CN113504494B - Four-end ring birdcage radio frequency coil system supporting three-nuclide imaging - Google Patents

Four-end ring birdcage radio frequency coil system supporting three-nuclide imaging Download PDF

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CN113504494B
CN113504494B CN202110837831.4A CN202110837831A CN113504494B CN 113504494 B CN113504494 B CN 113504494B CN 202110837831 A CN202110837831 A CN 202110837831A CN 113504494 B CN113504494 B CN 113504494B
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end ring
variable capacitor
wire
capacitor
electrically connected
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CN113504494A (en
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李烨
李楠
杜凤
罗超
陈巧燕
刘新
郑海荣
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Shenzhen Institute of Advanced Technology of CAS
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Shenzhen Institute of Advanced Technology of CAS
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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
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
    • G01R33/34046—Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils
    • G01R33/34076—Birdcage coils

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  • General Physics & Mathematics (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)

Abstract

The invention provides a four-end ring birdcage radio frequency coil system supporting three nuclide imaging, which comprises: the first end ring, the second end ring, the third end ring and the fourth end ring are arranged in a common central shaft mode, the second end ring is located between the first end ring and the third end ring, and the third end ring is located between the second end ring and the fourth end ring; at least one of the first end ring, the second end ring, the third end ring and the fourth end ring is provided with an excitation port; a plurality of first conductive lines, a plurality of second conductive lines, and a plurality of third conductive lines, all parallel to the central axis; the first conducting wire is connected between the first end ring and the second end ring, the second conducting wire is connected between the second end ring and the third end ring, and the third conducting wire is connected between the third end ring and the fourth end ring; and the double-harmonic circuit is electrically connected with the excitation port and is used for realizing the resonant frequencies of the two nuclides. The invention realizes the resonant frequencies of three different nuclides at the same time, and the mutual frequencies show good electromagnetic isolation performance.

Description

Four-end ring birdcage radio frequency coil system supporting three-nuclide imaging
Technical Field
The invention relates to a nuclear magnetic resonance technology, in particular to a four-end ring birdcage radio frequency coil system supporting three-nuclide imaging.
Background
Achieving high quality imaging of biological endogenous weak signals faces a number of significant technical challenges. Compared with the traditional hydrogen proton MRI, the weak nuclide generally has a lower gyromagnetic ratio and a lower spatial resolution due to the lower content of the weak nuclide in the body and the image of the physical property of the weak nuclide, so that the magnetic field accurate excitation aiming at the biological signal of a specific frequency point and the high-sensitivity detection method and the multi-nuclear receiving coil of the magnetic resonance signal become important research points. In a multi-tuned coil system, the coils are, 1 the physical proximity of H and the aprotic elements results in strong coupling between the elements, severely degrading the coil sensitivity, which leads to longer acquisition times and increased inhomogeneity of the Radio Frequency (RF) field in order to improve the signal-to-noise ratio (SNR) and resolution. While an effective multi-nuclear radio frequency coil will help overcome the RF field inhomogeneity and SA low NR.
Disclosure of Invention
The embodiment of the invention provides a four-end ring birdcage radio frequency coil system supporting three nuclide imaging, so that the resonant frequencies of three different nuclides are realized simultaneously, and good electromagnetic isolation performance is displayed among the mutual frequencies.
The embodiment of the invention provides a four-end ring birdcage radio frequency coil system supporting three nuclide imaging, which comprises:
a first end ring, a second end ring, a third end ring, and a fourth end ring disposed about a central axis, the second end ring positioned between the first end ring and the third end ring, the third end ring positioned between the second end ring and the fourth end ring; at least one of the first end ring, the second end ring, the third end ring and the fourth end ring is provided with an excitation port;
a plurality of first conductive lines, a plurality of second conductive lines, and a plurality of third conductive lines, all parallel to the central axis; the first wire is connected between the first end ring and a second end ring, the second wire is connected between the second end ring and a third end ring, and the third wire is connected between the third end ring and a fourth end ring;
and the double-harmonic circuit is electrically connected with the excitation port and is used for realizing the resonant frequencies of the two nuclides.
