CN110703171B - Multi-core magnetic resonance system gas imaging quality testing die body - Google Patents
Multi-core magnetic resonance system gas imaging quality testing die body Download PDFInfo
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- CN110703171B CN110703171B CN201911095550.5A CN201911095550A CN110703171B CN 110703171 B CN110703171 B CN 110703171B CN 201911095550 A CN201911095550 A CN 201911095550A CN 110703171 B CN110703171 B CN 110703171B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/0023—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/58—Calibration of imaging systems, e.g. using test probes, Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material
Abstract
The invention discloses a gas imaging quality testing die body of a multi-core magnetic resonance system, which comprises a structural base body, wherein the structural base body is placed in an air bag, the air bag is provided with an air nozzle, a bracket supports and clamps the structural base body from the outside of the air bag, the structural base body is provided with a resolution testing grid and a geometric distortion testing through hole which penetrate through the upper surface and the lower surface of the structural base body, a two-dimensional layer thickness testing inclined slotted hole is formed in the structural base body, a notch of the two-dimensional layer thickness testing inclined slotted hole is positioned on the side surface of the structural base body, and a water solution sealing. The invention adopts hyperpolarized gas as imaging medium, which is closer to the actual condition of hyperpolarized gas imaging compared with a thermal polarized gas mold body; the gas in the mold is diffused rapidly, and the imaging signal is strong and stable; a complex vacuumizing device is not needed, and the air suction and inflation operations are simple and convenient; the coil can be effectively loaded by matching the load die body conveniently; multiple aspects of gas magnetic resonance image quality parameters can be obtained with one phantom.
Description
Technical Field
The invention belongs to the field of multi-nuclear magnetic resonance imaging, and particularly relates to a gas imaging quality test die body of a multi-nuclear magnetic resonance system.
Background
Hyperpolarized noble gas imaging is one direction in which multi-nuclear magnetic resonance imaging techniques have high clinical value and is currently moving to clinical applications.
In magnetic resonance imaging techniques, test phantoms are used to evaluate the imaging performance of a magnetic resonance system. A set of standardized test die bodies is arranged in the traditional water proton magnetic resonance imaging quality detection. As the hyperpolarized gas magnetic resonance image quality test standard does not exist at present, image quality detection items such as resolution, two-dimensional layer thickness, geometric distortion and the like can refer to a test mold body and a method in the conventional proton magnetic resonance detection standard. However, due to the characteristics of hyperpolarized gas magnetic resonance imaging, the special test die body can be distinguished from the water proton imaging test die body in the following points:
1. the imaging media are different. The water proton imaging test model body adopts water solution as an imaging medium. In the multi-nuclear magnetic resonance imaging technology, a magnetic resonance signal emitted by a non-hydrogen nucleus needs to be detected, and inert gas is required to be used as a signal source in a hyperpolarized gas magnetic resonance imaging test die body.
2. The packaging method is different. Different from a water proton imaging test die body which simply adopts a sealed container to contain solution, the gas imaging test die body needs to be provided with a container and a mechanism suitable for evacuation, filling and sealing of normal pressure or high pressure gas.
3. Signal strength and stability varied. The magnetic resonance signal of a hot polarized gas phantom is weak compared to an aqueous phantom, and the signal of a hyperpolarized gas phantom decays over time.
4. The coil loading requirements are different. The aqueous phantom itself may be used as a load for the imaging coil, but the gas phantom requires additional loading for imaging testing, particularly when the transmit coil fill rate is high.
The existing inert gas magnetic resonance test die body uses hot polarized gas as a signal source. But when a plurality of image parameter tests are carried out, the hyperpolarized gas is more suitable. The reasons are the following:
1. the use of hyperpolarized gases to test the phantom more closely approximates true evaluation of hyperpolarized gas magnetic resonance imaging quality.
2. The signal-to-noise ratio of the image obtained with the hot polarized gas is low, a clear image of the test structure cannot be obtained, and the signal of the hyperpolarized gas is much stronger.
