CN210243815U - Eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system - Google Patents
Eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system Download PDFInfo
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- CN210243815U CN210243815U CN201920785001.XU CN201920785001U CN210243815U CN 210243815 U CN210243815 U CN 210243815U CN 201920785001 U CN201920785001 U CN 201920785001U CN 210243815 U CN210243815 U CN 210243815U
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Abstract
The utility model provides an eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system, wherein a fixed bracket is arranged on a supporting bracket, and a radio frequency receiving coil mounting bracket is arranged on the fixed bracket and is arranged in a magnet of the 7.0T animal experiment magnetic resonance imaging system when in use; the first to sixth radio frequency receiving coils are all arranged on the radio frequency receiving coil mounting bracket, the radio frequency receiving coil mounting bracket is provided with a coil symmetric central point, the first to sixth radio frequency receiving coils are arranged pairwise along the left-right direction, the up-down direction and the front-back direction respectively and are symmetrically arranged at equal intervals relative to the coil symmetric central point, and 6 water films are arranged in the first to sixth radio frequency receiving coils respectively. The utility model discloses a vortex measuring device measuring signal SNR for 7.0T animal experiment magnetic resonance imaging system is good, measures portably, quick, accurate, design benefit, and the structure is succinct, makes portably, and is with low costs, is suitable for extensive popularization and application.
Description
Technical Field
The utility model relates to the technical field of medical equipment, in particular to magnetic resonance imaging system technical field specifically indicates a vortex measuring device that is used for 7.0T animal experiment magnetic resonance imaging system.
Background
Magnetic Resonance Imaging (MRI) is one application of Nuclear Magnetic Resonance (NMR) in medicine. The main magnet system of the magnetic resonance imaging system generates a strong, uniform magnetic field (referred to as the MRI system main magnetic field-B0). The hydrogen nuclei in the human body are spin polarized under the B0 field. Magnetically polarized hydrogen nuclear spins produce magnetic moments in the human body. In the absence of excitation by an external magnetic field other than B0, the magnetic moment is in a steady state, coaxial with the direction of the main magnetic field B0, and does not yield useful information.
The radio frequency system is divided into two parts of radio frequency transmission and radio frequency reception. A Radio Frequency (RF) transmitting coil transmits a radio frequency magnetic field (called an excitation magnetic field or a B1 magnetic field), magnetic moments in a human body are excited to generate a nuclear magnetic resonance signal, and the nuclear magnetic resonance signal is acquired by a radio frequency receiving part and is integrated with electronic circuits and software to finally acquire data and images of a magnetic resonance imaging system (MRI).
Gradient systems are mainly based on the application of currents to gradient coils, which generate time-varying gradient magnetic fields, which are mainly used for localization of signals of the MRI system.
In particular, the gradient coil comprises three coils that can generate orthogonal magnetic fields, namely three coils of X, Y and Z, which refer to imaginary orthogonal axes in a magnetic resonance imaging system (MRI), wherein the X-axis is a horizontal axis extending from the center of the magnetic field, the Y-axis is a vertical axis extending from the center of the magnetic field, and the Z-axis is an axis coaxial with the main axis of the bore of the main magnet. In the imaging process of a magnetic resonance system, current in a gradient coil is rapidly switched along with time to form a gradient field which changes in real time, and as metal components, such as a shell of a superconducting magnet, are arranged in the system, eddy current can be generated in the metal components according to a Faraday electromagnetic induction law, and the eddy current can generate a magnetic field which changes constantly in space and time, so that the gradient field of the system per se is seriously deformed, and the MRI image quality is influenced. Therefore, solving the eddy current problem is one of the keys of the magnetic resonance imaging system.
In order to reduce the influence of eddy currents on the quality of MRI images, the most common method used at present is a gradient waveform pre-emphasis method, which corrects the gradient waveforms emitted by a pulse sequence by pre-emphasis so that the actually generated gradient fields are closer to the ideal shape. Gradient waveform pre-emphasis performs pre-emphasis correction on a gradient waveform by using a known mathematical model, wherein the commonly accepted model is a multi-exponential function model, and the amplitude and the time constant of an exponential function are used as parameters for correcting the gradient waveform. The amplitude and time constants of these exponential functions are obtained by measuring eddy currents, and it is common practice to apply a gradient pulse to a sample, excite the sample with a radio frequency pulse after a certain time to generate a Free Induction Decay (FID) signal whose phase information is a function of time, and then fit the function of time with a set of multi-exponential functions to obtain the desired pre-emphasis correction parameters, which are combined with the gradient waveform output to achieve eddy current pre-emphasis compensation.
The specific operation process is that a water film is placed in a volume receiving coil, generally, the water film is placed in two symmetrical test points respectively in the left direction (X), the right direction (X), the up direction (Y) and the front direction (Z) by taking the center of a magnet as the center, 6 test points are totally obtained, a Free Induction Decay (FID) signal is obtained from each test point, after one test point is finished, the water film is moved to the other test point, and the multi-exponential function fitting can not be carried out until all data on all the 6 test points are completely obtained. This mode of operation presents a number of problems and inconveniences:
1. the position of the water film is difficult to ensure to be accurate, and two symmetrical point positions are required to be accurate in the vortex compensation fitting process, otherwise, the compensation result is influenced.
