Up-down covering super-high density magnetic resonance heart coil, flexible heart coil assembly and heart magnetic resonance imager

Abstract

The invention discloses an up-down covering super-high density magnetic resonance heart coil, a flexible heart coil assembly and a heart magnetic resonance imager. The up-down covering super-high density magnetic resonance heart coil comprises a plurality of first-class coils, and each first-class coil is at least partially overlapped with three adjacent first-class coils. According to the coil arrangement method of the up-down covering super-high density magnetic resonance heart coil provided by the invention, high density array arrangement of the coil can be realized, and the high density coil array of the coil can bring a flatter signal-to-noise ratio distribution curve and a higher signal-to-noise ratio expression in a water model deep part (approximate to the heart depth).

Description

Technical Field

[0001] This application relates to the field of cardiac magnetic resonance imaging technology, specifically to an ultra-high density cardiac magnetic resonance coil with upper and lower coverage, a flexible cardiac coil assembly, and a cardiac magnetic resonance imaging instrument. Background Technology

[0002] Cardiac magnetic resonance imaging (CMR) plays an irreplaceable role in the diagnosis, treatment evaluation, and scientific research of cardiovascular diseases due to its non-invasive and high-resolution characteristics. High-quality cardiac images depend on a high signal-to-noise ratio (SNR), stable parallel imaging performance, and a comfortable patient experience during the scanning process. Current clinical cardiac scans commonly use a combination of abdominal coils (covering the anterior chest) and spinal coils (covering the back). While this method can cover the cardiac region, it has the following drawbacks: First, the abdominal and spinal coils were not originally designed for the heart; their coil cell size, array density, and geometric layout are not optimal, resulting in structural asymmetry and uneven signal reception efficiency in the cardiac region. Second, the cell size and array density of the two types of coils are often mismatched, causing significant differences in the SNR and parallel imaging performance between the anterior and posterior images, leading to a decrease in overall image quality.

[0003] Currently, some radiofrequency coils specifically designed for cardiac use exist on the market, but they mostly employ semi-rigid or rigid structures based on rigid circuit boards. These coils perform poorly in conforming to the human body's contours, especially in areas such as the upper chest, neck, and armpit, where they cannot achieve a tight fit. This poor fit results in a low fill factor, reducing the signal-to-noise ratio of the final image and affecting the acceleration factor of parallel imaging. Furthermore, rigid materials and protruding electronic component housings can cause patient discomfort and may introduce motion artifacts during scanning due to patient movement. In addition, flexibility and multimodal compatibility are insufficient. A large number of rigid components, such as matching, tuning, and preamplifier circuits, are distributed in the imaging area, affecting flexible design and potentially causing safety and compatibility issues during combined PET / MR scanning. Therefore, existing technologies struggle to achieve a balance between high-density arrays, imaging consistency, patient comfort, and multimodal compatibility.

[0004] Specifically, the existing technology has the following disadvantages:

[0005] (1) Imaging signal imbalance. Existing schemes often use abdominal coil and spinal coil for combined scanning. Due to the different unit sizes and array densities of the upper and lower coils, the signal intensity in the anterior and posterior directions of the heart is inconsistent, which reduces the image signal-to-noise ratio and affects the parallel imaging speed and accuracy.

[0006] (2) Limited parallel imaging performance. Traditional rigid cardiac coils have insufficient unit density, small overlap ratio, sparse array, and limited acceleration capability, making it difficult to meet the needs of rapid dynamic cardiac imaging.

[0007] (3) Poor patient comfort and fit. Existing rigid coils cannot conform well to complex body surface structures such as the neck, armpit and chest, making positioning difficult, causing strong pressure, reducing patient compliance, and indirectly affecting image quality.

[0008] (4) Insufficient flexibility and multimodal compatibility. Rigid circuit components such as matching, tuning, and preamplifiers are widely distributed in the imaging area, limiting flexible design. Furthermore, they are prone to signal interference and safety risks during PET / MR combined scanning. Summary of the Invention

[0009] The purpose of this invention is to provide an ultra-high density magnetic resonance cardiac coil with top and bottom coverage to at least solve one of the above-mentioned technical problems.

