High-field magnetic resonance imaging system with self-shielding function

Abstract

The invention discloses a high-field magnetic resonance imaging system with a self-shielding function. In the system, a self-shielding cover comprises a front shielding window located at a scanning end and a rear shielding window located at a server end, the front shielding window and the rear shielding window are respectively connected with the end faces of a front sealing head and a rear sealing head of a superconducting magnet, and a complete radio frequency closed space is formed by the front shielding window and the rear shielding window together with a superconducting magnet vacuum cavity inner cylinder in the superconducting magnet; a gradient line and a temperature control line of the gradient coil at the server side are connected with the magnetic resonance spectrometer through a gradient filter; and a radio frequency line of the radio frequency coil at the scanning end is switched through a vacuum corrugated pipe connected with the front shielding window and is sequentially connected to a radio frequency front end, a radio frequency filter and a magnetic resonance spectrometer. A magnetic resonance shielding room does not need to be built, and the cost of a magnetic resonance system is greatly saved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-field magnetic resonance imaging, and in particular relates to a high-field magnetic resonance imaging system with a self-shielding function. Background Art

[0002] Existing MRI systems need to be installed in a MRI shielded room, which requires the construction of an independent RF shielded room to isolate external signal noise and eliminate imaging artifacts and distortion caused by noise. Building such a MRI shielded room undoubtedly increases the cost of the equipment, as well as the complexity and installation cycle of the equipment. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a high-field magnetic resonance imaging system with self-shielding function, which does not require the construction of a magnetic resonance shielding room and can achieve the same imaging effect as a conventional magnetic resonance system with a shielding room.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A high-field magnetic resonance imaging system with self-shielding function, the system comprising: a superconducting magnet, a gradient coil, a radio frequency coil, a magnetic resonance spectrometer, a self-shielding cover, a gradient filter, a radio frequency front end, a radio frequency filter, and a vacuum bellows, wherein:

[0006] The self-shielding cover comprises a front shielding window located at the scanning end and a rear shielding window located at the service end, wherein the front shielding window and the rear shielding window are respectively connected to the front and rear end surfaces of the superconducting magnet, and together with the superconducting magnet vacuum chamber inner cylinder in the superconducting magnet, form a complete radio frequency closed space;

[0007] The gradient line and the temperature control line of the gradient coil at the service end are connected to the magnetic resonance spectrometer through a gradient filter;

[0008] The radio frequency line of the radio frequency coil at the scanning end is switched through a vacuum bellows connected to the front shielding window and is connected to the radio frequency front end, the radio frequency filter and the magnetic resonance spectrometer in sequence.

[0009] Furthermore, the front shielding window and the rear shielding window both include an openable and closable transparent observation window, and the transparent observation window includes transparent glass that can prevent radio frequency signal radiation from penetrating.

[0010] Furthermore, the transparent observation window is connected to the observation window frames located at the front shielding window and the rear shielding window through a retaining spring.

[0011] Furthermore, the transparent glass is glass containing a copper wire grid.

[0012] Furthermore, the superconducting magnet is used to provide a highly uniform background magnetic field; and the gradient coil is used to generate a spatially positioned gradient magnetic field.

[0013] Furthermore, the gradient filter is used to filter the signal noise generated by the external power cables of the gradient coil. The gradient filter has an independent mounting plane and is installed below the rear shielding window of the service end through threads.

[0014] Furthermore, the transmitting and receiving cables of the RF coil are connected to the RF front end through a vacuum bellows for transmitting and receiving RF excitation signals. The RF front end is used to amplify and convert the RF signals, and is connected to the magnetic resonance spectrometer and RF power amplifier of the magnetic resonance control cabinet after passing through the RF filter.

[0015] Furthermore, the computer and its software are used to control the magnetic resonance spectrometer, control the transmission and reception of radio frequency signals and gradient pulse signals, obtain magnetic resonance imaging signals, and convert them into magnetic resonance image information after post-processing.

[0016] Furthermore, the gradient cable of the gradient coil is connected to the terminal of the gradient filter through the internal gradient plate, and the external gradient cable passing through the shielding cover is connected to the external terminal and fixed on the external gradient plate, and then connected to the magnetic resonance spectrometer; wherein the internal gradient plate and the external gradient plate are both fixed on the cross section of the magnet vacuum tank.

