Receiving coil device, and magnetic resonance imaging device

Abstract

To provide a receiving coil device and a magnetic resonance imaging device that can automatically wrap and unwrap a receiving coil around an examination part a subject.SOLUTION: A receiving coil device is provided in a magnetic resonance imaging device, and receives a nuclear magnetic resonance signal. The receiving coil device comprises: a receiving coil 203 for receiving the nuclear magnetic resonance signal; and a flexible band 210 housing the receiving coil 203, partially fixed to a top plate 132 of a bed, whose shape is changed by supply and / or discharge of fluid, wrapping the receiving coil 203 around an examination part of a subject 102 on the bed, or unwrapping the receiving coil 203.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a receive coil device and a magnetic resonance imaging apparatus, and more particularly to a technique for automatically setting a receive coil at an examination site of a subject. [Background technology]

[0002] In an MRI examination using a magnetic resonance imaging (MRI) device, radio frequency (RF) waves at a resonant frequency specific to an element are irradiated onto the subject's examination area, the generated nuclear magnetic resonance (NMR) signal is received by a receiving coil (also called an RF coil), and an image (MRI image) is generated from the received NMR signal.

[0003] Before starting an MRI scan, technicians must manually set the receiving coil at the subject's examination site, paying attention to the patient's condition, positioning, the presence of metal or other contraindications for MRI, and the presence of cable loops that could lead to burns.

[0004] Setting the receiving coil manually in this manner is time-consuming and is one of the factors that extends the examination time, so there has been a demand for simplifying the setting of the receiving coil and reducing the burden.

[0005] US Pat. No. 5,399,433 describes an assembly for attaching a local coil (receiving coil) to a patient for magnetic resonance diagnosis.

[0006] The assembly described in Patent Document 1 comprises a receiving coil (local coil) configured to receive NMR signals, and a support device configured to house the local coil and attach the local coil to a patient.

[0007] The support device is configured as a gas-filled cushion and has a device for varying the gas pressure, whereby the shape of the cushion changes in relation to the gas pressure, i.e., the support device presses the local antenna against the patient in response to the change in shape of the cushion due to the change in gas pressure.

[0008] Specifically, the cushion is composed of a base plate formed as an elastic plastic plate, a non-breathable hard foam having cutouts adhesively bonded to the base plate, and a breathable soft foam filled in the cutouts, and the unit formed of the base plate, the hard foam, and the soft foam is pressed into a non-breathable cover and vacuum-tightly bonded.

[0009] The air inside the cover is then expelled, causing the breathable soft foam to shrink, and the shape of the cushion changes depending on the relationship between the contracted soft foam and the non-contracting non-breathable hard foam, causing the local coil to deform to fit the patient's body. The degree of deformation or deformation pressure is adjusted by the degree of vacuum generated when the air is expelled.

[0010] Patent Document 2 also proposes a device for fixing a high-frequency coil to a subject. This high-frequency coil has a flexible substrate and an exterior part provided so as to cover the substrate, and has foam beads filled to the extent that air is present in the gap between the flexible substrate and the exterior part. After the high-frequency coil is attached to the subject by an operator, the air in the exterior part is sucked in, and the coil is fixed in a shape that conforms to the subject. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2009-11837 A [Patent Document 2] JP 2011-30828 A Summary of the Invention [Problem to be solved by the invention]

[0012] According to the assembly described in Patent Document 1, the air inside the cover of the support device is evacuated (sucked) and the shape of the cushion is changed depending on the degree of vacuum inside the cover, allowing the local coil to be deformed (wrapped) to fit the patient's body; however, the wrapping cannot be undone automatically and it is necessary to open a valve and wait until the degree of vacuum inside the cover becomes equal to the ambient air pressure.

[0013] In addition, the assembly is not fixed to the bed, and the technician must position the assembly according to the part of the subject to be examined, which is time-consuming.

[0014] In addition, the device described in Patent Document 2 can fix (fix in close contact with) the high-frequency coil to the surface shape of the subject by sucking in the air from the exterior of the high-frequency coil, but the operator must place the high-frequency coil on the subject in advance (before the air from the exterior is sucked in), which is time-consuming.

[0015] The present invention has been made in consideration of the above circumstances, and has an object to provide a receive coil device and a magnetic resonance imaging device that can automatically wind and unwind a receive coil around an examination site of a subject. [Means for solving the problem]

[0016] The invention of a first aspect is a receive coil device provided in a magnetic resonance imaging apparatus for receiving nuclear magnetic resonance signals, the receive coil device comprising: a receive coil for receiving nuclear magnetic resonance signals; and a flexible band that houses the receive coil and has a portion fixed to a bed, the flexible band changing shape by the supply and / or discharge of fluid, and winding the receive coil around an examination site of a subject placed on the bed or unwinding the receive coil.

[0017] According to the first aspect of the present invention, an operator need only position the subject's examination area relative to a flexible band fixed to the bed before an MRI examination, and then the receiving coil can be automatically wrapped around the examination area. Furthermore, after the MRI examination is completed, the receiving coil can be automatically undone.