Optionally, the capacitor further comprises a plurality of first capacitors, a plurality of second capacitors, a plurality of third capacitors and a plurality of fourth capacitors;
the first capacitor is connected in series in the first end ring, the second capacitor is connected in series in the second end ring, the third capacitor is connected in series in the third end ring, and the fourth capacitor is connected in series in the fourth end ring.
Optionally, a plurality of fifth capacitors, a plurality of sixth capacitors and a plurality of seventh capacitors are further included;
the fifth capacitor is connected in series in the first conducting wire, the sixth capacitor is connected in series in the second conducting wire, and the seventh capacitor is connected in series in the third conducting wire.
Optionally, along the extending direction of the central axis, the length of the first conducting wire is smaller than that of the second conducting wire, and the length of the third conducting wire is smaller than that of the second conducting wire.
Optionally, along the extending direction of the central axis, the length of the first conducting wire is equal to the length of the third conducting wire.
Optionally, the width of the first conductive line, the width of the second conductive line and the width of the third conductive line are equal.
Optionally, the first end ring is provided with two excitation ports, and the phase difference between the two excitation ports in the first end ring is 90 °;
the dual tuning circuit is electrically connected to an excitation port in the first end ring.
Optionally, an excitation port in the first end ring produces a resonant frequency of a first nuclear species and a resonant frequency of a second nuclear species;
the second end ring is provided with two excitation ports, and the phase difference between the two excitation ports in the second end ring is 90 degrees;
an excitation port in the second end ring produces a resonant frequency of a third nuclear species; the resonant frequency of the third nuclear species is less than the resonant frequency of the first nuclear species and the resonant frequency of the third nuclear species is less than the resonant frequency of the second nuclear species.
Optionally, the double-tuning circuit includes a first variable capacitor, a second variable capacitor, a third variable capacitor, a fourth variable capacitor, a fifth variable capacitor, and an inductor;
the first pole plate of the first variable capacitor is electrically connected with the first end of the excitation source, and the second pole plate of the first variable capacitor is electrically connected with the first pole plate of the second variable capacitor;
the second polar plate of the second variable capacitor is electrically connected with one end of the excitation port;
the first pole plate of the third variable capacitor is electrically connected with the second end of the excitation source, and the second pole plate of the third variable capacitor is electrically connected with the first pole plate of the fourth variable capacitor;
a second plate of the fourth variable capacitor is electrically connected with a second end of the excitation port;
the first plate of the fifth variable capacitor is electrically connected with the second plate of the first variable capacitor, and the second plate of the fifth variable capacitor is electrically connected with the second plate of the third variable capacitor;
the first end of the inductance coil is electrically connected with the second plate of the first variable capacitor, and the second end of the inductance coil is electrically connected with the second plate of the third variable capacitor.
Optionally, a shielding layer may be further included, the first end ring, the second end ring, the third end ring, the fourth end ring, the first wire, the second wire, and the third wire all being located within the shielding layer.
The embodiment of the invention provides a four-end ring birdcage radio frequency coil system supporting three-nuclide imaging, and a structure formed by a first end ring, a second end ring and a first wire can be regarded as a first birdcage structure. The structure formed by the second end ring, the third end ring, and the second wire can be considered a second birdcage structure. The structure formed by the third end ring, the fourth end ring, and the third conductive wire can be considered a third birdcage structure. Therefore, the birdcage radio frequency coil system provided by the embodiment of the invention adds two additional end rings to the conventional birdcage coil, which can be regarded as a combination of three birdcage structures. And a double-harmonic circuit is built at the excitation port, the birdcage structure of the double-harmonic circuit is built to realize the resonant frequency of two nuclides at the same time, and the other birdcage structures realize the resonant frequency of the other nuclide, so that the resonant frequencies of three different nuclides can be realized at the same time, good electromagnetic isolation performance is displayed among the mutual frequencies, and no additional loss element such as a diode switch is included.