2. The size of the water film is selected, if the water film is too large, the influence of shimming factors can cause inaccurate measuring results, and if the water film is too small, Free Induction Decay (FID) signals received by the volume coil are weaker, the signal-to-noise ratio of the signals is poorer, and the inaccurate measuring results can also be caused.
3. The point-by-point measurement can lead to the overlong whole eddy current measurement time, and then the fitting compensation time is added, so that the whole eddy current compensation process is long and complicated.
4. In clinical MRI systems such as 1.5T or 3.0T, the internal space of a general volume receiving coil is a 30cm spherical area, and it is difficult to operate to move the water film to a precise position in the space each time, while the internal space of a receiving coil of a 7.0T animal experiment MRI system is only a 5cm spherical area, and it is more difficult to move the water film to a precise position in the space.
Therefore, it is necessary to provide an eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system, which has a good signal-to-noise ratio of the measured signal and is simple, fast and accurate in measurement.
SUMMERY OF THE UTILITY MODEL
In order to overcome the defects in the prior art, the utility model discloses an object is to provide an eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system, its measuring signal SNR is good, measures portably, fast, accurate, is suitable for extensive popularization and application.
Another object of the utility model is to provide a vortex measuring device for 7.0T animal experiment magnetic resonance imaging system, its design benefit, the structure is succinct, makes portably, and is with low costs, is suitable for extensive popularization and application.
In order to achieve the above object, the utility model discloses an eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system, its characteristics are, including radio frequency receiving coil installing support, fixed bolster and support holder, first radio frequency receiving coil, second radio frequency receiving coil, third radio frequency receiving coil, fourth radio frequency receiving coil, fifth radio frequency receiving coil, sixth radio frequency receiving coil and 6 water films, wherein:
the fixing support is arranged on the supporting support, and the radio frequency receiving coil mounting support is arranged on the fixing support and is used for being placed in a magnet of a 7.0T animal experiment magnetic resonance imaging system when in use;
the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are all arranged on the radio frequency receiving coil mounting bracket, the radio frequency receiving coil mounting bracket is provided with a coil symmetric center point, the first radio frequency receiving coil and the second radio frequency receiving coil are arranged along the left-right direction and are arranged in point symmetry relative to the coil symmetric center point, the third radio frequency receiving coil and the fourth radio frequency receiving coil are arranged along the up-down direction and are arranged in point symmetry relative to the coil symmetric center point, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are arranged along the front-back direction and are arranged in point symmetry relative to the coil symmetric center point, and the distance between the first radio frequency receiving coil and the second radio frequency receiving coil, The distance between the third radio frequency receiving coil and the fourth radio frequency receiving coil is equal to the distance between the fifth radio frequency receiving coil and the sixth radio frequency receiving coil, and the 6 water films are respectively arranged in the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil.
Preferably, the rf receiving coil mounting bracket includes a central plate, an upper plate, a lower plate, a front plate, a rear plate, a left plate, and a right plate, the central plate, the upper plate, the lower plate, the front plate, and the rear plate are all disposed along the front-rear direction, the coil symmetry point is located at the center of the central plate, the upper plate and the lower plate are disposed at the upper end and the lower end of the central plate, respectively, the front plate and the rear plate are disposed at the front end and the rear end of the central plate, respectively, the left plate and the right plate are disposed along the left-right direction and disposed on the left side and the right side of the central plate, respectively, and the first rf receiving coil, the second rf receiving coil, the third rf receiving coil, the fourth rf receiving coil, the fifth rf receiving coil, and the sixth rf receiving coil are disposed on the left plate, the right side, respectively, The right plate, the upper plate, the lower plate, the front plate and the rear plate.
Preferably, the radio frequency receiving coil mounting bracket is provided with a first mounting hole, a second mounting hole, a third mounting hole, a fourth mounting hole, a fifth mounting hole and a sixth mounting hole, and the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are respectively arranged in the first mounting hole, the second mounting hole, the third mounting hole, the fourth mounting hole, the fifth mounting hole and the sixth mounting hole.
Preferably, the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are all solenoid receiving coils.
Preferably, the fixing support is a circular tube, and the circular tube is arranged along the front-back direction.
Preferably, the support bracket is a sector plate, the sector plate is arranged along the left-right direction, and the lower part of the sector plate is large and the upper part of the sector plate is small.
More preferably, the diameter of the circle on which the sector-shaped plate member is located is the same as the inner diameter of the magnet.
Preferably, the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further comprises position marking points, and the position marking points are arranged on the fixing bracket along the left-right direction and used for aligning with corresponding position marking points on the magnet so as to accurately position the front-back direction. Preferably, the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further includes a first-stage preamplifier, a second-stage preamplifier, a third-stage preamplifier, a fourth-stage preamplifier, a fifth-stage preamplifier and a sixth-stage preamplifier, wherein the first-stage preamplifier, the second-stage preamplifier, the third-stage preamplifier, the fourth-stage preamplifier, the fifth-stage preamplifier and the sixth-stage preamplifier are all mounted on the fixed support and are respectively in signal connection with the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil.
Preferably, the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further includes a first printed circuit board, a second printed circuit board, a third printed circuit board, a fourth printed circuit board, a fifth printed circuit board and a sixth printed circuit board, the first printed circuit board, the second printed circuit board, the third printed circuit board, the fourth printed circuit board, the fifth printed circuit board and the sixth printed circuit board are all disposed on the rf receiving coil mounting bracket, and the first rf receiving coil, the second rf receiving coil, the third rf receiving coil, the fourth rf receiving coil, the fifth rf receiving coil and the sixth rf receiving coil are respectively disposed on the first printed circuit board, the second printed circuit board, the third printed circuit board, the fourth rf receiving coil, the fifth rf receiving coil and the sixth rf receiving coil, The fourth printed wiring board, the fifth printed wiring board, and the sixth printed wiring board.