[0018] In the receiving coil device of the second aspect of the present invention, in the first aspect, the flexible band is configured by joining a first layer that houses the receiving coil and a second layer that has a bag-shaped structure and bends or stretches due to fluid supplied to or discharged from the bag-shaped structure, and when fluid is supplied to the bag-shaped structure, it is preferable that the flexible band bends to wrap the receiving coil around the examination site, and when fluid is discharged from the bag-shaped structure, the flexible band unwraps the receiving coil.

[0019] In the receive coil device according to a third aspect of the present invention, in the second aspect, it is preferable that the first layer has a first bag-shaped structure portion that houses the receive coil.

[0020] In the receiver coil device according to the fourth aspect of the present invention, in the second or third aspect, it is preferable that the first layer is disposed on the inner circumferential side of the curved flexible band, whereby the receiver coil can be wound closer to the examination site of the subject.

[0021] A receiving coil device according to a fifth aspect of the present invention is, in the first aspect, a flexible band configured by joining a first layer that houses a receiving coil, a second layer having a second bag-shaped structure and that stretches due to fluid supplied to the second bag-shaped structure, and a third layer having a third bag-shaped structure and that curves due to fluid supplied to the third bag-shaped structure, and it is preferable that when fluid is discharged from the third bag-shaped structure and fluid is supplied to the second bag-shaped structure, the receiving coil stretches, making it possible to release the winding around at least the examination site, and when the fluid is supplied to the third bag-shaped structure, the receiving coil curves and wraps around the examination site.

[0022] According to a sixth aspect of the present invention, in the fifth aspect, it is preferable that the flexible band is joined in the order of the first layer, the second layer and the third layer from the innermost side of the flexible band, or that the flexible band is joined in the order of the second layer, the first layer and the third layer from the innermost side of the flexible band.

[0023] In the receiving coil device according to a seventh aspect of the present invention, in the fifth or sixth aspect, it is preferable that the first layer is arranged on the innermost side of the curved flexible band, and the second and third layers are arranged on the outer side of the first layer. This makes it possible to wind the receiving coil closer to the examination site of the subject.

[0024] A receiver coil device according to an eighth aspect of the present invention is based on any one of the fifth to seventh aspects, and it is preferable that the first layer has a first bag-shaped structure portion that houses the receiver coil.

[0025] A ninth aspect of the present invention is a receiving coil device in any one of the second to fourth aspects, which comprises a fluid pressure circuit having a fluid supply source for supplying and / or discharging fluid, a tube arranged between the fluid pressure source and a bag-shaped structure, and a solenoid valve arranged in the tube for switching the direction of fluid flowing through the tube, and a control unit for controlling the fluid pressure source and the solenoid valve, and it is preferable that, upon receiving an instruction to wind the receiving coil, the control unit controls the fluid pressure source and the solenoid valve to supply fluid from the fluid pressure source to the bag-shaped structure via the solenoid valve and the tube, thereby winding the receiving coil around the examination site, and, upon receiving an instruction to unwind the receiving coil, discharges fluid from the bag-shaped structure via the tube and the solenoid valve to unwind the receiving coil from the examination site.

[0026] A receiving coil device according to a tenth aspect of the present invention, in any one of the fifth to eighth aspects, preferably includes a fluid pressure circuit having a fluid pressure source for supplying and / or discharging a fluid, a first tube and a second tube disposed between the fluid pressure source and the second bag-like structure and a solenoid valve disposed in the first tube and the second tube for switching the direction of the fluid flowing through the first tube and the second tube, and a control unit for controlling the fluid pressure source and the solenoid valve, wherein the control unit, upon receiving an instruction to wind the receiving coil, controls the fluid pressure source and the solenoid valve to discharge the fluid from the second bag-like structure via the first tube and the solenoid valve, and supplies fluid from the fluid pressure source to the third bag-like structure via the solenoid valve and the second tube to wind the receiving coil around the examination site, and, upon receiving an instruction to unwind the receiving coil, preferably controls the fluid to discharge the fluid from the third bag-like structure via the second tube and the solenoid valve, and supplies fluid from the fluid pressure source to the second bag-like structure via the solenoid valve and the first tube to unwind the receiving coil from the examination site.

[0027] In the receive coil device according to an eleventh aspect of the present invention, in the ninth or tenth aspect, it is preferable that the control unit receives an instruction to lift the bed or a first timing in the control of lifting the bed as an instruction to wind the receive coil. With this, even if the operator does not give an instruction to wind the receive coil, the receive coil can be automatically wound around the examination site at a desired timing.

[0028] In the receive coil device according to the twelfth aspect of the present invention, in the ninth or tenth aspect, it is preferable that the control unit receives, as an instruction to unwind the receive coil, an instruction to withdraw the bed from the gantry of the magnetic resonance imaging apparatus or a second timing in the control of drawing out the bed. With this, even if the operator does not issue an instruction to unwind the receive coil, it is possible to automatically unwind the receive coil from the examination site at a desired timing.