[0010] One aspect of the present invention provides an ultra-high density magnetic resonance cardiac coil with top and bottom coverage, the ultra-high density magnetic resonance cardiac coil with top and bottom coverage comprising:

[0011] The first type of coil, there are multiple first type coils, and each first type coil partially overlaps with at least three adjacent first type coils.

[0012] Optionally, the area of ​​the overlapping portion of every two first-class coils accounts for at least one-seventh to one-third of the total area of ​​the first-class coils.

[0013] Optionally, the upper and lower covering ultra-high density magnetic resonance cardiac coil further includes:

[0014] The central coil, which is a plurality of such central coils, is covered by a plurality of first-type coils, the area covered by each first-type coil being at least equal to the total area of ​​the central coil. The central coil is used to be placed at the heart position of the user when the ultra-high density magnetic resonance cardiac coil covering the upper and lower parts is used.

[0015] Optionally, each first-type coil that overlaps with the central coil has an area of ​​at least 50% of the area of ​​the central coil.

[0016] This application also provides a flexible cardiac coil assembly, which includes an ultra-high density magnetic resonance cardiac coil with upper and lower coverings as described above.

[0017] Optionally, the flexible cardiac coil assembly further includes:

[0018] The torso base has a rectangular surface, and one side of the torso base is provided with an ultra-high density magnetic resonance cardiac coil as described above.

[0019] The neck and axillary flexible base has one side connected to the trunk base. The two ends of the side of the neck and axillary flexible base connected to the trunk base are in the length direction. The distance between the two ends of the side of the neck and axillary flexible base connected to the trunk base is a first length. The side of the neck and axillary flexible base connected to the trunk base extends away from the trunk base in a gradually narrowing manner in the length direction to form another side. The distance between the two ends of the other side is less than the first length. The neck and axillary flexible base includes an ultra-high density magnetic resonance cardiac coil that covers the neck and axillary area as described above.

[0020] Optionally, the flexible cardiac coil assembly further includes:

[0021] The back base has a rectangular surface, and one side of the back base is provided with an ultra-high density magnetic resonance cardiac coil as described above.

[0022] This application also provides a cardiac magnetic resonance imaging (MRI) device, which includes the flexible cardiac coil assembly described above.

[0023] Optionally, the cardiac magnetic resonance imaging system further includes:

[0024] The circuit within the imaging range includes a small matching circuit and a detuning circuit group; wherein...

[0025] The input terminal of the small matching circuit is connected to the output terminal of the cardiac coil unit, and the output terminal of the small matching circuit is connected in series with the input terminal of the detuned circuit group.

[0026] Optionally, the detuning circuit group includes an active detuning circuit and a passive detuning circuit; wherein, the input terminal of the active detuning circuit is connected to the output terminal of a small matching circuit, and the passive detuning circuit is connected in series in the coil conductor;

[0027] The output terminal of the active detuning circuit is connected to the input terminal of the phase shifter.

[0028] The coil arrangement method for the ultra-high density magnetic resonance cardiac coils with upper and lower coverage provided in this application can achieve a high-density array arrangement of coils. The high-density coil array can bring a flatter signal-to-noise ratio distribution curve and a higher signal-to-noise ratio performance in the deep part of the water model (approximate to the depth of the heart). Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the upper and lower covering ultra-high density magnetic resonance cardiac coil of the first embodiment of this application.

[0030] Figure 2 This is a schematic diagram comparing the signal-to-noise ratio of the coil structure water model according to the first embodiment of this application.

[0031] Figure 3 This is a schematic diagram of the structure of the upper and lower covering ultra-high density magnetic resonance cardiac coil of the second embodiment of this application.

[0032] Figure 4 This is another structural schematic diagram of the upper and lower covering ultra-high density magnetic resonance cardiac coil of the second embodiment of this application.