Drawings
FIG. 1 is a schematic diagram of a four-terminal ring birdcage RF coil system supporting three-nuclear imaging according to an embodiment of the present invention;
FIG. 2 is a schematic view of the first end-ring of FIG. 1 in the XY-plane;
FIG. 3 is a schematic view of the second end ring of FIG. 1 in the XY-plane;
FIG. 4 is a schematic representation of the birdcage radio frequency coil system in FIG. 1 deployed in the XZ plane;
FIG. 5 is a schematic illustration of another birdcage RF coil system deployed in the XZ plane in accordance with an embodiment of the present invention;
FIG. 6 is a schematic view of another birdcage RF coil system deployed in the XZ plane in accordance with an embodiment of the present invention;
FIG. 7 is a circuit diagram of a dual tuning circuit provided by an embodiment of the present invention;
FIG. 8 is a schematic diagram of another four-terminal ring birdcage radio frequency coil system supporting three-nuclear species imaging according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In recent years, the study of aprotic (x-nuclear) MRI has attracted considerable interest, partly because of the increasing popularity of ultra-high field MRI. In which the magnetic resonance 23 Na， 31 The imaging of P and other polynucleotides is the unique imaging technology of important magnetic resonance molecular image for non-invasive acquisition of biological tissue physiological and metabolic information, 23 Na， 31 p and other x nuclei such as 19 F-imaging is challenging and dual or multi-resonant radio frequency coils are often used to meet this requirement.
Currently, a double-tuned coil can be designed in various ways, for example, a double-frequency is realized by building a double-tuned circuit or a trap circuit by using a pin diode control in a single-coil structure, or a double-frequency is realized by tuning every other leg or strut of a birdcage coil with a required frequency in a traditional birdcage structure, but the method depends on strong mutual coupling between meshes, and the symmetry of the coil is difficult to maintain. Or in combination with geometric isolation from each other, independent dual-tuned surface coils, or in an alternately nested birdcage configuration. By building completely different conductor geometries to create resonant modes at two frequencies. For the dual birdcage coil of the combined structure, a smaller diameter birdcage is centrally disposed in a larger diameter birdcage, the larger birdcage being tuned to a higher resonant frequency and the smaller birdcage being tuned to a lower frequency, thereby forming a dual tuned birdcage coil. One of the strongest sources of inductive coupling between birdcage units is the proximity of the end rings. Tuning of the coil is complicated by any "wiggling" of the two end rings relative to the orientation of the other ring, and misalignment of the two end rings can result in splitting of the linear modes at the two frequencies.
Fig. 1 is a schematic diagram of a four-end-ring birdcage radio-frequency coil system supporting three-nuclear-species imaging, fig. 2 is a schematic diagram of a first end ring in the XY plane in fig. 1, fig. 3 is a schematic diagram of a second end ring in the XY plane in fig. 1, and fig. 4 is an expanded schematic diagram of the birdcage radio-frequency coil system in the XZ plane in fig. 1, and referring to fig. 1 to 4, the four-end-ring birdcage radio-frequency coil system supporting three-nuclear-species imaging refers to a birdcage radio-frequency coil system capable of supporting three-nuclear-species imaging, and the birdcage radio-frequency coil system includes four end rings, respectively including a first end ring 11, a second end ring 12, a third end ring 13 and a fourth end ring 14. The first end ring 11, the second end ring 12, the third end ring 13 and the fourth end ring 14 are disposed to share a central axis K. The second end ring 12 is located between the first end ring 11 and the third end ring 13, and the third end ring 13 is located between the second end ring 12 and the fourth end ring 14. The first end ring 11, the second end ring 12, the third end ring 13, and the fourth end ring 14 are arranged in this order along the extending direction of the center axis K. At least one of the first end ring 11, the second end ring 12, the third end ring 13 and the fourth end ring 14 is provided with an excitation port 15. The birdcage radio frequency coil system also includes a plurality of first wires 21, a plurality of second wires 22, and a plurality of third wires 23. The first wire 21, the second wire 22 and the third wire 23 are all parallel to the central axis K. The first conductive wire 21 is connected between the first end ring 11 and the second end ring 12, the second conductive wire 22 is connected between the second end ring 12 and the third end ring 13, and the third conductive wire 23 is connected between the third end ring 13 and the fourth end ring 14. The birdcage radio frequency coil system also includes a dual-tuning circuit 30, the dual-tuning circuit 30 being electrically connected to the excitation port 15 for achieving resonant frequencies of the two nuclear species.