[0029] A thirteenth aspect of the invention is a magnetic resonance imaging apparatus including the receive coil device according to any one of the first to twelfth aspects. Effect of the Invention

[0030] According to the present invention, a receiving coil can be automatically wound around the examination area of ​​a subject lying on a bed, and the receiving coil can be automatically undone, thereby simplifying the setting of the receiving coil on the operator and reducing the burden on the operator. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view showing the appearance of a magnetic resonance imaging apparatus (MRI apparatus) equipped with a receive coil device according to the present invention. [Diagram 2] FIG. 2 is a diagram showing a schematic internal configuration of the MRI apparatus shown in FIG. [Diagram 3] FIG. 3 is a diagram showing a first embodiment of a receive coil device according to the present invention. [Figure 4] FIG. 4 is a diagram showing a main part of a second embodiment of a receive coil device according to the present invention. [Diagram 5] FIG. 5 is a development view in which the respective bag-shaped structural parts constituting the flexible band shown in FIG. 4 are separated and arranged. [Figure 6] FIG. 6 is a transition diagram showing an outline of the operation of the flexible band housing the receiving coil and the operation of the bed. [Figure 7] FIG. 7 is a diagram showing an example of a drive and control unit of the flexible band shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a receive coil device and a magnetic resonance imaging apparatus according to the present invention will be described with reference to the accompanying drawings.

[0033] [External appearance of MRI device] FIG. 1 is a perspective view showing the appearance of a magnetic resonance imaging apparatus (MRI apparatus) equipped with a receive coil device according to the present invention.

[0034] The MRI apparatus 100 shown in FIG. 1 includes a gantry 110, a bed 130 having a top plate 132 arranged at the front side of a bore 120, which is a cylindrical imaging space provided in the gantry 110, and a receive coil device 200, a portion of which is fixed to the bed 130.

[0035] [Internal structure of MRI device] FIG. 2 is a diagram showing a schematic internal configuration of the MRI apparatus shown in FIG.

[0036] As shown in FIG. 2, the MRI apparatus 100 includes a static magnetic field generating magnet 104 that generates a uniform static magnetic field in an imaging space in which the subject 102 is placed, a gradient magnetic field coil 106 that generates a gradient magnetic field in the imaging space, an RF (Radio Frequency) coil (transmitting coil) 108 that generates a high-frequency magnetic field that generates a nuclear magnetic resonance signal (NMR signal) in the nuclei of atoms that constitute the tissue of the subject 102, and a receiving coil device 200 that includes a receiving coil that detects the NMR signal generated from the subject 102.

[0037] The receive coil device 200 has a portion fixed to a top plate 132 (FIG. 1) of the bed 130. The subject 102 is usually placed in the imaging space while lying on the top plate 132 of the bed 130. The receive coil device 200 will be described in detail later.

[0038] The sequencer 118 sends commands to the high frequency magnetic field generator 112 and the gradient magnetic field power supply 116 according to an imaging sequence (pulse sequence), causing them to generate a high frequency magnetic field and a gradient magnetic field, respectively. The generated high frequency magnetic field is applied to the subject 102 as a pulsed high frequency magnetic field (RF pulse) through the transmission coil 108. The NMR signal generated from the subject 102 is received by the receiving coil device 200 and detected by the receiver 114.

[0039] The gradient magnetic field coil 106 is composed of gradient magnetic field coils in three directions, X, Y, and Z, and generates gradient magnetic fields in response to signals from a gradient magnetic field power supply 116 .

[0040] The nuclear magnetic resonance frequency (detection reference frequency f0) used as the detection reference in the receiver 114 is set by the sequencer 118. The sequencer 118 controls each part so that it operates at pre-programmed timing and intensity. Among the programs, those that particularly describe the timing and intensity of the RF pulse, gradient magnetic field, and signal reception are called a pulse sequence.

[0041] There are various known pulse sequences depending on the purpose, but the details are omitted here.

[0042] The control unit 140 controls the operation of the MRI apparatus 100 via the sequencer 118, receives the signal detected by the receiver 114, and performs various signal processing such as image reconstruction. The receiver 114 performs quadrature phase detection of the echo signal, which is an analog wave, using a set detection reference frequency f0, converts it into raw data, and transmits it to the control unit 140. This raw data is also called an echo signal or measurement data.

[0043] The control unit 140 can be configured using a computer. The computer applied to the control unit 140 may be a personal computer or a workstation.

[0044] The control unit 140 receives various instruction inputs from the operation unit 150, and controls each part of the MRI apparatus 100 in an integrated manner. It also performs processes such as converting the echo signals in the spatial frequency domain received via the sequencer 118 into images in real space by inverse Fourier transform, thereby generating an MRI image.

[0045] The operation unit 150 includes a mouse, a keyboard, and the like, and functions as a part of a GUI (Graphical User Interface) that receives input from an operator using a display operation window on a display (not shown).

[0046] That is, the operation unit 150 and the display function as a GUI for the operator to start and stop (pause) the MRI apparatus 100, select a pulse sequence, and input imaging conditions and processing conditions, etc. Also, the operation unit 150 in this example functions as an operation unit (operation buttons) used when the operator lifts the bed 130 (top board 132) at the start of an examination, or when the subject pulls out the bed 130 (top board 132) from the gantry 110 at the end of an examination.

[0047] [Receiving coil device] First Embodiment FIG. 3 is a diagram showing a first embodiment of a receive coil device according to the present invention.

[0048] The receive coil device 200 shown in FIG. 3 is composed of a receive coil 203, a flexible band 210, a fluid pressure circuit 220, a control unit 230, and an operation unit 232.