[0033] Figure 5 This is a schematic diagram of the torso, neck, and armpit heart coil structure in a flexible heart coil assembly according to an embodiment of this application.

[0034] Figure 6 This is a schematic diagram of the back of the heart coil structure in a flexible heart coil assembly according to an embodiment of this application.

[0035] Figure 7 This is a schematic diagram of a cardiac magnetic resonance imaging (MRI) device according to an embodiment of this application.

[0036] Figure 8 This is a schematic diagram of the front-end circuit of a cardiac coil unit according to an embodiment of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] like Figure 1 The upper and lower covering ultra-high density MRI cardiac coil shown includes:

[0039] The first type of coil, there are multiple first type coils, and each first type coil partially overlaps with at least three adjacent first type coils.

[0040] See Figure 2 , Figure 2 Structures one and two are existing technologies (sparse arrays), while structure three is... Figure 1 The signal-to-noise ratio distribution of the three coil structures at a depth of 10 cm in water was numerically calculated and performance evaluated for the coil arrangement shown. The results are as follows: Figure 2As shown, high-density coil arrays exhibit a flatter signal-to-noise ratio distribution curve and higher signal-to-noise ratio performance at depths in the water model (approximately the depth of the heart).

[0041] In this embodiment, the area of ​​the overlapping portion of every two first-type coils accounts for at least one-seventh to one-third of the total area of ​​the first-type coils.

[0042] See Figure 2 In this embodiment, the upper and lower covering ultra-high density magnetic resonance cardiac coil further includes:

[0043] The central coil, which is a plurality of such central coils, is covered by a plurality of first-type coils, the area covered by each first-type coil being at least equal to the total area of ​​the central coil. The central coil is used to be placed at the heart position of the user when the ultra-high density magnetic resonance cardiac coil covering the upper and lower parts is used.

[0044] In this embodiment, each first-type coil that overlaps with the central coil has an area of ​​at least 50% of the area of ​​the central coil.

[0045] Figure 2 The ultra-high density MRI cardiac coil shown uses an ultra-high density petal-shaped coil structure. The central unit of the array (central coil) is directly facing the heart. The surrounding units overlap the central unit with a large area (50%) to increase the overall coil array density, and radiate outward from the central unit to increase the number of coil units and increase the coil coverage area.

[0046] See Figures 3 to 6 This application also provides a flexible cardiac coil assembly, which includes an ultra-high density magnetic resonance cardiac coil with upper and lower coverings as described above.

[0047] In this embodiment, the flexible cardiac coil assembly further includes:

[0048] The torso base has a rectangular surface, and one side of the torso base is provided with an ultra-high density magnetic resonance cardiac coil as described above.

[0049] The neck and axillary flexible base has one side connected to the trunk base. The two ends of the side of the neck and axillary flexible base connected to the trunk base are in the length direction. The distance between the two ends of the side of the neck and axillary flexible base connected to the trunk base is a first length. The side of the neck and axillary flexible base connected to the trunk base extends away from the trunk base in a gradually narrowing manner in the length direction to form another side. The distance between the two ends of the other side is less than the first length. The neck and axillary flexible base includes an ultra-high density magnetic resonance cardiac coil that covers the neck and axillary area as described above.

[0050] In this embodiment, the flexible cardiac coil assembly further includes:

[0051] The back base has a rectangular surface, and one side of the back base is provided with an ultra-high density magnetic resonance cardiac coil as described above.

[0052] In this embodiment, the torso portion of this patent adopts a normal rectangular shape, conforming to the lower half of the torso. The flexible portions of the neck and armpits employ special shape cutting and mechanical encapsulation to fit the contours of the upper torso, including the neck and armpits. When the upper and lower portions are used together, the overall coverage and containment of the cardiac imaging area are improved, and the overall image quality is enhanced by utilizing orthogonal radio frequency fields.

[0053] In this embodiment, the upper and lower ultra-high density MRI cardiac coils covering the torso and the upper and lower ultra-high density MRI cardiac coils covering the back both use the same unit size and density, avoiding signal differences caused by traditional asymmetrical designs. After the upper and lower arrays are combined, a balanced signal is obtained in the anterior-posterior direction of the heart.