The embodiment of the invention provides a four-end ring birdcage radio frequency coil system supporting three-nuclide imaging, and a structure formed by a first end ring 11, a second end ring 12 and a first lead 21 can be regarded as a first birdcage structure. The structure formed by the second end ring 12, the third end ring 13, and the second wire 22 may be considered a second birdcage structure. The structure formed by the third end ring 13, the fourth end ring 14, and the third conductive wire 23 may be regarded as a third birdcage structure. Therefore, the birdcage radio-frequency coil system provided by the embodiment of the invention adds two additional end rings on the conventional birdcage coil, which can be regarded as the combination of three birdcage structures. And the double-harmonic circuit 30 is built at the excitation port 15, the birdcage structure of the double-harmonic circuit 30 is built to realize the resonant frequency of two nuclides at the same time, and the other birdcage structures realize the resonant frequency of the other nuclide, so that the resonant frequencies of three different nuclides can be realized at the same time, good electromagnetic isolation performance is displayed among the mutual frequencies, and no additional loss element such as a diode switch is included.
1-4, the birdcage radio frequency coil system further includes a plurality of first capacitors 51, a plurality of second capacitors 52, a plurality of third capacitors 53, and a plurality of fourth capacitors 54. A first capacitor 51 is connected in series in the first end-ring 11, a second capacitor 52 is connected in series in the second end-ring 12, a third capacitor 53 is connected in series in the third end-ring 13, and a fourth capacitor 54 is connected in series in the fourth end-ring 14. In the embodiment of the invention, the first capacitor 51, the second capacitor 52, the third capacitor 53 and the fourth capacitor 54 are respectively connected in series in the first end ring 11, the second end ring 12, the third end ring 13 and the fourth end ring 14, and the birdcage radio frequency coil system is tuned in a high-pass configuration, so that the resonant frequency of the nuclide can be changed by adjusting the capacitance values of the first capacitor 51, the second capacitor 52, the third capacitor 53 and the fourth capacitor 54.
For example, referring to fig. 1 to 4, the end rings (e.g., the first end ring 11, the second end ring 12, the third end ring 13, and the fourth end ring 14) include a plurality of circular arc-shaped conductors 10, a gap between two adjacent circular arc-shaped conductors 10 exists as an excitation port 15, one end of the excitation source 40 may be electrically connected to one circular arc-shaped conductor 10, the other end of the excitation source 40 may be electrically connected to another adjacent circular arc-shaped conductor 10, and the excitation source 40 applies an excitation signal to the end rings through the excitation port 15.
Exemplarily, referring to fig. 2, in the first end ring 11, the first capacitor 51 is connected between two adjacent circular arc-shaped conductors 10. Referring to fig. 3, in the second end ring 12, a second capacitor 52 is connected between two adjacent circular arc-shaped conductors 10. Similarly, in the third terminal ring 13, the third capacitor 53 is connected between two adjacent circular arc conductors 10. In the fourth end ring 14, a fourth capacitor 54 is connected between two adjacent circular arc-shaped conductors 10.
Alternatively, referring to fig. 1-2, the first end ring 11 opens with two excitation ports 15 (denoted as excitation port a and excitation port B, respectively). The two excitation ports 15 in the first end ring 11 are 90 out of phase. The double-tuning circuit 30 is electrically connected to the excitation port 15 in the first end ring 11. In the embodiment of the present invention, the first end ring 11 is provided with two excitation ports 15 with a phase difference of 90 °, and the first end ring 11 is excited by adopting a quadrature excitation method. The dual tuning circuit 30 achieves the resonant frequencies of both species.