[0049] The receiving coil 203 is formed of, for example, a flexible wiring pattern or the like, and can be freely wound around an examination site of the subject 102. A nuclear magnetic resonance signal (NMR signal) received by the receiving coil 203 during an examination is transmitted to the receiver 114 via an amplifier 205.

[0050] A part of the flexible band 210, that is, a fixed part 210A, is fixed to the bed 130 (top board 132).

[0051] This flexible band 210 is configured by joining a first layer having a first bag-like structure 202 that houses a receiving coil 203, and a second layer having a bag-like structure 204 that curves or expands due to a fluid supplied to or discharged from the bag-like structure 204. Note that the fluid supplied to or discharged from the bag-like structure 204 is air in this example, but the present invention is not limited to this.

[0052] A plurality of pleats are formed on the surface of bag-shaped structure 204 opposite to the first layer (first bag-shaped structure 202), and when compressed air is supplied to bag-shaped structure 204 and the inside of bag-shaped structure 204 is pressurized, the pleats spread. As a result, bag-shaped structure 204 deforms so as to curve flexible band 210 with the first layer (receiving coil 203) on the inside due to the area difference between the inner surface on the first layer side and the outer surface having the pleats.

[0053] That is, the flexible band 210 moves (rises) at both ends in the direction of arrow A in FIG.

[0054] On the other hand, when air is supplied to the bag-like structure 204 and the flexible band 210 is wrapped around the subject 102, if the air is discharged from the bag-like structure 204, the wrapping force by the bag-like structure 204 disappears.

[0055] As a result, flexible band 210 moves (descends) in the direction of arrow B, and extends so as to follow top board 132. That is, as shown in Fig. 3, flexible band 210 extends, and reception coil 203 is released from its winding.

[0056] In this manner, the flexible band 210 changes shape by supplying and / or discharging compressed air to the bag-like structure 204, thereby winding or unwinding the receive coil around the examination site of the subject 102 on the bed 130.

[0057] The fluid pressure circuit 220 is made up of a pressure increasing / decreasing pump 221 , a tube 222 , a solenoid valve 224 , a pressure sensor 226 , and a relief valve 228 .

[0058] The pressurizing and depressurizing pump 221 functions as a fluid pressure source that supplies and / or discharges fluid, and is a pressure source for supplying air to the bag-like structure 204 of the flexible band 210, bending the flexible band 210, or discharging (sucking) air from the bag-like structure 204, and stretching the flexible band 210.

[0059] The tube 222 is a pipe that connects the air supply / exhaust port of the bag-shaped structure 204 of the flexible band 210 to the pressurizing / depressurizing pump 221 .

[0060] The solenoid valve 224 is a two-way, two-position solenoid valve disposed in the tube 222. When the solenoid 224A is excited, the solenoid valve 224 is turned on, enabling switching between supplying and discharging air to and from the bag-like structure 204 via the tube 222, and when the solenoid 224A is demagnetized, the solenoid valve 224 is turned off, blocking the flow of air.

[0061] The pressure sensor 226 detects the pressure inside the bag-like structure 204 and outputs a pressure signal indicative of the detected pressure to the control unit 230 .

[0062] The relief valve 228 functions as a safety valve that opens and discharges air when the pressure inside the bag-like structure 204 becomes abnormal.

[0063] The control unit 230 is a part that controls the pressurizing and depressurizing pump 221 and the solenoid valve 224 in response to an instruction from the operation unit 232 to wind the receiving coil 203 or an instruction to unwind the receiving coil 203, and wraps the receiving coil 203 around the examination area of ​​the subject 102 or unwinds the receiving coil 203 from the examination area.

[0064] That is, when the control unit 230 receives an instruction to wind the receiving coil 203 from the operation unit 232, it turns on the solenoid valve 224, and then drives and controls the pressurizing and depressurizing pump 221 so that compressed air is discharged from the pressurizing and depressurizing pump 221. After that, when the control unit 230 detects based on a detection signal from the pressure sensor 226 that the pressure inside the bag-shaped structure 204 of the flexible band 210 has reached a preset reference pressure, it stops the pressurizing and depressurizing pump 221, and then turns off the solenoid valve 224.

[0065] This allows the control unit 230 to automatically wrap the receiving coil 203 together with the flexible band 210 around the examination site of the subject 102.

[0066] The reference pressure is preferably set so that the flexible band 210 (receiving coil 203) curves and wraps around the examination site of the subject 102, and is tight enough not to obstruct blood flow at the examination site.

[0067] On the other hand, when the control unit 230 receives an instruction to unwind the receiving coil 203 from the operation unit 232, it turns on the solenoid valve 224, and then drives and controls the pressurizing and depressurizing pump 221 so as to exhaust (suck) the air inside the bag-like structure 204. After that, when the control unit 230 detects based on the detection signal of the pressure sensor 226 that the pressure inside the bag-like structure 204 of the flexible band 210 has reached or below atmospheric pressure, it stops the pressurizing and depressurizing pump 221, and then turns off the solenoid valve 224.

[0068] This allows the control unit 230 to extend the receiving coil 203 together with the flexible band 210, and automatically release the receiving coil 203 from being wrapped around the examination region.