[0017] On the other hand, the present invention also provides a high-field magnetic resonance imaging system with self-shielding function, the system comprising: a superconducting magnet, a gradient coil, a radio frequency coil, a magnetic resonance spectrometer, a self-shielding cover, a radio frequency front end, a radio frequency filter, a vacuum bellows, and a gradient coil copper skin, wherein:

[0018] The copper skin of the gradient coil is located on the inner wall of the gradient coil;

[0019] The self-shielding cover comprises a front shielding window located at the scanning end and a rear shielding window located at the service end, wherein the front shielding window and the rear shielding window are respectively connected to the front and rear end surfaces of the gradient coil copper sheet to form a complete radio frequency closed space;

[0020] The gradient line and temperature control line of the gradient coil at the service end are directly connected to the magnetic resonance spectrometer;

[0021] The radio frequency line of the radio frequency coil at the scanning end is switched through a vacuum bellows connected to the front shielding window and is connected to the radio frequency front end, the radio frequency filter and the magnetic resonance spectrometer in sequence.

[0022] The beneficial effects of the present invention are:

[0023] The present invention does not require the construction of an MRI shielding room, and the proposed self-shielding system can completely replace the MRI shielding room, greatly saving the cost of the MRI system and shortening the installation time of the MRI equipment. Since the shielding room is replaced, the site planning of the MRI equipment becomes simpler, and all equipment can be placed in one room without the need to divide the scanning room, equipment room and operation room.

[0024] It lowers the threshold for using magnetic resonance imaging systems (especially high-field scientific research magnetic resonance systems) and shortens the equipment installation cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural block diagram of a high-field magnetic resonance imaging system with a self-shielding function according to the present invention;

[0026] Figure 2 It is a side view of the high-field magnetic resonance imaging system with the front and rear shielding windows closed;

[0027] Figure 3 It is a front view of the high-field magnetic resonance imaging system with the front and rear shielding windows closed;

[0028] Figure 4 It is a rear view of the high-field magnetic resonance imaging system with the front and rear shielding windows closed;

[0029] Figure 5 It is a side view of the high-field magnetic resonance imaging system with the front and rear shielding windows opened;

[0030] Figure 6 It is a front view of the high-field magnetic resonance imaging system with the front and rear shielding windows opened;

[0031] Figure 7 This is a rear view of the high-field magnetic resonance imaging system with the front and rear shielding windows opened;

[0032] Figure 8 This is the overall structure diagram with the front and rear shielding windows opened;

[0033] Fig. 9 It is a schematic diagram of the connection structure of the retaining spring at the observation window;

[0034] Fig.10 It is a partial enlarged schematic diagram of the connection structure of the clip at the observation window;

[0035] Fig.11 Schematic diagram of shielding window structure;

[0036] Fig.12 is a schematic diagram of the gradient plate structure;

[0037] Fig.13 This is another structural block diagram of a high-field magnetic resonance imaging system with self-shielding function according to the present invention.

[0038] Reference numerals:

[0039] 1-superconducting magnet, 2-gradient coil, 3-radio frequency coil, 4-magnetic resonance spectrometer, 5-self-shielding cover, 51-front shielding window, 52-rear shielding window, 6-gradient filter, 7-radio frequency front end, 8-radio frequency filter, 9-vacuum bellows, 10-superconducting magnet vacuum chamber inner cylinder, 11-circlip, 12-copper wire grid, 13-internal gradient plate, 14-external gradient plate, 15-gradient coil copper skin. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] like Figure 1 As shown, it is a structural block diagram of a high-field magnetic resonance imaging system with a self-shielding function of the present invention, comprising: a superconducting magnet 1, a gradient coil 2, a radio frequency coil 3, a magnetic resonance spectrometer 4, a self-shielding cover 5, a gradient filter 6, a radio frequency front end 7, a radio frequency filter 8, and a vacuum bellows 9.