Alternatively, referring to fig. 1 and 3, the excitation ports 15 in the first end ring 11 produce a resonant frequency of the first nuclear species and a resonant frequency of the second nuclear species. The second end ring 12 has two excitation ports 15 (denoted as excitation port C and excitation port D, respectively), and the two excitation ports 15 in the second end ring 12 are 90 ° out of phase. The excitation ports 15 in the second end ring 12 produce a resonant frequency of the third species. The resonant frequency of the third nuclear species is less than the resonant frequency of the first nuclear species and the resonant frequency of the third nuclear species is less than the resonant frequency of the second nuclear species. In the embodiment of the present invention, the second end ring 12 is provided with two excitation ports 15 with a phase difference of 90 °, and the second end ring 12 is excited by adopting a quadrature excitation method. The excitation port 15 in the second end ring 12 produces a resonant frequency of the third nuclear species based on the resonant frequencies of the two nuclear species achieved by the dual tuning circuit 30. Since the second end ring 12 generating a lower frequency is placed inside the first end ring 11 generating a higher frequency, the transmission efficiency is improved.
Illustratively, the first nuclear species is 1 H, the second nuclide is 19 F, the third nuclide is 23 And (4) Na. The double-harmonic circuit 30 is set up at the excitation port of the outer-end-ring high-pass birdcage, and mutual decoupling is realized at the same time 1 H、 19 F resonance frequency. The inner end ring is also of a high-pass structure and resonates at 23 Na operating frequency point. By adjusting the distance between the inner and outer end rings 1 H、 19 F nuclide and 23 the Na nuclide has good decoupling effect. For example, the system can be applied to 3T system and can simultaneously support 1 H/ 19 F/ 23 Precise excitation and reception of Na/signal. The 3T system is a magnetic field strength 3T (T is a magnetic field strength unit, tesla) system.
FIG. 5 is a schematic view of another birdcage RF coil system in accordance with an embodiment of the invention deployed in the XZ plane, and referring to FIG. 5, the birdcage RF coil system further includes a plurality of fifth capacitors 55, a plurality of sixth capacitors 56, and a plurality of seventh capacitors 57. A fifth capacitor 55 is connected in series with the first conductor 21, a sixth capacitor 56 is connected in series with the second conductor 22, and a seventh capacitor 57 is connected in series with the third conductor 23. In the embodiment of the present invention, the fifth capacitor 55, the sixth capacitor 56 and the seventh capacitor 57 are respectively connected in series with the first wire 21, the second wire 22 and the third wire 23, and the birdcage rf coil system is tuned in a low-pass configuration, so that the resonant frequency of the nuclear species can be changed by adjusting the capacitance values of the fifth capacitor 55, the sixth capacitor 56 and the seventh capacitor 57.
Illustratively, referring to fig. 5, the conductive lines (e.g., the first conductive line 21, the second conductive line 22, and the third conductive line 23) include two linear conductors 20, a fifth capacitor 55 is connected between two adjacent linear conductors 20, a sixth capacitor 56 is connected between two adjacent linear conductors 20, and a seventh capacitor 57 is connected between two adjacent linear conductors 20.
FIG. 6 is a schematic view of another birdcage RF coil system according to an embodiment of the invention deployed in an XZ plane, and referring to FIG. 6, the birdcage RF coil system further includes a plurality of first capacitors 51, a plurality of second capacitors 52, a plurality of third capacitors 53, a plurality of fourth capacitors 54, a plurality of fifth capacitors 55, a plurality of sixth capacitors 56, and a plurality of seventh capacitors 57. In the embodiment of the invention, the birdcage radio frequency coil system is tuned by a mixed-pass configuration, and the resonant frequency of the nuclide can be changed by adjusting the capacitance values of the first capacitor 51, the second capacitor 52, the third capacitor 53, the fourth capacitor 54, the fifth capacitor 55, the sixth capacitor 56 and the seventh capacitor 57.