[0069] In this example, the signal cable of the receiving coil 203 and the tube 222 connected to the bag-shaped structure 204 extend below the top plate 132 via the fixing portion 210A of the flexible band 210, but it goes without saying that the signal cable of the receiving coil 203 and the tube 222 are wired and piped so as not to hinder the movement of the top plate 132 when the bed 130 (top plate 132) is raised and lowered, and when the top plate 132 is inserted and removed from the bore 120.

[0070] Furthermore, the signal cable of the receiving coil 203 and the tube 222 from the flexible band 210 are not limited to being led into the bed 130 via the fixed part 210A of the flexible band 210, but for example, the signal cable of the receiving coil 203 and a part of the tube 222 may be arranged along the tabletop 132 or the bed 130.

[0071] <Second embodiment> FIG. 4 is a diagram showing a main part of a second embodiment of a receive coil device according to the present invention, and shows a state in which a flexible band constituting the receive coil device is wrapped around a subject.

[0072] The flexible band 240 of the receiving coil device shown in Figure 4 is constructed by joining a first layer having a first bag-shaped structure 242 that houses the receiving coil 203, a second layer having a second bag-shaped structure 244 and that expands due to fluid supplied to the second bag-shaped structure 244, and a third layer having a third bag-shaped structure 246 and that bends due to fluid supplied to the third bag-shaped structure 246.

[0073] FIG. 5 is a development view in which the respective bag-shaped structural parts constituting the flexible band shown in FIG. 4 are separated and arranged.

[0074] As shown in FIG. 5, the first bag-shaped structure 242 on the innermost side of the flexible band 240 is the shortest in length, followed by the second bag-shaped structure 244 and the third bag-shaped structure 246 in that order.

[0075] In addition, the first bag-shaped structure 242 and the second bag-shaped structure 244 have their respective ends joined at end points 243A and 243B, and the second bag-shaped structure 244 and the third bag-shaped structure 246 have their respective ends joined at end points 245A and 245B.

[0076] Therefore, when fluid (air) is discharged from the second bag-like structure 244 and fluid (air) is supplied to the third bag-like structure 246, the inner length of the third bag-like structure 246 is constrained to the length of the second bag-like structure 244 by the end points 245A, 245B joined to the second bag-like structure 244, while the outer end points 247A, 247B are not constrained, and so the third bag-like structure 246 extends to its original length.

[0077] As a result, a difference in length occurs between the inside and outside of the third bag-shaped structure 246, and the third bag-shaped structure 246 deforms and curves inward, wrapping the flexible band 210 (receiving coil 203) around the examination area of ​​the subject 102 as shown in Figure 4.

[0078] On the other hand, when air is discharged from the third bag-shaped structure 246 and air is supplied to the second bag-shaped structure 244, the inner length of the second bag-shaped structure 244 is constrained to the length of the first bag-shaped structure 242 by the end points 243A, 243B joined to the first bag-shaped structure 242, while the outer end points 245A, 245B are not constrained, and so the second bag-shaped structure 244 extends to its original length.

[0079] As a result, the second sac-like structure 244 is stretched, and the flexible band 240 is stretched as a whole, but in this example, the inner length of the second sac-like structure 244 is constrained to the length of the first sac-like structure 242 by the end points 243A and 243B joined to the first sac-like structure 242, so that a difference occurs between the inner and outer lengths of the second sac-like structure 244, and the second sac-like structure 244 is deformed to curve inward. However, it is preferable to design the difference in length between the first sac-like structure 242 and the second sac-like structure 244, or to adjust the air pressure supplied to the second sac-like structure 244, so that the first sac-like structure 242 having the receiving coil 203 does not come into close contact with the examination site of the subject 102 (preferably, the subject 102 is not constrained by the flexible band 240).

[0080] Furthermore, since the end points 243A, 243B of the first bag-shaped structure 242 and the second bag-shaped structure 244 are joined together, the first bag-shaped structure 242 extends as the second bag-shaped structure 244 extends.

[0081] By extending the second bag-shaped structure 244 in a curved shape in this manner, the first bag-shaped structure 242 housing the receiving coil 203 can also be extended in a curved shape, making it possible to prepare the receiving coil 203 for wrapping around the examination site or to release the wrapping.

[0082] FIG. 6 is a transition diagram showing an outline of the operation of the flexible band housing the receiving coil and the operation of the bed.

[0083] 6(A) shows a state in which the subject 102 is sitting on the top plate 132 of the bed before the examination. At this time, air is not supplied to the flexible band 240 shown in FIG. 4 and the like. Also, the top plate 132 is located at the lowered end.

[0084] 6(B), the subject 102 lies supine on the top board 132. It is preferable for the operator to adjust the position of the subject 102 lying supine on the top board 132 so that the flexible band 240 can be properly wrapped around the examination site of the subject 102.

[0085] Thereafter, the operator operates an operation unit described later to instruct the flexible band 240 (receiving coil 203) to be wound around the examination site of the subject 102. When the instruction to wind the receiving coil 203 is given, air is first supplied to the second bag-like structure 244 of the flexible band 240, which causes the generally deflated flexible band 240 to expand into a curved shape (FIG. 6(B)).