3. In order to enhance the hot-polarized gas signal, pressurization is often required to increase the gas density, which increases the compressive strength and bulk weight of the die body cavity and may present a safety hazard. And the hyperpolarized gas can be used to achieve atmospheric imaging.
Due to the specificity of gas magnetic resonance, a dedicated test phantom needs to establish a similar gas structure or environment, and several problems need to be solved: selecting a proper gas testing structure and a proper gas container form and structure; in order to obtain high-definition and high signal-to-noise ratio imaging of the fine structure on the detection die body as much as possible, measures are required to avoid rapid attenuation of the hyperpolarized gas signal; air discharge and hyperpolarized gas filling can be conveniently and rapidly carried out; the test structure on the test die body can be conveniently and accurately selected and positioned before the test image is obtained; in addition, due to the particularity of the implementation of the gas magnetic resonance hardware, effective loading of the coil needs to be guaranteed in the testing die body. At present, a hyperpolarized gas magnetic resonance image quality testing phantom which can effectively meet the requirement is not available.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a gas imaging quality testing die body of a multi-core magnetic resonance system, which is used for detecting image quality parameters such as resolution, geometric distortion, two-dimensional layer thickness and the like of hyperpolarized gas imaging and has the characteristics of strong image signal, good repeatability and high gas utilization rate.
The utility model provides a gaseous imaging quality test die body of multinuclear magnetic resonance system, includes the structural matrix, the structural matrix is placed inside the gas bag, be provided with the air cock on the gas bag, the bracket supports centre gripping structural matrix from the gas bag outside, be provided with resolution test grid and the geometric distortion test through-hole of the upper and lower surface that link up the structural matrix body on the structural matrix, be provided with the oblique slotted hole of two-dimentional bed thickness test in the structural matrix, the notch of the oblique slotted hole of two-dimentional bed thickness test is located the side surface of structural matrix body, still be provided with the sealed chamber of aqueous.
The upper surface of the structure base body is provided with the air guide groove communicated with the upper surface opening of the resolution testing grid, the lower surface of the structure base body is provided with the air guide groove communicated with the lower surface opening of the resolution testing grid, the air guide pipe hole communicated with the resolution testing grid and the two-dimensional layer thickness testing inclined groove hole is formed in the structure base body, and the air guide pipe hole is communicated with the outside of the structure base body.
The resolution test grid is arranged in the middle of the structural matrix, and the geometric distortion test through holes are arranged in the middle and at the edge of the structural matrix.
The two-dimensional layer thickness test inclined slot hole is arranged in the structure base body at a position which is not intersected with the resolution test grid and the geometric distortion test through hole, a set angle is formed between the two-dimensional layer thickness test inclined slot hole and the horizontal plane, and the notch of the two-dimensional layer thickness test inclined slot hole is positioned on the side surface of the structure die body.
The thickness of the aqueous solution sealed cavity as described above corresponds to the thickness of the structural substrate.
Compared with the prior art, the invention has the following beneficial effects:
the hyperpolarized gas is used as an imaging medium, and compared with a hot polarized gas mold body, the hyperpolarized gas mold body is closer to the actual situation of hyperpolarized gas imaging; the gas in the mold is diffused rapidly, and the imaging signal is strong and stable; a complex vacuumizing device is not needed, and the air suction and inflation operations are simple and convenient; the coil can be effectively loaded by matching the load die body conveniently; multiple aspects of gas magnetic resonance image quality parameters can be obtained with one phantom.
Drawings
Fig. 1 is a schematic cross-sectional structure of the present invention.
Fig. 2 is a schematic structural view of a structural matrix.
In the figure: 1-a structural matrix; 2-aqueous solution sealing cavity; 3-two-dimensional layer thickness test inclined slotted holes; 4-resolution test grid; 5-geometric distortion test through holes; 6-air guide groove; 7-an inflatable bag; 8-air tap; 9-a bracket; 10-air guide duct hole.