The beneficial effects of the utility model mainly lie in:
1. the utility model discloses a fixed bolster that is used for 7.0T animal experiment magnetic resonance imaging system's vortex measuring device sets up on the support holder, and the radio frequency receiving coil installing support is installed and is arranged in 7.0T animal experiment magnetic resonance imaging system's magnet when being used on the fixed bolster; the first, the second, the third, the fourth, the fifth and the sixth radio frequency receiving coils are all arranged on a radio frequency receiving coil mounting bracket, the radio frequency receiving coil mounting bracket is provided with a coil symmetrical center point, the first and the second radio frequency receiving coils are arranged along the left-right direction and are point-symmetrically arranged relative to the coil symmetrical center point, the third and the fourth radio frequency receiving coils are arranged along the up-down direction and are point-symmetrically arranged relative to the coil symmetrical center point, the fifth and the sixth radio frequency receiving coils are arranged along the front-back direction and are point-symmetrically arranged relative to the coil symmetrical center point, the distance between the first and the second radio frequency receiving coils, the distance between the third and the fourth radio frequency receiving coils and the distance between the fifth and the sixth radio frequency receiving coils are equal, 6 water films are respectively arranged in the first, the second, the third, the fourth, the fifth and the sixth radio frequency receiving coils, when in use, the radio frequency receiving coil mounting bracket is arranged in a magnet of a 7.0T animal experiment magnetic resonance imaging system, and the positions of the fixing support and the supporting support are adjusted to ensure that the coil symmetric center point of the radio frequency receiving coil mounting support is positioned at the center of the magnet, and the left-right direction, the up-down direction and the front-back direction are superposed with the X axis, the Y axis and the Z axis of a magnetic field generated by the magnet, so that the signal-to-noise ratio of a measuring signal is good, the measurement is simple, convenient, rapid and accurate, and the method is suitable for large-scale popularization and application.
2. The utility model discloses a fixed bolster that is used for 7.0T animal experiment magnetic resonance imaging system's vortex measuring device sets up on the support holder, and the radio frequency receiving coil installing support is installed and is arranged in 7.0T animal experiment magnetic resonance imaging system's magnet when being used on the fixed bolster; the first, the second, the third, the fourth, the fifth and the sixth radio frequency receiving coils are all arranged on a radio frequency receiving coil mounting bracket, the radio frequency receiving coil mounting bracket is provided with a coil symmetrical center point, the first and the second radio frequency receiving coils are arranged along the left-right direction and are point-symmetrically arranged relative to the coil symmetrical center point, the third and the fourth radio frequency receiving coils are arranged along the up-down direction and are point-symmetrically arranged relative to the coil symmetrical center point, the fifth and the sixth radio frequency receiving coils are arranged along the front-back direction and are point-symmetrically arranged relative to the coil symmetrical center point, the distance between the first and the second radio frequency receiving coils, the distance between the third and the fourth radio frequency receiving coils and the distance between the fifth and the sixth radio frequency receiving coils are equal, 6 water films are respectively arranged in the first, the second, the third, the fourth, the fifth and the sixth radio frequency receiving coils, when in use, the radio frequency receiving coil mounting bracket is arranged in a magnet of a 7.0T animal experiment magnetic resonance imaging system, and the coil symmetric center point of the radio frequency receiving coil mounting bracket is positioned at the center of the magnet by adjusting the positions of the fixing bracket and the supporting bracket, and the left-right direction, the up-down direction and the front-back direction are coincided with the X axis, the Y axis and the Z axis of the magnetic field generated by the magnet.
These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, the accompanying drawings and the appended claims, wherein like reference numerals refer to corresponding parts throughout the several views, and wherein like reference numerals refer to like parts throughout the several views.
Drawings
Fig. 1 is a schematic perspective view of an embodiment of the eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system according to the present invention.
Fig. 2 is a perspective view of the radio frequency receive coil mounting bracket, mounting bracket and support bracket of the embodiment shown in fig. 1.
Fig. 3 is a front view of the first rf receive coil and the first printed wiring board of the embodiment shown in fig. 1.
(symbol description)
1, mounting a bracket for a radio frequency receiving coil; 2, fixing a bracket; 3 supporting the bracket; 4 a first radio frequency receive coil; 5 a second radio frequency receiving coil; 6 a third radio frequency receiving coil; 7 a fourth radio frequency receive coil; 8 a fifth radio frequency receive coil; 9 a sixth radio frequency receive coil; 10, water film; 11 a central plate; 12, mounting a plate; 13 a lower plate; 14 a front plate; 15 a rear plate; 16 left plate; 17 a right plate; 18 a first mounting hole; 19 a second mounting hole; 20 a third mounting hole; 21 a fourth mounting hole; 22 a fifth mounting hole; 23 a sixth mounting hole; 24 position mark points; 25 a first primary preamplifier; 26 a third stage preamplifier; 27 a fifth stage preamplifier; 28 a first printed wiring board; 29 a second printed wiring board; 30 a third printed wiring board; 31 a fourth printed wiring board; 32 a fifth printed wiring board; 33 sixth printed wiring board.