Referring to fig. 1 and 4 in combination, along the extending direction of the central axis K, the length of the first conductive line 21 is smaller than the length of the second conductive line 22, and the length of the third conductive line 23 is smaller than the length of the second conductive line 22. In the embodiment of the present invention, the lengths of the first conductive line 23 and the third conductive line 23 are smaller than the length of the second conductive line 22, and the lengths of the conductive lines at the two ends are smaller than the length of the conductive line in the middle, so that the coupling effect between the nuclear species is reduced.
Alternatively, referring to fig. 1 and 4 in combination, the length of the first wire 21 is equal to the length of the third wire 23 along the extending direction of the central axis K.
Alternatively, referring to fig. 1 to 4 in combination, the width of the first conductive line 21, the width of the second conductive line 22 and the width of the third conductive line 23 are equal. That is, the width of the first conductive line 21 is equal to the width of the second conductive line 22, and the width of the second conductive line 22 is equal to the width of the third conductive line 23. Thereby improving the uniformity of the magnetic field strength. In other embodiments, at least two of the first conducting wire 21, the second conducting wire 22 and the third conducting wire 23 may have different widths, so as to form a non-uniform magnetic field strength, and thus, the magnetic resonance imaging device is suitable for magnetic resonance imaging of parts such as the abdomen.
Referring to fig. 7, the double-tuning circuit 30 includes a first variable capacitor C1, a second variable capacitor C2, a third variable capacitor C3, a fourth variable capacitor C4, a fifth variable capacitor C5, and an inductor L1. A first plate of the first variable capacitor C1 is electrically connected to a first terminal of the excitation source 40, and a second plate of the first variable capacitor C1 is electrically connected to a first plate of the second variable capacitor C2. The second plate of the second variable capacitor C2 is electrically connected to one end of the excitation port 15 (i.e., one circular arc shaped conductor 10). The first plate of the third variable capacitor C3 is electrically connected to the second terminal of the excitation source 40, and the second plate of the third variable capacitor C3 is electrically connected to the first plate of the fourth variable capacitor C4. The second plate of the fourth variable capacitor C4 is electrically connected to the second end of the excitation port 15 (i.e., the other circular arc shaped conductor 10). The first plate of the fifth variable capacitor C5 is electrically connected to the second plate of the first variable capacitor C1, and the second plate of the fifth variable capacitor C5 is electrically connected to the second plate of the third variable capacitor C3. A first terminal of the inductor L1 is electrically connected to the second plate of the first variable capacitor C1, and a second terminal of the inductor L1 is electrically connected to the second plate of the third variable capacitor C3. A fifth variable capacitor C5 is connected in parallel with inductor L1.
Fig. 8 is a schematic diagram of another four-end-ring birdcage radio-frequency coil system supporting three-nuclear-species imaging according to an embodiment of the present invention, and referring to fig. 1 to 8, the birdcage radio-frequency coil system includes a birdcage radio-frequency coil 100, and the birdcage radio-frequency coil 100 includes the first end ring 11, the second end ring 12, the third end ring 13, the fourth end ring 14, the first conductive wire 21, the second conductive wire 22, and the third conductive wire 23 in the above-described embodiment. The birdcage radio-frequency coil system can further include a shielding layer 60, the shielding layer 60 is located at the periphery of the birdcage radio-frequency coil 100, the first end ring 11, the second end ring 12, the third end ring 13, the fourth end ring 14, the first wire 21, the second wire 22, and the third wire 23 are all located in the shielding layer 60, and the shielding layer 60 can reduce the amplitude of interference signals and protect external radiation of the radio-frequency signals.