Figure 3 is a schematic diagram of a mating structure of a human lung imaging coil and a human lung loading phantom.
In the figure: 11-human lung imaging coil, 12-human lung load die body.
Detailed Description
The present invention will be described in further detail with reference to examples for the purpose of facilitating understanding and practice of the invention by those of ordinary skill in the art, and it is to be understood that the present invention has been described in the illustrative embodiments and is not to be construed as limited thereto.
A gas imaging quality testing die body of a multi-core magnetic resonance system comprises a structural matrix 1, an inflatable bag 7 and a bracket 9.
The structural matrix 1 is placed inside the airbag 7. The gas-filled bag 7 is used to fill with a hyperpolarized gas and to place the structural substrate 1 in a hyperpolarized gas environment. The structural substrate 1 is held from outside the airbag 7 using a bracket 9 and is inflated underneath the structural substrate 1. In order to ensure good circulation of the super-saturated gas inside and outside the resolution test grids 4 and the geometric distortion test through holes 5 in the structural matrix 1, the openings of the resolution test grids 4 and the geometric distortion test through holes 5 on the upper and lower surfaces of the structural matrix 1 are not covered by the support positions of the bracket 9 supporting the structural matrix 1.
The structural substrate 1 is in the shape of a thick plate, in this example a circular plate, on which a resolution test grid 4, a geometric distortion test through hole 5, and a two-dimensional layer thickness test inclined slot hole 3 are arranged. The shapes of the resolution test grid 4, the geometric distortion test through hole 5 and the two-dimensional layer thickness test inclined slot 3 can refer to the relevant content of the image quality parameter determination industry standard of the medical imaging magnetic resonance equipment suitable for proton MRI. Resolution test grid 4 sets up in the plectane middle part of structure base member 1, and geometric distortion test through-hole 5 sets up in the plectane central authorities of structure base member 1 and is close to the circumference border position, and resolution test grid 4, geometric distortion test through-hole 5 take the inside form of hollowing out of structure base member 1 to realize, and resolution test grid 4, geometric distortion test through-hole 5 all link up the upper and lower surface of structure die body 1. The two-dimensional layer thickness test inclined slotted hole 3 is arranged at a position, which is not intersected with the resolution test grid 4 and the geometric distortion test through hole 5, in the structure base body 1, the two-dimensional layer thickness test inclined slotted hole 3 forms a set angle with the horizontal plane, the notch of the two-dimensional layer thickness test inclined slotted hole 3 is positioned on the side surface of the structure die body, the two-dimensional layer thickness test inclined slotted hole 3 is also realized in a mode of hollowing out the inside of the structure base body 1, and the orifice of the two-dimensional layer thickness test inclined slotted hole 3 is positioned on. In order to facilitate air extraction and hyperpolarization gas filling of the inner cavity, the upper surface of the structural substrate 1 is provided with an upper surface open-ended air guide groove 6 communicated with the resolution testing grid 4, the lower surface of the structural substrate 1 is provided with a lower surface open-ended air guide groove 6 communicated with the resolution testing grid 4, the structural substrate 1 is internally provided with an air guide pipe hole 10 communicated with the resolution testing grid 4 and the two-dimensional layer thickness testing inclined slotted hole 3, and the orifice of the air guide pipe hole 10 is positioned on the outer surface of the structural substrate 1 and is communicated with the outside.
The air guide groove 6 is a narrow concave groove structure on the upper surface and the lower surface of the structural substrate 1 and is used for providing an air flow channel after the inflatable bag is tightly attached to the surface of the structural substrate 1 in the air exhaust stage.
In order to improve the utilization rate of gas and avoid puncturing the air bag 7 during air extraction, the surface of the structural matrix 1 is flat and has no sharp protrusions.