[0086] Next, as shown in FIG. 6(C), the top board 132 is raised to a height that allows the flexible band 240 to be inserted into and removed from the bore of the gantry 110 of the MRI apparatus. Air is supplied to the third bag-like structure 246 of the flexible band 240, and air is discharged from the second bag-like structure 244, so that the flexible band 240 is automatically wrapped around the examination site of the subject 102. In the example shown in FIG. 6, the examination site of the subject 102 is the head. It is also possible to automatically wrap the flexible band 240 around the examination site of the subject 102 by supplying air to the third bag-like structure 246 without discharging air from the second bag-like structure 244. At this time, it is preferable to appropriately adjust the air pressure supplied to the second bag-like structure 244 and the air pressure supplied to the third bag-like structure 246.

[0087] Next, as shown in Fig. 6(D), the top plate 132 is inserted into the bore of the gantry 110 of the MRI apparatus. This enables an MRI examination of the examination site of the subject 102. Note that the bed and the wrapping of the flexible band 240 in Figs. 6(B) and (C) may be controlled simultaneously.

[0088] After that, when the examination is completed, the control of the bed and the control of the flexible band 240 are performed in the reverse order to that described above.

[0089] FIG. 7 is a diagram showing an example of the drive and control unit of the flexible band shown in FIG. 4, and the receiving coil device of the second embodiment is composed of a flexible band 240, a fluid pressure circuit 250, a control unit 260, and an operating unit 232.

[0090] 7, a part of the outside of the third bag-shaped structure 246 of the flexible band 240 is fixed to the bed 130 (top board 132) by a fixing part 240A. This fixing part 240A may be configured to be detachable from the top board 132.

[0091] The fluid pressure circuit 250 is made up of an air compressor 251 , a first tube 252 , a second tube 254 , a solenoid valve 256 , the pressure sensor 226 , and a relief valve 228 .

[0092] One end of the first tube 252 and the second tube 254 are connected to the air supply and exhaust ports of the second bag-shaped structure 244 and the third bag-shaped structure 246, respectively, and the other end is connected to the air compressor 251 or the exhaust port via an electromagnetic valve 256.

[0093] The solenoid valve 256 is a four-way three-position solenoid valve disposed in the first tube 252 and the second tube 254 .

[0094] When the solenoid 256A is excited, this solenoid valve 256 enables compressed air to be supplied from the air compressor 251 to the third bag-shaped structure 246 via the solenoid valve 256 and the second tube 254, and also enables air to be discharged from the second bag-shaped structure 244 to the atmosphere via the first tube 252 and the solenoid valve 256.

[0095] In addition, when the solenoid 256B is excited, the solenoid valve 256 enables compressed air to be supplied from the air compressor 251 to the second bag-shaped structure 244 via the solenoid valve 256 and the first tube 252, and enables air to be discharged from the third bag-shaped structure 246 to the atmosphere via the second tube 254 and the solenoid valve 256.

[0096] The pressure sensor 226 detects the air pressure supplied from the air compressor 251 to the second bag-like structure 244 or the third bag-like structure 246, and outputs a pressure signal indicating the detected air pressure to the control unit 260.

[0097] The relief valve 228 functions as a safety valve that opens and discharges air when the air pressure supplied to the second bag-like structure 244 or the third bag-like structure 246 becomes abnormal.

[0098] The control unit 260 controls the air compressor 251 and the solenoid valve 256 in response to an instruction to wind the receiving coil 203 or an instruction to unwind the receiving coil 203 from the operation unit 232, and winds the flexible band 240 (the receiving coil 203 around the examination site of the subject 102 or unwinds the receiving coil 203 from the examination site.

[0099] That is, when the control unit 260 receives an instruction to wind the receiving coil 203 from the operation unit 232, it excites the solenoid 256A of the solenoid valve 256, then drives the air compressor 251, and controls the drive of the pressure increase / reduction pump 221 so that compressed air is discharged from the air compressor 251.

[0100] As a result, the compressed air discharged from the air compressor 251 is supplied to the third bag-shaped structure 246 via the solenoid valve 256 and the second tube 254, and the air in the second bag-shaped structure 244 is discharged via the first tube 252 and the solenoid valve 256.

[0101] Thereafter, when the control unit 260 detects that the pressure inside the third bag-shaped structure portion 246 of the flexible band 240 has reached a preset reference pressure based on the detection signal of the pressure sensor 226, it stops the air compressor 251, and then demagnetizes the solenoid 256A of the solenoid valve 256, returning the spool of the solenoid valve 256 to the position shown in FIG. 7.

[0102] As described above, when compressed air is supplied to third bag-shaped structure 246, a difference in length occurs between the outer circumferential side and the inner circumferential side of third bag-shaped structure 246, and third bag-shaped structure 246 curves inward as shown in Fig. 4, and flexible band 240 (receiving coil 203) is wrapped around subject 102. Note that, since the length of the inner circumferential side of third bag-shaped structure 246 is restricted by the length of second bag-shaped structure 244, when compressed air is supplied into third bag-shaped structure 246, a difference in length occurs between the outer circumferential side and the inner circumferential side of third bag-shaped structure 246.

