be a planar array coil.

[0107] (Note 10) The array coil may be a volume array coil.

[0108] (Note 11) Forming at least one coil element on the first substrate, At least one coil element is formed on a second substrate different from the first substrate, In a plan view from the stacking direction toward the first substrate, the second substrate is stacked on the first substrate such that, in a plan view from the stacking direction toward the first substrate, the first coil element formed on the first substrate and the second coil element formed on the second substrate intersect. A method for manufacturing an array coil containing [the specified component].

[0109] (Note 12) The manufacturing method may include forming a plurality of coil elements on at least one of the first substrate and the second substrate. The manufacturing method may include ensuring that the plurality of coil elements on the substrate on which the plurality of coil elements are formed do not intersect with each other.

[0110] (Note 13) The manufacturing method may further include arranging an adjustment member between the first substrate and the second substrate, at a position where the first coil element and the second coil element intersect in the plan view.

[0111] (Note 14) The manufacturing method may include arranging the same coil element on the first substrate and the second substrate.

[0112] (Note 15) The manufacturing method may include arranging different coil elements on the first substrate and the second substrate.

[0113] (Note 16) The manufacturing method may include making the first substrate and the second substrate of different thicknesses.

[0114] (Note 17) The manufacturing method may include forming a plurality of coil elements on each of a plurality of substrates, including the first substrate and the second substrate. The manufacturing method may include stacking each of the plurality of substrates on at least one other substrate among the plurality of substrates.

[0115] (Note 18) The manufacturing method may include making the first substrate and the second substrate flexible substrates that have flexibility.

[0116] (Note 19) The manufacturing method may include making the array coil a planar array coil.

[0117] (Note 20) The manufacturing method may include making the array coil a volume array coil. [Explanation of symbols]

[0118] 10 MRI machine 132 Transmitter Circuit 133 Receiving Circuit 135 Sequence control circuit 141 Console 142 Processing Circuit 50 Array Coils 51 Planar Array Coils 511 Unit Flexible Substrate (First Substrate, Second Substrate) 513 Coil element (first coil element, second coil element) 517 Spacer (adjustment component) 53 Volume Array Coil 531 units of flexible substrate (first substrate, second substrate) 533 Coil element (first coil element, second coil element) 535 axis

Claims

1. A first substrate having at least one coil element on one main surface that does not intersect with other coil elements on the same substrate, A substrate having at least one coil element on one main surface which does not intersect with other coil elements on the same substrate, and a second substrate laminated on the first substrate, The device comprises an adjustment member positioned between the first substrate and the second substrate, In a plan view along a direction perpendicular to one main surface of the first substrate, the region enclosed by the first coil element of the first substrate and the region enclosed by the second coil element of the second substrate overlap in at least a portion of the same area. The adjustment member is positioned at a location where the first coil element and the second coil element intersect in a plan view along the direction. The first substrate is a flexible substrate having flexibility, The first substrate and the second substrate differ in substrate thickness in the aforementioned direction. The distance in the aforementioned direction between the coil element of the first substrate and the coil element of the second substrate is determined by the substrate thickness of the first substrate and the length of the adjustment member in the aforementioned direction at the intersection where the adjustment member is positioned, and by the substrate thickness of the first substrate at other positions at the intersection. The distance between the first substrate and the second substrate in the aforementioned direction differs between the intersection point and other positions at the intersection point. Array coil.

2. The substrate thickness of the first substrate or the second substrate has a distribution corresponding to the arrangement of coil elements provided on the substrate. The array coil according to claim 1.

3. The first substrate and the second substrate overlap in the first region and do not overlap in the second region when viewed in a plan view along the aforementioned direction. The array coil according to claim 1 or claim 2.

4. The first region is a region in which a plurality of coil elements are uniformly distributed in a plan view along the aforementioned direction. The second region is a region in which a plurality of coil elements are unevenly distributed in a plan view along the aforementioned direction. The plurality of coil elements in the first region are such that a portion is provided on the first substrate and another portion is provided on the second substrate, and each coil element does not intersect with other coil elements on the same substrate in a plan view along the aforementioned direction. The plurality of coil elements in the second region are all provided on either the first substrate or the second substrate, and include coil elements that intersect with other adjacent coil elements on the same substrate in a plan view along the direction and do not electrically contact each other. The array coil according to claim 3.

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