In the above embodiments, the number of any two of the first conductive lines 21, the second conductive lines 22, and the third conductive lines 23 is equal. The number of the first conductive lines 21, the second conductive lines 22, and the third conductive lines 23 is not limited in the present invention. In the above embodiments, the first conductive line 21, the second conductive line 22, and the third conductive line 23 are all 8 as an example, and in other embodiments, the number of the first conductive line, the second conductive line, and the third conductive line may be 4, 16, or 32.
Illustratively, the shield 60 forms a cylindrical surface around the central axis K, the cylindrical surface having a diameter of 20cm, a length of 23cm, and a thickness of 0.15 mm. The material may be pure copper. The first end ring 11, the second end ring 12, the third end ring 13 and the fourth end ring 14 may have a diameter of 18 cm. The length of the second wire 22 is 13 cm. The capacitance values of the first capacitor 51, the second capacitor 52, the third capacitor 53 and the fourth capacitor 54 are adjusted to enable the resonance to be in a 3T systemLower part 23 Na operating frequency (33.9 MHz). The width and the length of the lead of the link can be optimized to ensure that the optimal transmitting field uniformity and high emissivity under the target frequency are obtained. The first wire 21 and the third wire 23 each have a length of 2.5 cm. Dual tuning circuit 30 implementation 1 H/ 19 Accurate excitation and reception of F frequency (128.2MHz/120.6MHz), keeping the circuit the same at excitation port a and excitation port B, there may be a small difference in the circuit parameter values.
Optionally, the birdcage radio-frequency coil system may further include a radio-frequency transceiver switch, and the radio-frequency transceiver switch is electrically connected to the excitation port and is configured to excite and acquire a magnetic resonance nuclide signal, that is, to implement a transceiver function.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (9)

1. A four-terminal ring birdcage radio frequency coil system supporting three nuclear species imaging, comprising:
a first end ring, a second end ring, a third end ring, and a fourth end ring disposed about a central axis, the second end ring positioned between the first end ring and the third end ring, the third end ring positioned between the second end ring and the fourth end ring; at least one of the first end ring, the second end ring, the third end ring and the fourth end ring is provided with an excitation port;
a plurality of first conductive lines, a plurality of second conductive lines, and a plurality of third conductive lines, all parallel to the central axis; the first conductive wire is connected between the first end ring and a second end ring, the second conductive wire is connected between the second end ring and the third end ring, and the third conductive wire is connected between the third end ring and the fourth end ring;
the double-harmonic circuit is electrically connected with the excitation port and is used for realizing the resonant frequency of two nuclides;
the double-tuning circuit comprises a first variable capacitor, a second variable capacitor, a third variable capacitor, a fourth variable capacitor, a fifth variable capacitor and an inductance coil;
the first pole plate of the first variable capacitor is electrically connected with the first end of the excitation source, and the second pole plate of the first variable capacitor is electrically connected with the first pole plate of the second variable capacitor;
the second polar plate of the second variable capacitor is electrically connected with one end of the excitation port;
the first pole plate of the third variable capacitor is electrically connected with the second end of the excitation source, and the second pole plate of the third variable capacitor is electrically connected with the first pole plate of the fourth variable capacitor;
a second plate of the fourth variable capacitor is electrically connected with a second end of the excitation port;
the first plate of the fifth variable capacitor is electrically connected with the second plate of the first variable capacitor, and the second plate of the fifth variable capacitor is electrically connected with the second plate of the third variable capacitor;
the first end of the inductance coil is electrically connected with the second plate of the first variable capacitor, and the second end of the inductance coil is electrically connected with the second plate of the third variable capacitor.
2. The birdcage radio frequency coil system of claim 1, further comprising a plurality of first capacitances, a plurality of second capacitances, a plurality of third capacitances, and a plurality of fourth capacitances;
the first capacitor is connected in series in the first end ring, the second capacitor is connected in series in the second end ring, the third capacitor is connected in series in the third end ring, and the fourth capacitor is connected in series in the fourth end ring.