Detailed Description
In order to clearly understand the technical contents of the present invention, the following embodiments are specifically illustrated in detail.
Please refer to fig. 1-3, in an embodiment of the present invention, the eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system comprises a radio frequency receiving coil mounting bracket 1, a fixing bracket 2, a supporting bracket 3, a first radio frequency receiving coil 4, a second radio frequency receiving coil 5, a third radio frequency receiving coil 6, a fourth radio frequency receiving coil 7, a fifth radio frequency receiving coil 8, a sixth radio frequency receiving coil 9, and 6 water films 10, wherein:
the fixed support 2 is arranged on the supporting support 3, and the radio frequency receiving coil mounting support 1 is arranged on the fixed support 2 and used for being placed in a magnet of a 7.0T animal experiment magnetic resonance imaging system when in use;
the first radio frequency receiving coil 4, the second radio frequency receiving coil 5, the third radio frequency receiving coil 6, the fourth radio frequency receiving coil 7, the fifth radio frequency receiving coil 8 and the sixth radio frequency receiving coil 9 are all arranged on the radio frequency receiving coil mounting bracket 1, the radio frequency receiving coil mounting bracket 1 has a coil symmetry center point (not shown in the figure), the first radio frequency receiving coil 4 and the second radio frequency receiving coil 5 are arranged along the left-right direction and are point-symmetrically arranged relative to the coil symmetry center point, the third radio frequency receiving coil 6 and the fourth radio frequency receiving coil 7 are arranged along the up-down direction and are point-symmetrically arranged relative to the coil symmetry center point, the fifth radio frequency receiving coil 8 and the sixth radio frequency receiving coil 9 are arranged along the front-back direction and are point-symmetrically arranged relative to the coil symmetry center point, and the distance between the first radio frequency receiving coil 4 and the second radio frequency receiving coil 5, the distance between the third radio frequency receiving coil 6 and the fourth radio frequency receiving coil 7, and the distance between the fifth radio frequency receiving coil 8 and the sixth radio frequency receiving coil 9 are equal, and 6 water films 10 are respectively arranged in the first radio frequency receiving coil 4, the second radio frequency receiving coil 5, the third radio frequency receiving coil 6, the fourth radio frequency receiving coil 7, the fifth radio frequency receiving coil 8, and the sixth radio frequency receiving coil 9.
The rf receiver coil mounting bracket 1 may have any suitable configuration, and as shown in fig. 1 to 2, in an embodiment of the present invention, the rf receiver coil mounting bracket 1 includes a central plate 11, an upper plate 12, a lower plate 13, a front plate 14, a rear plate 15, a left plate 16 and a right plate 17, the central plate 11, the upper plate 12, the lower plate 13, the front plate 14 and the rear plate 15 are all disposed along the front-rear direction, the coil symmetry center point is located at the center of the central plate 11, the upper plate 12 and the lower plate 13 are respectively disposed at the upper end and the lower end of the central plate 11, the front plate 14 and the rear plate 15 are respectively disposed at the front end and the rear end of the central plate 11, the left plate 16 and the right plate 17 are both disposed along the left-right direction and are respectively disposed at the left side and the right side of the central plate 11, the first radio frequency receiving coil 4, the second radio frequency receiving coil 5, the third radio frequency receiving coil 6, the fourth radio frequency receiving coil 7, the fifth radio frequency receiving coil 8, and the sixth radio frequency receiving coil 9 are respectively disposed on the left plate 16, the right plate 17, the upper plate 12, the lower plate 13, the front plate 14, and the rear plate 15.
The first rf receiving coil 4, the second rf receiving coil 5, the third rf receiving coil 6, the fourth rf receiving coil 7, the fifth rf receiving coil 8 and the sixth rf receiving coil 9 are all disposed on the rf receiving coil mounting bracket 1, and any suitable structure may be adopted, and preferably, the rf receiving coil mounting bracket 1 is provided with a first mounting hole 18, a second mounting hole 19, a third mounting hole 20, a fourth mounting hole 21, a fifth mounting hole 22 and a sixth mounting hole 23, and the first rf receiving coil 4, the second rf receiving coil 5, the third rf receiving coil 6, the fourth rf receiving coil 7, the fifth rf receiving coil 8 and the sixth rf receiving coil 9 are respectively disposed in the first mounting hole 18, the second mounting hole 19, the fifth mounting hole 19, the sixth mounting hole 23, The third mounting hole 20, the fourth mounting hole 21, the fifth mounting hole 22, and the sixth mounting hole 23. Referring to fig. 1 to 2, in an embodiment of the present invention, in a case that the rf receiving coil mounting bracket 1 includes a central plate 11, an upper plate 12, a lower plate 13, a front plate 14, a rear plate 15, a left plate 16, and a right plate 17, the first mounting hole 18, the second mounting hole 19, the third mounting hole 20, the fourth mounting hole 21, the fifth mounting hole 22, and the sixth mounting hole 23 are respectively disposed in the left plate 16, the right plate 17, the upper plate 12, the lower plate 13, the front plate 14, and the rear plate 15.