[0103] On the other hand, when the control unit 260 receives an instruction to unwind the receiving coil 203 from the operation unit 232, it excites the solenoid 256B of the solenoid valve 256, then drives the air compressor 251, and controls the drive of the pressure increase / reduction pump 221 so that compressed air is discharged from the air compressor 251.

[0104] As a result, the compressed air discharged from the air compressor 251 is supplied to the second bag-shaped structure 244 via the solenoid valve 256 and the first tube 252, and the air in the third bag-shaped structure 246 is discharged via the second tube 254 and the solenoid valve 256.

[0105] Thereafter, when the control unit 260 detects that the pressure in the second bag-shaped structure portion 244 of the flexible band 240 has reached the reference pressure based on the detection signal of the pressure sensor 226, it stops the air compressor 251, and then demagnetizes the solenoid 256A of the solenoid valve 256, returning the spool of the solenoid valve 256 to the position shown in FIG. 7.

[0106] While inner end points 243A, 243B of second sac-shaped structure 244 are constrained by first sac-shaped structure 242, inner end points 243A, 243B of second sac-shaped structure 244 are not constrained by third sac-shaped structure 246, and therefore a difference occurs between the inner and outer lengths of second sac-shaped structure 244, and second sac-shaped structure 244 deforms to curve inward. However, second sac-shaped structure 244 extends (spreads) in a curved shape so as not to constrain the examination site, and thus the winding of receive coil 203 around the examination site is released.

[0107] 7, a signal cable for acquiring an NMR signal from the receiving coil 203 is omitted, but the signal cable and the first tube 252 and the second tube 254 are wired and piped so as not to impede the movement of the bed top 132. In addition, in the fluid pressure circuit 250 shown in FIG. 7, an accumulator may be provided on the discharge port side of the air compressor 251, and the air compressor 251 may be driven when the compressed air accumulated in the accumulator becomes equal to or lower than a reference pressure.

[0108] [Other embodiments] The control units 230 and 260 shown in Figures 3 and 7 control the fluid pressure circuits 220 and 250 in response to an instruction to wind the receiving coil 203 or an instruction to unwind the receiving coil 203 from the operation unit 232 operated by the operator, and cause the receiving coil 203 to be wound around the subject and to be unwound. However, without being limited to this, the fluid pressure circuits 220 and 250 may also be controlled by an instruction to operate the bed 130 or a predetermined timing of the operation of the bed as a trigger.

[0109] For example, when the control unit 140 shown in FIG. 2 receives an instruction to raise the bed 130 from the operation unit 150 and controls the raising of the bed 130, the control units 230 and 260 may receive the instruction to raise the bed 130 as an instruction to wind the receiving coil and control the fluid pressure circuits 220 and 250, or may receive a first timing in the control of the raising of the bed 130 (for example, the timing when the raising of the bed 130 is completed) as an instruction to wind the receiving coil and control the fluid pressure circuits 220 and 250.

[0110] Similarly, when the control unit 140 shown in FIG. 2 receives an instruction from the operation unit 150 to pull out the bed 130 (top plate 132) from the bore 120 of the gantry 110 of the MRI apparatus 100 and controls the pulling out of the top plate 132 from the bore 120, the control units 230 and 260 may receive the instruction to pull out the bed 130 as an instruction to unwind the receiving coil and control the hydraulic circuits 220 and 250, or may receive a second timing in the control of the pulling out of the bed 130 (for example, the timing when the pulling out of the top plate 132 of the bed 130 from the gantry 110 is completed) as an instruction to unwind the receiving coil and control the hydraulic circuits 220 and 250.

[0111] According to this, the operator does not need to use the operation unit to give instructions to wind the receiving coil or to unwind the receiving coil, which further reduces the burden on the operator.

[0112] In addition, as shown in Figures 4 and 5, the flexible band 240 in the second embodiment has a first bag-shaped structure 242 as the first layer at the innermost circumference, a second bag-shaped structure 244 for stretching the flexible band 240 as the second layer on the outer periphery of the first bag-shaped structure 242, and a third bag-shaped structure 246 for curving the flexible band 240 as the third layer on the outer periphery of the second bag-shaped structure 244. However, this is not limited to the above, and the third bag-shaped structure 246 may be provided between the first bag-shaped structure 242 and the second bag-shaped structure 244.

[0113] That is, the first bladder structure 242 of the first layer may be disposed on the innermost periphery of the flexible band 240, the second bladder structure 244 and the third bladder structure 246 disposed on the outer periphery of the first bladder structure 242 may be reversed, and the third layer and the second layer may be overlapped and joined in this order on the outer periphery of the first bladder structure 242 (first layer). In this case, the length of the first bladder structure 242 of the first layer may be made shorter than the lengths of the second bladder structure 244 and the third bladder structure 246, the lengths of the second bladder structure 244 and the third bladder structure 246 may be made the same, and both end points of each bladder structure may be fixed as shown in FIG. 5.

[0114] Moreover, since the receiving coil 203 is housed in the first bag-shaped structure 242 on the innermost periphery side of the flexible band 240, the receiving coil 203 can be brought close to the examination site of the subject 102 when the flexible band 240 is bent.