Besides the gas test structure, the structural substrate 1 is provided with an aqueous solution sealed cavity 2 for positioning. The shape and the position of the water solution sealed cavity 2 are arranged, so that the layer selection and the positioning of the structural matrix 1 can be conveniently realized through proton scanning. A plurality of individual aqueous solution sealed cavities 2 may be arranged in a uniform distribution at the edge of the structural substrate 1. The water solution sealing cavity 2 is cylindrical, the diameter is preferably 1cm, the height is equal to the thickness of the structural matrix, and the two ends of the water solution sealing cavity 2 are sealed after water solution is filled in the water solution sealing cavity. Or, a circular through hole or a circular hole groove is formed in the structure base body 1 except for the resolution testing grid 4, the geometric distortion testing through hole 5 and the two-dimensional layer thickness testing inclined groove hole 3, and aqueous solution is poured and sealed at two ends, so that the aqueous solution sealing cavity 2 penetrates through the structure base body 1 and forms a whole.
Considering that the heights of the resolution testing grid 4, the geometric distortion testing through hole 5 and the two-dimensional layer thickness testing inclined slot 3 should be not less than the layer thickness setting during the image quality test, the thickness of the structural substrate 1 is preferably 3-4 cm.
The material of the structural matrix 1 is a rigid non-magnetic material having little influence on the relaxation of the hyperpolarized gas, and is preferably teflon, nylon or abs.
The air bag 7 is used for filling and sealing the hyperpolarized gas, and an air nozzle 8 with a switch is arranged on the air bag 7. The airbag 7 is arranged outside the structural substrate 1 and is shaped to appropriately wrap the structural substrate 1. In order to ensure that the structural matrix 1 is immersed in a proper amount of hyperpolarized gas, the volume of the inflated airbag 7 is preferably 1.1-1.5 times of the volume of the structural matrix 1. The material of the air bag 7 is a flexible non-magnetic material with small influence on the relaxation of the hyperpolarized gas, and preferably Tedela and Teflon.
The comprehensive die body for the hyperpolarized gas imaging test of the multi-core magnetic resonance system can be used for testing various hyperpolarized gas imaging coils. The present example illustrates the use of a human lung imaging coil 11 and a human lung load phantom 12.
During imaging test, firstly, the human lung imaging coil 11 is sleeved outside the human lung load phantom 12 and is placed on the magnetic resonance scanning bed, and then the comprehensive phantom for hyperpolarized gas imaging test of the multi-nuclear magnetic resonance system is placed in the center of the cavity inside the human lung load phantom 12, as shown in fig. 3. The human lung load die body 12 is an elliptical ring cylinder or a long circular ring cylinder, the cross section of the human lung load die body is an elliptical ring or a long circular ring, electrolyte liquid is filled between the inner ring wall and the outer ring wall of the human lung load die body 12, and the components of the electrolyte liquid are water, NaCl and PVP. NaCl can influence the matching state of the coil, and PVP can influence the resonance frequency of the coil. Typically, the concentration of NaCl is 0.4% and the concentration of PVP (polyvinylpyrrolidone) is 1.2%. The bed is fed into the center of the magnet of the magnetic resonance imager. The switch of the air tap 8 of the air bag 7 is opened, and the switch of the air tap 8 is closed after the air in the air bag 7 is pumped out by using a manual air pump. The scan sequence and positioning selection are prepared. The switch of the air tap 8 is opened, the hyperpolarized gas is filled into the airbag 7, and the switch is closed after the airbag 7 is slightly inflated. And operating an imaging scanning sequence to obtain a hyperpolarized gas magnetic resonance image of the resolution testing grid 4, the geometric distortion testing through hole 5 and the two-dimensional layer thickness testing inclined slot 3 on the structural substrate 1.
It should be noted that the specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.