The first rf receiving coil 4, the second rf receiving coil 5, the third rf receiving coil 6, the fourth rf receiving coil 7, the fifth rf receiving coil 8 and the sixth rf receiving coil 9 may have any suitable shape, as shown in fig. 1 and 3, in a specific embodiment of the present invention, the first rf receiving coil 4, the second rf receiving coil 5, the third rf receiving coil 6, the fourth rf receiving coil 7, the fifth rf receiving coil 8 and the sixth rf receiving coil 9 are solenoid receiving coils.
The water film 10 may have any suitable shape, as shown in fig. 1 and 3, and in an embodiment of the present invention, the water film 10 is a cylindrical water film.
The size of cylindrical water film can be confirmed as required in the utility model discloses a specific embodiment, the diameter of cylindrical water film is 2.5mm, the height of cylindrical water film 10 is 3.5 mm.
The fixing bracket 2 may have any suitable shape, as shown in fig. 1 to 2, in an embodiment of the present invention, the fixing bracket 2 is a circular tube, and the circular tube is disposed along the front-back direction.
The support frame 3 may have any suitable shape, as shown in fig. 1-2, in an embodiment of the present invention, the support frame 3 is a sector plate, the sector plate is disposed along the left-right direction, and the lower portion of the sector plate is larger than the upper portion thereof.
The size of the sector plate can be determined according to the requirement, and in a specific embodiment of the present invention, the diameter of the circle where the sector plate is located is the same as the inner diameter of the magnet. Like this, because the magnet is cylinder transmitting coil, because the diameter of fan-shaped plate place circle with the internal diameter of magnet is the same, when will the utility model discloses when arranging cylinder transmitting coil in, fan-shaped plate is put in the bottom, can just in time coincide with cylinder transmitting coil, has guaranteed that the center of whole device lies in cylinder transmitting coil's center on X and Y plane, consequently fan-shaped plate can realize the position of pinpointing X and Y direction.
The number of the sector plates can be determined as required, please refer to fig. 1 to 2, in a specific embodiment of the present invention, the number of the sector plates is 2, and the 2 sector plates are arranged at intervals along the front-back direction.
In order to accurately position the front-back direction, please refer to fig. 1-2, in an embodiment of the present invention, the eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system further includes a position mark point 24, and the position mark point 24 is disposed on the fixing bracket 2 along the left-right direction and used for aligning with a corresponding position mark point on the magnet, so as to accurately position the front-back direction. Because the magnet is cylinder transmitting coil, has a corresponding position mark point on the cylinder transmitting coil, and these two position mark points align, just represent the utility model discloses it is unanimous with cylinder transmitting coil's center at the center of Z direction, realize the accurate positioning of Z direction.
The position mark points 24 may have any suitable shape, as shown in fig. 1-2, and in an embodiment of the present invention, in the case that the fixing bracket 2 is a circular tube, the position mark points are circular arcs arranged on the outer side surface of the circular tube along the circumferential direction of the circular tube.
The eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system may further include any other suitable configuration, and preferably, the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further includes a first-stage preamplifier 25, a second-stage preamplifier (not shown), a third-stage preamplifier 26, a fourth-stage preamplifier (not shown), a fifth-stage preamplifier 27 and a sixth-stage preamplifier (not shown), wherein the first-stage preamplifier 25, the second-stage preamplifier, the third-stage preamplifier 26, the fourth-stage preamplifier, the fifth-stage preamplifier 27 and the sixth-stage preamplifier are all mounted on the fixed bracket 2 and respectively connected to the first rf receiving coil 4, the second rf receiving coil 4, the third rf receiving coil 26, the fourth rf receiving coil 4, the fourth rf receiving coil 27, the fifth rf receiving coil 27 and the sixth rf receiving coil 2 in signal connection, The second radio frequency receiving coil 5, the third radio frequency receiving coil 6, the fourth radio frequency receiving coil 7, the fifth radio frequency receiving coil 8 and the sixth radio frequency receiving coil 9. Referring to fig. 1, in an embodiment of the present invention, when the fixing bracket 2 is a circular tube, the first stage preamplifier 25, the second stage preamplifier, the third stage preamplifier 26, the fourth stage preamplifier, the fifth stage preamplifier 27 and the sixth stage preamplifier are uniformly distributed on the outer side surface of the circular tube along the circumferential direction of the circular tube.
The eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system may further include any other suitable configuration, and preferably, the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further includes a first printed circuit board 28, a second printed circuit board 29, a third printed circuit board 30, a fourth printed circuit board 31, a fifth printed circuit board 32, and a sixth printed circuit board 33, the first printed circuit board 28, the second printed circuit board 29, the third printed circuit board 30, the fourth printed circuit board 31, the fifth printed circuit board 32, and the sixth printed circuit board 33 are all disposed on the rf receiving coil mounting bracket 1, and the first rf receiving coil 4, the second rf receiving coil 5, the third rf receiving coil 6, the fourth rf receiving coil 7, the rf receiving coil 5, the rf receiving coil 6, the rf receiving coil 7, and the rf receiving coil 33 are all disposed on the rf receiving coil mounting bracket 1, The fifth radio frequency receiving coil 8 and the sixth radio frequency receiving coil 9 are respectively disposed on the first printed wiring board 28, the second printed wiring board 29, the third printed wiring board 30, the fourth printed wiring board 31, the fifth printed wiring board 32, and the sixth printed wiring board 33. Referring to fig. 1 and 3, in an embodiment of the present invention, in the case that the eddy current measuring device for the 7.0T animal experiment magnetic resonance imaging system further includes a first stage preamplifier 25, a second stage preamplifier, a third stage preamplifier 26, a fourth stage preamplifier, a fifth stage preamplifier 27 and a sixth stage preamplifier, the first, second, third, fourth, fifth, and sixth primary preamplifiers 25, 26, 27 are respectively connected to the first, second, third, fourth, fifth, and sixth printed circuit boards 28, 29, 30, 31, 32, and 33 by signals.