[0115] [others] In this embodiment, one flexible band containing a receiving coil used for head examination is provided on the bed, but two or more flexible bands used for examination of other examination parts of the subject (chest, abdomen, joints of the limbs, etc.) may be provided on the bed, or a desired flexible band may be attached to the bed. In this case, the fluid pressure circuit and control unit for driving the flexible band can be used in common for each flexible band.

[0116] In addition, in this embodiment, a gas such as air is supplied as the fluid to be supplied to the flexible band, but this is not limited to this, and a liquid such as water may also be supplied, and the type of fluid is not important.

[0117] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0118] 100...MRI device 102...Subject 110…Gantry 120…Bore 130…Bed 132…Tabletop 140, 230, 260...Control unit 150.232…Operation unit 200...Receiving coil device 203…Receiving coil 210…Flexible band 220...Fluid pressure circuit 240…Flexible band

Claims

1. A receiving coil device provided in a magnetic resonance imaging apparatus for receiving a nuclear magnetic resonance signal, A receiving coil for receiving the nuclear magnetic resonance signal; a flexible band that houses the receiving coil and has a portion fixed to a bed, the flexible band changing its shape by supplying and / or discharging a fluid, and winding the receiving coil around an examination site of a subject on the bed or releasing the winding of the receiving coil; A receiving coil device comprising:

2. The flexible band is a first layer that houses the receiving coil and a second layer that has a bag-shaped structure and is curved or expanded by the fluid supplied to or discharged from the bag-shaped structure, the first layer being joined to the second layer; When the fluid is supplied to the bag-like structure, the bag-like structure is curved to wrap the receiving coil around the examination site, and when the fluid is discharged from the bag-like structure, the receiving coil is released from the wrapping.

2. The receive coil device according to claim 1.

3. The first layer has a first bag-shaped structure that houses the receiving coil.

3. The receive coil device according to claim 2.

4. The first layer is disposed on an inner circumferential side of the curved flexible band.

3. The receive coil device according to claim 2.

5. The flexible band is a first layer that houses the receiving coil, a second layer that has a second bag-like structure and is expanded by the fluid supplied to the second bag-like structure, and a third layer that has a third bag-like structure and is curved by the fluid supplied to the third bag-like structure, and the third layer is joined together; When the fluid is discharged from the third bag-like structure and the fluid is supplied to the second bag-like structure, the receiving coil is stretched to be able to be released from being wound around at least the examination site, and when the fluid is supplied to the third bag-like structure, the receiving coil is curved to wind the receiving coil around the examination site.

2. The receive coil device according to claim 1.

6. The flexible band is bonded by overlapping the first layer, the second layer, and the third layer in this order from the innermost periphery side of the flexible band, or the second layer, the first layer, and the third layer in this order from the innermost periphery side of the flexible band, The receive coil device according to claim 5 .

7. The first layer is disposed on the innermost side of the curved flexible band, and the second layer and the third layer are disposed on the outer side of the first layer. The receive coil device according to claim 5 .

8. The first layer has a first bag-shaped structure that houses the receiving coil. The receive coil device according to claim 5 .

9. a fluid pressure circuit including a fluid pressure source that supplies and / or discharges the fluid, a tube disposed between the fluid pressure source and the bag-like structure, and an electromagnetic valve disposed in the tube and that switches the direction of the fluid flowing through the tube; a control unit for controlling the fluid pressure source and the solenoid valve, When the control unit receives an instruction to wind the receiving coil, the control unit controls the fluid pressure source and the solenoid valve to supply the fluid from the fluid pressure source to the bag-shaped structure via the solenoid valve and the tube, thereby winding the receiving coil around the examination site, and when the control unit receives an instruction to unwind the receiving coil, the control unit discharges the fluid from the bag-shaped structure via the tube and the solenoid valve, thereby unwinding the receiving coil from the examination site.

3. The receive coil device according to claim 2.

10. a fluid pressure circuit including a fluid pressure source that supplies and / or discharges the fluid, a first tube and a second tube that are disposed between the fluid pressure source and the second bag-like structure and a solenoid valve that is disposed in the first tube and the second tube and that switches a direction of the fluid flowing through the first tube and the second tube; a control unit for controlling the fluid pressure source and the solenoid valve, When the control unit receives an instruction to wind the receiving coil, the control unit controls the fluid pressure source and the solenoid valve to discharge the fluid from the second bag-like structure via the first tube and the solenoid valve, and to supply the fluid from the fluid pressure source to the third bag-like structure via the solenoid valve and the second tube, thereby winding the receiving coil around the examination site; when the control unit receives an instruction to unwind the receiving coil, the control unit controls the fluid to discharge the fluid from the third bag-like structure via the second tube and the solenoid valve, and to supply the fluid from the fluid pressure source to the second bag-like structure via the solenoid valve and the first tube, thereby unwinding the receiving coil from the examination site. The receive coil device according to claim 5 .

11. The control unit receives an instruction to lift the bed or a first timing in the control of lifting the bed as an instruction to wind the receiving coil. The receive coil device according to claim 9.

12. the control unit accepts, as an instruction to unwind the receive coil, an instruction to withdraw the bed from a gantry of the magnetic resonance imaging apparatus or a second timing in control of withdrawing the bed. The receive coil device according to claim 9.

13. A magnetic resonance imaging apparatus comprising the receive coil device according to any one of claims 1 to 12.

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