3. The birdcage radio frequency coil system of claim 1, further comprising a fifth plurality of capacitors, a sixth plurality of capacitors, and a seventh plurality of capacitors;
the fifth capacitor is connected in series in the first conducting wire, the sixth capacitor is connected in series in the second conducting wire, and the seventh capacitor is connected in series in the third conducting wire.
4. The birdcage radio frequency coil system according to claim 1, wherein a length of the first wire is less than a length of the second wire and a length of the third wire is less than a length of the second wire along an extent of the central axis.
5. The birdcage radio frequency coil system of claim 4, wherein a length of the first wire is equal to a length of the third wire along an extension of the central axis.
6. The birdcage radio frequency coil system of claim 1, wherein a width of the first wire, a width of the second wire, and a width of the third wire are equal.
7. The birdcage radio frequency coil system according to claim 1, wherein the first end ring opens two of the excitation ports, the two excitation ports in the first end ring being 90 ° out of phase with each other;
the dual tuning circuit is electrically connected to an excitation port in the first end ring.
8. The birdcage radio frequency coil system of claim 7, wherein an excitation port in the first end ring produces a resonant frequency of a first nuclear species and a resonant frequency of a second nuclear species;
the second end ring is provided with two excitation ports, and the phase difference between the two excitation ports in the second end ring is 90 degrees;
an excitation port in the second end ring produces a resonant frequency of a third nuclear species; the resonant frequency of the third nuclear species is less than the resonant frequency of the first nuclear species and the resonant frequency of the third nuclear species is less than the resonant frequency of the second nuclear species.
9. The birdcage radio frequency coil system of claim 1, further comprising a shielding layer, the first end ring, the second end ring, the third end ring, the fourth end ring, the first wire, the second wire, and the third wire each being positioned within the shielding layer.
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Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6396271B1 (en) * 1999-09-17 2002-05-28 Philips Medical Systems (Cleveland), Inc. Tunable birdcage transmitter coil
CN100526906C (en) * 2002-11-27 2009-08-12 皇家飞利浦电子股份有限公司 Degenerate birdcage coil and transmit/receive apparatus and method for same
RU2008143402A (en) * 2006-04-05 2010-05-10 Конинклейке Филипс Электроникс, Н.В. (Nl) TWO-RESONANCE RECEIVER TRANSFER SOLENOID COIL FOR MAGNETIC RESONANCE TOMOGRAPHY (MRI)
DE102006050069B4 (en) * 2006-10-24 2011-07-07 Siemens AG, 80333 Birdcage resonator with coupling rings in addition to the end rings
CN101896830A (en) * 2007-12-13 2010-11-24 皇家飞利浦电子股份有限公司 Dual tuned volume coils adapted to provide an end ring mode
US8035384B2 (en) * 2008-10-23 2011-10-11 General Electric Company Hybrid birdcage-TEM radio frequency (RF) coil for multinuclear MRI/MRS
WO2014053289A1 (en) * 2012-10-02 2014-04-10 Koninklijke Philips N.V. Birdcage body coil for parallel transmit mri
CN106950520B (en) * 2017-05-20 2020-06-26 深圳市金石医疗科技有限公司 Self-generating and self-receiving birdcage array coil and control circuit thereof
CN208488538U (en) * 2018-06-15 2019-02-12 西门子(深圳)磁共振有限公司 A kind of neck coil and magnetic resonance imaging system
CN108680882B (en) * 2018-06-28 2019-08-27 深圳先进技术研究院 A kind of double-core coil device and double-core radio frequency array lines coil apparatus
CN110488211A (en) * 2019-08-31 2019-11-22 宽腾(杭州)医疗影像设备有限公司 A kind of adjustable birdcage-type radio frequency coil for MRI MRS
CN110703169A (en) * 2019-11-20 2020-01-17 深圳先进技术研究院 Multi-channel radio frequency coil device and nuclear magnetic resonance imaging system
CN112649774A (en) * 2020-12-18 2021-04-13 中国科学院深圳先进技术研究院 Double-tuning radio frequency coil device

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