The first printed circuit board 28, the second printed circuit board 29, the third printed circuit board 30, the fourth printed circuit board 31, the fifth printed circuit board 32 and the sixth printed circuit board 33 are all disposed on the radio frequency receiving coil mounting bracket 1, and any suitable structure may be adopted, and more preferably, the radio frequency receiving coil mounting bracket 1 is provided with a first mounting groove (not shown in the figure), a second mounting groove (not shown in the figure), a third mounting groove (not shown in the figure), a fourth mounting groove (not shown in the figure), a fifth mounting groove (not shown in the figure) and a sixth mounting groove (not shown in the figure), and the first printed circuit board 28, the second printed circuit board 29, the third printed circuit board 30, the fourth printed circuit board 31, the fifth printed circuit board 32 and the sixth printed circuit board 33 are respectively mounted in the first mounting groove, The second mounting groove, the third mounting groove, the fourth mounting groove, the fifth mounting groove and the sixth mounting groove. Referring to fig. 1 to 2, in an embodiment of the present invention, when the rf receiving coil mounting bracket 1 includes a central plate 11, an upper plate 12, a lower plate 13, a front plate 14, a rear plate 15, a left plate 16, and a right plate 17, the first mounting groove, the second mounting groove, the third mounting groove, the fourth mounting groove, the fifth mounting groove, and the sixth mounting groove are respectively disposed in the left plate 16, the right plate 17, the upper plate 12, the lower plate 13, the front plate 14, and the rear plate 15.
When the magnetic resonance imaging device is used, the radio frequency receiving coil mounting support 1 is placed in a magnet of a 7.0T animal experiment magnetic resonance imaging system, the coil symmetric center point of the radio frequency receiving coil mounting support 1 is located at the center of the magnet by adjusting the positions of the fixing support 2 and the supporting support 3, and the left-right direction, the up-down direction and the front-back direction are coincided with the X axis, the Y axis and the Z axis of a magnetic field generated by the magnet. And then, each primary preamplifier is connected to a radio frequency signal receiving link, so that each channel of the spectrometer can receive measurement signals at different positions, the signal-to-noise ratio of the signals is high, and eddy current data analysis can be simultaneously carried out.
Specifically, the fixing support 2 is held by hand, the radio frequency receiving coil mounting support 1 and the supporting support 3 are placed into the radio frequency transmitting coil, the whole measuring device is firstly rotated along a plane perpendicular to the X direction and the Y direction, so that the whole measuring device is perpendicular to the plane in the X direction and the Y direction, then the position of the supporting support 3 is adjusted (if the supporting support 3 is a sector plate and the diameter of a circle where the supporting support 3 is located is the same as the inner diameter of the radio frequency transmitting coil, the position of the supporting support 3 does not need to be adjusted) so that the coil symmetric center point of the radio frequency receiving coil mounting support 1 is located at the center of the radio frequency transmitting coil, and then the amount estimating device is arranged in the radio frequency transmitting coil along the Z direction until the position mark point 24 and the corresponding position.
From mechanical structure, the utility model discloses a main structure carrier for 7.0T animal experiment magnetic resonance imaging system's eddy current measuring device includes the three, can constitute by plastics PC, the first part is radio frequency receiving coil installing support 1, about (X), about (Y) and front and back (Z) three direction to coil symmetric center point is the symmetric point, reserves printed circuit board mounting groove and coil mounting hole on the equidistance position, printed circuit board mounting groove and coil mounting hole pass through precision finishing, ensure that the mounted position is accurate. The size of the radio frequency receiving coil mounting bracket 1 is designed according to the inner aperture of the radio frequency transmitting coil, so that the size of the radio frequency receiving coil mounting bracket 1 is ensured to be matched with the inner aperture of the radio frequency transmitting coil, and the radio frequency receiving coil mounting bracket 1 can be ensured to be accurate in the left-right (X) and up-down (Y) directions after the radio frequency receiving coil mounting bracket 1 is placed into the radio frequency transmitting coil. The second part is a fixed support 2 which can be a circular plastic PC and is connected with the radio frequency receiving coil mounting support 1, the circular structure has high mechanical strength, the radio frequency receiving coil mounting support 1 can be supported to put in and take out a radio frequency transmitting coil, and meanwhile, an operator can conveniently hold the radio frequency transmitting coil to place and adjust the position. The position mark points 24 on the fixed support 2 can ensure that the position of the radio frequency receiving coil mounting support 1 in the front-back (Z) direction is accurate. The third part is a support bracket 3, which may be a fan-shaped plastic PC sheet, for supporting the entire device, the radius of the fan-shaped sheet being identical to the inner diameter of the radio frequency transmission coil, ensuring that the entire device is located in the imaging center in the circumferential direction.
From electric structure, the utility model discloses an eddy current measurement device for 7.0T animal experiment magnetic resonance imaging system mainly comprises six radio frequency receiving coil, and these six radio frequency receiving coil can all be solenoid structure, and the tuning part of coil comprises printed circuit board, and six radio frequency receiving coil's received signal is connected to one-level preamplifier respectively, through coil cable and joint output.