[0042] The self-shielding cover 5 is divided into a scanning end self-shielding cover, i.e., a front shielding window 51, and a service end self-shielding cover, i.e., a rear shielding window 52. The self-shielding cover 5 has the same characteristic of being connected to the front and rear end faces of the superconducting magnet 1 to form a complete closed space. Due to the close connection between the self-shielding cover 5 and the end face of the superconducting magnet 1, together with the superconducting magnet vacuum chamber inner cylinder 10 in the superconducting magnet 1, a complete RF closed space can be formed. Figure 2 , Figure 3 , Figure 4 The side, front and back views of the high-field MRI system with the front and rear shielding windows closed are given respectively. Figure 5 , Figure 6 , Figure 7 The side, front and rear views of the high-field MRI system with the front and rear shielding windows open are given respectively. Figure 8 The self-shielding cover 5 is designed with a transparent observation window that can be opened and closed. The observation window is equipped with transparent glass that can prevent radio frequency signal radiation from penetrating and can be opened and closed as needed. Figure 9-10 As shown, a spring 11 is used as a sealing measure for opening and closing the observation window and the observation window frame. Fig.11 As shown, the observation window is made of glass containing a copper wire grid 12. In addition to being able to observe the animals in the scanning cavity, this glass can also maintain the radio frequency sealing effect.

[0043] The superconducting magnet 1 is suitable for high-field animal magnetic resonance imaging systems, usually with a magnetic field strength of 7 Tesla, and is used to provide a highly uniform background magnetic field. The scanning area is formed within a 65mm spherical domain (DSV) at the center of the superconducting magnet ISO.

[0044] The gradient coil 2 generates a spatially localized gradient magnetic field. The gradient line and the temperature control line at the service end are switched through a gradient filter 6 installed at the service end and then connected to the magnetic resonance spectrometer 4 .

[0045] The RF line of the RF coil 3 at the scanning end is connected through a vacuum bellows 9 connected to the front shielding window 51 of the scanning end, and is connected to the RF front end 7 and the RF filter 8, and then connected to the magnetic resonance spectrometer 4 via a RF cable.

[0046] The gradient filter 6 is used to filter the signal noise generated by the external powered cables of the gradient coil 2, such as the gradient cables, the gradient coil temperature sensor cables, the gradient coil active shimming coil cables, etc. The gradient filter 6 has an independent mounting plane and is threadedly mounted below the rear shielding window 52 of the service end.

[0047] The transmitting and receiving cables of the RF coil 3 are connected to the RF front end 7 through a vacuum bellows 9 for transmitting and receiving RF excitation signals. The RF front end 7 can amplify and convert RF signals, and after passing through the RF filter 8, it is connected to the magnetic resonance spectrometer 4 and the RF power amplifier of the magnetic resonance control cabinet.

[0048] The power cables and signal cables of the gradient coil 2 and the RF coil 3 are connected to the magnetic resonance spectrometer 4, gradient power amplifier, RF power amplifier and other components on the magnetic resonance control cabinet. The magnetic resonance spectrometer 4 is controlled by a computer and its software, thereby controlling the RF signal transmission and reception and the gradient pulse signal, and finally obtaining the magnetic resonance imaging signal, which is converted into magnetic resonance image information after post-processing.

[0049] like Fig.12 As shown, the gradient cable needs to pass through the self-shielding cover 5 to connect with the external magnetic resonance spectrometer 4, and complete the spatial positioning by exciting the gradient coil 2, so as to form a slice image in any direction. Specifically, the gradient cable is connected to the terminal of the gradient filter 8 through an internal gradient plate 13, and the external gradient cable passing through the self-shielding cover 5 is connected to the external terminal and fixed on the external gradient plate 14, and then connected to the magnetic resonance spectrometer 4. Both the internal gradient plate 13 and the external gradient plate 14 need to be fixed on the cross section of the magnet vacuum tank by screws. This ensures the reliability of the gradient cable working under the action of strong current electromagnetic force.

[0050] like Fig.13 As shown, another embodiment of a high-field magnetic resonance imaging system with a self-shielding function of the present invention comprises: a superconducting magnet 1, a gradient coil 2, a radio frequency coil 3, a magnetic resonance spectrometer 4, a self-shielding cover 5, a radio frequency front end 7, a radio frequency filter 8, a vacuum bellows 9, and a gradient coil copper skin 15. That is, the gradient filter 6 is no longer used here.