[0054] See Figure 7 as well as Figure 8 This application also provides a cardiac magnetic resonance imaging (MRI) device, which includes the flexible cardiac coil assembly described above.

[0055] In this embodiment, the cardiac magnetic resonance imaging system further includes:

[0056] The circuit within the imaging range includes a small matching circuit and a detuning circuit group; wherein...

[0057] The input terminal of the small matching circuit is connected to the output terminal of the cardiac coil unit, and the output terminal of the small matching circuit is connected in series with the input terminal of the detuned circuit group.

[0058] See Figure 8In this embodiment, the flexible cardiac coil assembly is connected to the input of a small matching circuit in the imaging range circuit. The output of the small matching circuit is connected to the input of the detuned circuit group. The output of the detuned circuit group is connected to the input of the phase shifter. The output of the phase shifter is connected to the input of the preamplifier in the adapter box. The output of the preamplifier is connected to the input of the notch filter in the adapter box. The output of the notch filter serves as the signal endpoint and is connected to the cardiac magnetic resonance (or PET / MR combined) imaging system.

[0059] In this embodiment, the detuning circuit group includes an active detuning circuit and a passive detuning circuit; wherein, the input terminal of the active detuning circuit is connected to the output terminal of the small matching circuit, and the passive detuning circuit is connected in series in the coil conductor;

[0060] The output terminal of the active detuning circuit is connected to the input terminal of the phase shifter.

[0061] In this embodiment, the passive detuning circuit is as follows: Figure 8 The structure within the dashed box (No. 1) is shown, including the passive detuning capacitor. Passive detuning inductor And two passively detuned diodes connected in reverse parallel. .

[0062] In this embodiment, the active detuning circuit is as follows: Figure 8 The structure within the dashed box in section 2 is shown, including the active detuning inductor. Active detuning capacitor 1 active detuning diode .

[0063] In this embodiment, one end of the passive detuning capacitor is connected to the inductor in the passive detuning circuit. One end of the passively detuned capacitor is connected to the other end of the passively detuned diode. Anode and passively detuned diode The common terminal of the cathode (to realize) and (The starting point of the reverse parallel connection).

[0064] passive detuned diode The cathode, and the passively detuned diode Anode connection (forming) The end point of the anti-parallel structure is the output terminal of the passively detuned circuit.

[0065] The core function of this anti-parallel structure is to control via radio frequency transmission signals. On / off switching serves as a backup detuning mechanism in the event of active detuning failure.

[0066] The output terminals of the passively detuned circuit are connected to the coil tuning capacitor. ;

[0067] Active detuning circuits such as Figure 8 The structure within the dashed box (No. 2) shows the inductor in the active detuning circuit. One end is connected to an active detuning capacitor. One end, after connection and The two ends are connected to the diode. At both ends of the diode. When the DC control signal is turned on, the same LC parallel resonant basic structure is formed, and a detuned high impedance is formed at the coil port, thus realizing the detuning of the receiving coil unit.

[0068] The matching circuit also uses Figure 8 The structure within the dashed box (No. 2) has its output connected to a coaxial transmission line. Connected to the input of the phase shifter, the phase shifter is like... Figure 8 The structure within the dashed box (No. 3) is shown. In this embodiment, one end of C7 is connected to the output terminal of the passive detuning circuit (the common terminal of the anode of D2 and the cathode of D3), and the other end is connected to the coil unit conductor. C8 is symmetrically arranged with C7, one end connected to the same passive detuning circuit output terminal, and the other end connected to another conductor of the coil unit, forming a multi-capacitor parallel tuning structure with C5 and C6. One end of L4 is connected to the output conductor of the coil unit, and the other end is connected to the common connection point of C5 and C7 (or the common connection point of C6 and C8), forming a series link of "coil → L4 → tuning capacitor → passive detuning circuit". The anode of D4 is connected to the common terminal of the anode of D2 and the cathode of D3, and the cathode is connected to the common connection point of the tuning capacitors (C5 / C7), forming a parallel backup or series protection for D2 and D3.