From FID signal acquisition, each radio frequency receiving coil is internally provided with a subminiature cylindrical water film 10 with the diameter of 2.5mm and the height of 3.5mm, the radio frequency receiving coil and the water film 10 have smaller volumes, coil tuning can achieve higher quality factors, and the FID acquisition signal has high signal-to-noise ratio through amplification of a primary preamplifier, and meanwhile, the small water film 10 can avoid errors caused by non-uniform magnetic field factors on measurement, so that the accuracy of eddy current measurement can be greatly improved. In addition, six radio frequency receiving coils gather the FID signal of six positions respectively, divide six passageways to send to the spectrometer receiving channel simultaneously, need not to put water film 10 again in whole measurement process to gather the FID signal of six positions simultaneously, shorten measuring time greatly.
The technical advantages of the utility model reside in that:
1. the accurate placement of the positions of the solenoid receiving coil and the water film is realized through the precisely processed radio frequency receiving coil mounting bracket.
2. Signals of six required positions are collected simultaneously, a water film does not need to be moved in the test process, and the measurement time is greatly shortened.
3. The radio frequency receiving coil adopts a solenoid structure, the coil can be tuned to a higher quality factor, and meanwhile, the signal-to-noise ratio of the acquired signal can be improved by enabling the acquired signal to pass through a primary preamplifier.
4. The influence of the nonuniformity of the magnetic field on the eddy current measurement can be reduced by using a smaller water film, and the measurement accuracy is improved.
The beneficial effects of the utility model mainly lie in:
1. the utility model discloses an eddy current measurement device for 7.0T animal experiment magnetic resonance imaging system includes 6 radio frequency receiving coil, places the water film in the radio frequency receiving coil, can receive the FID signal of 6 positions simultaneously, can satisfy the eddy current test to the accurate requirement of water film position and to the collection of FID signal.
2. The utility model discloses a radio frequency receiving coil installing support that is used for 7.0T animal experiment magnetic resonance imaging system to include according to the regional aperture design of formation of image of magnet, adopts the plastic material of easy processing, and complete processing reserves the mounted position of radio frequency coil circuit board, can realize the accurate positioning of radio frequency receiving coil and water film position, so can improve the accuracy of eddy current test greatly.
3. The utility model discloses a six radio frequency receiving coil that eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system includes are the solenoid structure, can accomplish small, and the tuned part of coil adopts the printed circuit board design simultaneously, can accomplish the tuning precision height, and the quality factor is high, consequently can increase substantially the SNR of signal collection.
4. The utility model discloses a vortex measuring device for 7.0T animal experiment magnetic resonance imaging system contains 6 diameter 2.5mm, high 3.5 mm's subminiature cylinder water film, and the water film is small, consequently can reduce the measuring error who brings because the magnetic field is inhomogeneous in the vortex measurement process, can improve vortex measurement's accuracy by a wide margin.
5. The utility model discloses a vortex measuring device for 7.0T animal experiment magnetic resonance imaging system contains 6 one-level preamplifier, can realize 6 passageway outputs, exports 6 receiving channel of spectrometer respectively, has realized 6 channel signal and has gathered simultaneously, and whole test procedure need not to remove the water film, has saved scan time greatly.
6. The utility model discloses an eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system contains radio frequency receiving coil installing support and fixed bolster, according to the regional aperture of formation of image and the design of magnet length of magnet, can be convenient put into the formation of image space and guarantee that the position is accurate with whole device through the setpoint of design.
Therefore, the utility model discloses a vortex measuring device for 7.0T animal experiment magnetic resonance imaging system designs uniquely, can gather X, Y, Z three directions simultaneously and carry out eddy current analysis totally 6 magnetic resonance signals of position, can accomplish in short time and gather and fit vortex distribution curve, and the sampling signal-to-noise ratio is high, and the structure is succinct, makes portably, and is with low costs.
To sum up, the utility model discloses an eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system measuring signal SNR is good, measures portably, quick, accurate, design benefit, and the structure is succinct, makes portably, and is with low costs, is suitable for extensive popularization and application.
Therefore, the purpose of the utility model is completely and effectively realized. The functional and structural principles of the present invention have been shown and described in the embodiments, and the embodiments may be modified without departing from the principles. Therefore, the present invention includes all modifications within the spirit and scope of the appended claims.
Claims (10)
1. The utility model provides an eddy current measurement device for 7.0T animal experiment magnetic resonance imaging system, its characterized in that, includes radio frequency receiving coil installing support, fixed bolster and support holder, first radio frequency receiving coil, second radio frequency receiving coil, third radio frequency receiving coil, fourth radio frequency receiving coil, fifth radio frequency receiving coil, sixth radio frequency receiving coil and 6 water films, wherein:
the fixing support is arranged on the supporting support, and the radio frequency receiving coil mounting support is arranged on the fixing support and is used for being placed in a magnet of a 7.0T animal experiment magnetic resonance imaging system when in use;
the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are all arranged on the radio frequency receiving coil mounting bracket, the radio frequency receiving coil mounting bracket is provided with a coil symmetric center point, the first radio frequency receiving coil and the second radio frequency receiving coil are arranged along the left-right direction and are arranged in point symmetry relative to the coil symmetric center point, the third radio frequency receiving coil and the fourth radio frequency receiving coil are arranged along the up-down direction and are arranged in point symmetry relative to the coil symmetric center point, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are arranged along the front-back direction and are arranged in point symmetry relative to the coil symmetric center point, and the distance between the first radio frequency receiving coil and the second radio frequency receiving coil, The distance between the third radio frequency receiving coil and the fourth radio frequency receiving coil is equal to the distance between the fifth radio frequency receiving coil and the sixth radio frequency receiving coil, and the 6 water films are respectively arranged in the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil.