Claims (4)
1. A multi-core magnetic resonance system gas imaging quality test die body comprises a structure base body (1) and is characterized in that the structure base body (1) is placed inside an air bag (7), an air nozzle (8) is arranged on the air bag (7), a bracket (9) supports the clamping structure base body (1) from the outside of the air bag (7) and fills the lower part of the structure base body (1), a resolution test grid (4) and a geometric distortion test through hole (5) which penetrate through the upper surface and the lower surface of the structure die body (1) are arranged on the structure base body (1), a two-dimensional layer thickness test inclined slotted hole (3) is arranged in the structure base body (1), a notch of the two-dimensional layer thickness test inclined slotted hole (3) is positioned on the side surface of the structure die body (1), a water solution sealing cavity (2) is also arranged on the structure,
the upper surface of the structural base body (1) is provided with an air guide groove (6) communicated with an upper surface opening of the resolution testing grid (4), the lower surface of the structural base body (1) is provided with an air guide groove (6) communicated with a lower surface opening of the resolution testing grid (4), an air guide pipe hole (10) provided with the communicated resolution testing grid (4) and a two-dimensional layer thickness testing inclined groove hole (3) is formed in the structural base body (1), and the air guide pipe hole (10) is communicated with the outside of the structural base body (1)
The support position of the bracket (9) for supporting the structural matrix (1) does not cover the openings of the resolution testing grid (4) and the geometric distortion testing through hole (5) on the upper and lower surfaces of the structural matrix (1),
the volume of the inflated air bag (7) is 1.1-1.5 times of the volume of the structural matrix (1), and the air bag (7) is made of tedlar or teflon.
2. The gas imaging quality test phantom of the multi-nuclear magnetic resonance system according to claim 1, wherein the resolution test grid (4) is disposed in the middle of the structural substrate (1), and the geometric distortion test through holes (5) are disposed in the middle and at the edge of the structural substrate (1).
3. The gas imaging quality test die body of the multi-core magnetic resonance system according to claim 2, wherein the two-dimensional layer thickness test inclined slot (3) is arranged in the structure base body (1) at a position which is not intersected with the resolution test grid (4) and the geometric distortion test through hole (5), the two-dimensional layer thickness test inclined slot (3) forms a set angle with the horizontal plane, and the notch of the two-dimensional layer thickness test inclined slot (3) is positioned on the side surface of the structure die body (1).
4. The gas imaging quality test phantom of a multi-nuclear magnetic resonance system according to claim 3, characterized in that the thickness of the aqueous solution sealed cavity (2) is consistent with the thickness of the structural matrix (1).
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| US4682112A (en) * | 1984-10-10 | 1987-07-21 | Elscint Ltd. | NMR antenna and method for designing the same |
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| CN203591259U (en) * | 2013-09-24 | 2014-05-14 | 西门子(深圳)磁共振有限公司 | Die body of magnetic resonance imaging system |
| CN105866275A (en) * | 2016-04-05 | 2016-08-17 | 济宁神农画圆生态系统模式推广有限公司 | Method and device for quantitative analysis on nitrogen-oxygen absorption capacity of nitrogen-fixing bacteria in sealed container |
| CN207675917U (en) * | 2018-01-24 | 2018-07-31 | 浙江优纳特科学仪器有限公司 | A kind of Magnetic resonance imaging quality testing die body |
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2019
- 2019-11-11 CN CN201911095550.5A patent/CN110703171B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4682112A (en) * | 1984-10-10 | 1987-07-21 | Elscint Ltd. | NMR antenna and method for designing the same |
| CN1137229A (en) * | 1993-11-24 | 1996-12-04 | 麦格纳·莱伯公司 | Inflatable magnetic resonance imaging sensing coil device |
| CN1803091A (en) * | 2005-11-24 | 2006-07-19 | 上海交通大学 | Performance testing device for superpolarized inertia gas nuclear magnetic resonance system |
| CN101870392A (en) * | 2009-04-22 | 2010-10-27 | 天津市医学堂科技有限公司 | Inflatable filling bag capable of being repeatedly used |
| CN203591259U (en) * | 2013-09-24 | 2014-05-14 | 西门子(深圳)磁共振有限公司 | Die body of magnetic resonance imaging system |
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