[0051] Since there is a gradient coil copper sheet 15 on the inner wall of the gradient coil 2 to suppress RF eddy currents, the self-shielding cover 5 is connected to the gradient coil copper sheet 15 to form a complete RF closed space. With this solution, the gradient wire and temperature control wire of the gradient coil 2 can be directly connected to the magnetic resonance spectrometer 4 without the need for switching through the gradient filter 6, because they are now completely isolated from the internal imaging area. The other cable connection methods are similar to Figure 1 The embodiments shown are connected in the same manner.

[0052] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-field magnetic resonance imaging system with self-shielding function, characterized in that: The system includes: a superconducting magnet, a gradient coil, a radio frequency coil, a magnetic resonance spectrometer, a self-shielding cover, a gradient filter, a radio frequency front end, a radio frequency filter, and a vacuum bellows, wherein: The self-shielding cover comprises a front shielding window located at the scanning end and a rear shielding window located at the service end, wherein the front shielding window and the rear shielding window are respectively connected to the front and rear end surfaces of the superconducting magnet, and together with the superconducting magnet vacuum chamber inner cylinder in the superconducting magnet, form a complete radio frequency closed space; The gradient line and the temperature control line of the gradient coil at the service end are connected to the magnetic resonance spectrometer through a gradient filter; The radio frequency line of the radio frequency coil at the scanning end is switched through a vacuum bellows connected to the front shielding window and is connected to the radio frequency front end, the radio frequency filter and the magnetic resonance spectrometer in sequence.

2. A high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The front shielding window and the rear shielding window both include an openable and closable transparent observation window, and the transparent observation window includes transparent glass that can prevent radio frequency signal radiation from penetrating.

3. A high-field magnetic resonance imaging system with self-shielding function according to claim 2, characterized in that: The transparent observation window is connected to the observation window frame located at the front shielding window and the rear shielding window through a clamping spring.

4. A high-field magnetic resonance imaging system with self-shielding function according to claim 2, characterized in that: The transparent glass is glass containing a copper wire grid.

5. A high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The superconducting magnet is used to provide a highly uniform background magnetic field; the gradient coil is used to generate a spatially positioned gradient magnetic field.

6. A high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The gradient filter is used to filter the signal noise generated by the external power cable of the gradient coil. The gradient filter has an independent mounting plane and is installed below the rear shielding window of the service end through threads.

7. A high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The transmitting and receiving cables of the RF coil are connected to the RF front end through a vacuum bellows for transmitting and receiving RF excitation signals. The RF front end is used to amplify and convert RF signals, and is connected to the magnetic resonance spectrometer and RF power amplifier of the magnetic resonance control cabinet after passing through the RF filter.

8. The high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The magnetic resonance spectrometer is controlled by a computer and its software, which controls the transmission and reception of radio frequency signals and gradient pulse signals, obtains magnetic resonance imaging signals, and converts them into magnetic resonance image information after post-processing.

9. The high-field magnetic resonance imaging system with self-shielding function according to claim 1, characterized in that: The gradient cable of the gradient coil is connected to the terminal of the gradient filter through the internal gradient plate, and the external gradient cable passing through the shielding cover is connected to the external terminal and fixed on the external gradient plate, and then connected to the magnetic resonance spectrometer; wherein the internal gradient plate and the external gradient plate are both fixed on the cross section of the magnet vacuum tank.

10. A high-field magnetic resonance imaging system with self-shielding function, characterized in that: The system includes: a superconducting magnet, a gradient coil, a radio frequency coil, a magnetic resonance spectrometer, a self-shielding cover, a radio frequency front end, a radio frequency filter, a vacuum bellows, and a gradient coil copper skin, wherein: The copper skin of the gradient coil is located on the inner wall of the gradient coil; The self-shielding cover comprises a front shielding window located at the scanning end and a rear shielding window located at the service end, wherein the front shielding window and the rear shielding window are respectively connected to the front and rear end surfaces of the gradient coil copper sheet to form a complete radio frequency closed space; The gradient line and temperature control line of the gradient coil at the service end are directly connected to the magnetic resonance spectrometer; The radio frequency line of the radio frequency coil at the scanning end is switched through a vacuum bellows connected to the front shielding window and is connected to the radio frequency front end, the radio frequency filter and the magnetic resonance spectrometer in sequence.

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