2. The eddy current measuring apparatus for a 7.0T animal experiment magnetic resonance imaging system according to claim 1, wherein the rf receiver coil mounting bracket comprises a center plate, an upper plate, a lower plate, a front plate, a rear plate, a left plate, and a right plate, the center plate, the upper plate, the lower plate, the front plate, and the rear plate are all disposed along the front-rear direction, the coil center of symmetry is located at the center of the center plate, the upper plate and the lower plate are respectively disposed at the upper end and the lower end of the center plate, the front plate and the rear plate are respectively disposed at the front end and the rear end of the center plate, the left plate and the right plate are all disposed along the left-right direction and are respectively disposed at the left side and the right side of the center plate, the first rf receiver coil, the second rf receiver coil, the third rf receiver coil, and the rf receiver coil are respectively disposed at the left side and the right side of the center plate, The fourth radio frequency receiving coil, the fifth radio frequency receiving coil and the sixth radio frequency receiving coil are respectively arranged on the left plate, the right plate, the upper plate, the lower plate, the front plate and the rear plate.
3. The eddy current measurement apparatus for a 7.0T animal experiment magnetic resonance imaging system according to claim 1, wherein the radio frequency receiving coil mounting bracket is provided with a first mounting hole, a second mounting hole, a third mounting hole, a fourth mounting hole, a fifth mounting hole, and a sixth mounting hole, and the first radio frequency receiving coil, the second radio frequency receiving coil, the third radio frequency receiving coil, the fourth radio frequency receiving coil, the fifth radio frequency receiving coil, and the sixth radio frequency receiving coil are respectively provided in the first mounting hole, the second mounting hole, the third mounting hole, the fourth mounting hole, the fifth mounting hole, and the sixth mounting hole.
4. The eddy current measurement apparatus for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 1, wherein the first, second, third, fourth, fifth and sixth radio frequency receive coils are all solenoid receive coils.
5. The eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 1, wherein the fixing support is a circular tube, and the circular tube is disposed along the front-back direction.
6. The eddy current measurement apparatus for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 1, wherein the support bracket is a sector-shaped plate member, the sector-shaped plate member is disposed along the left-right direction, and a lower portion of the sector-shaped plate member is larger than an upper portion thereof.
7. An eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 6, wherein the sector plate member is in the same circle with the same diameter as the inner diameter of the magnet.
8. The eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 1, wherein the eddy current measuring device for a 7.0T animal experiment magnetic resonance imaging system further comprises position marking points disposed on the fixing bracket along the left-right direction for aligning with corresponding position marking points on the magnet to accurately position the front-back direction.
9. The eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system as claimed in claim 1, wherein the eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system further comprises a first stage preamplifier, a second stage preamplifier, a third stage preamplifier, a fourth stage preamplifier, a fifth stage preamplifier and a sixth stage preamplifier, wherein the first stage preamplifier, the second stage preamplifier, the third stage preamplifier, the fourth stage preamplifier, the fifth stage preamplifier and the sixth stage preamplifier are all mounted on the fixed bracket and respectively connected with the first RF receiving coil, the second RF receiving coil, the third RF receiving coil, the fourth RF receiving coil, The fifth radio frequency receive coil and the sixth radio frequency receive coil.
10. The eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system according to claim 1, wherein the eddy current measurement device for a 7.0T animal experiment magnetic resonance imaging system further comprises a first printed wiring board, a second printed wiring board, a third printed wiring board, a fourth printed wiring board, a fifth printed wiring board and a sixth printed wiring board, the first printed wiring board, the second printed wiring board, the third printed wiring board, the fourth printed wiring board, the fifth printed wiring board and the sixth printed wiring board are all disposed on the rf receiving coil mounting bracket, and the first rf receiving coil, the second rf receiving coil, the third rf receiving coil, the fourth rf receiving coil, the fifth rf receiving coil and the sixth rf receiving coil are respectively disposed on the first printed wiring board, the second rf receiving coil, the third rf receiving coil, the fourth rf receiving coil, the fifth rf receiving coil and the sixth rf receiving coil, The second printed wiring board, the third printed wiring board, the fourth printed wiring board, the fifth printed wiring board, and the sixth printed wiring board.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201920785001.XU CN210243815U (en) | 2019-05-28 | 2019-05-28 | Eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system |
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| CN201920785001.XU CN210243815U (en) | 2019-05-28 | 2019-05-28 | Eddy current measuring device for 7.0T animal experiment magnetic resonance imaging system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112462310A (en) * | 2020-10-16 | 2021-03-09 | 电子科技大学 | Device and method for detecting and compensating gradient eddy current based on inductance coil |
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2019
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112462310A (en) * | 2020-10-16 | 2021-03-09 | 电子科技大学 | Device and method for detecting and compensating gradient eddy current based on inductance coil |
| CN112462310B (en) * | 2020-10-16 | 2021-09-24 | 电子科技大学 | Device and method for detecting and compensating gradient eddy current based on inductance coil |
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