[0069] In this embodiment, the same unit size and array density are used in both the upper and lower parts to avoid signal unevenness and ensure consistent imaging quality in the upper and lower parts of the heart region.

[0070] A high-density, petal-like overlapping layout is employed. With the central element aligned directly with the heart-shaped area, the remaining elements are arranged in a petal-like pattern around it, with approximately 50% overlap between adjacent elements. This increases array density within a limited space, enhancing penetration depth and parallel imaging capabilities. To evaluate the signal-to-noise ratio (SNR) performance of different coil density structures at depths of the scanning phantom, SNR numerical calculations were performed based on coil structures of varying densities.

[0071] The upper coil of this application adopts a specially cut shape to conform to the complex curves of the body surface such as the neck and armpits; the lower coil maintains a rectangular shape to enhance the fit of the lower chest and abdomen, achieving overall area coverage and body conformity.

[0072] This application retains only small matching and detuning circuits within the imaging area, while the remaining larger circuits (preamplifiers, notch filters, etc.) are moved to the outside of the imaging area via transmission lines and centrally arranged. This scheme not only improves coil flexibility and comfort but also is compatible with PET / MR scanning. Specifically, (4) larger rigid circuits such as preamplifiers and notch filters are moved outside the imaging area via transmission lines, thereby improving coil flexibility and comfort during use. Furthermore, since the high-loss X-ray circuits are moved outside the imaging area, the cardiac coil design in this invention is also applicable to PET / MR scanning. The low-noise preamplifiers are centrally placed in the adapter box, and the upper and lower cardiac coil arrays are connected to the adapter box via transmission lines for image scanning.

[0073] This application transmits the signal to a junction box for centralized amplification via a transmission line, and employs active and passive detuning circuits to reduce the impact of the receiving array on the transmitting field. Simultaneously, a phase shifter is used to adjust the preamplifier decoupling, effectively reducing coupling between receiving channels and improving multi-channel independence.

[0074] In this patent, the coil channel uses a combination of passive and active detuning circuits to improve the detuning effect of the receiving unit during system transmission. Simultaneously, after matching, the coil is connected to a preamplifier in the adapter box via a transmission line for signal amplification. A phase shifter is added to the link for phase adjustment to achieve preamplifier decoupling and reduce the coupling between adjacent channels.

[0075] This application has the following advantages:

[0076] The upper and lower coil arrays are completely identical in terms of unit size, array density, and layout, achieving a balance between the penetration depth of imaging signals in the anterior-posterior direction of the heart and parallel imaging performance. This solves the signal inconsistency problem caused by the existing combination of abdominal and spinal coils.

[0077] The cells are arranged around the central cell with an overlap of approximately 50% of the area, forming a high-density radio frequency array, which significantly improves the signal-to-noise ratio (SNR) and parallel imaging acceleration factor (g-factor) performance.

[0078] The upper coil uses a specially cut contour for complex body surfaces such as the neck and armpits, while the lower coil adopts a rectangular structure; the overall structure can conform to the curve of the chest, achieving better patient fit and comfort.

[0079] Only small matching and detuning circuits are retained within the imaging range. Rigid circuit components such as preamplifiers and notch filters are moved to a junction box outside the imaging area via flexible transmission lines, which improves flexibility and PET / MR compatibility and simplifies clinical operation.

[0080] An active and passive detuning circuit is set in the coil channel to ensure reliable detuning during system transmission; a phase shifter is added to the signal link for phase adjustment to achieve preamplifier decoupling, significantly reduce channel coupling, and enhance multi-channel independence and image stability.

[0081] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A high-density magnetic resonance cardiac coil with top and bottom coverage, characterized in that, The upper and lower covering ultra-high density magnetic resonance cardiac coils include: The first type of coil, there are multiple first type coils, and each first type coil partially overlaps with at least three adjacent first type coils.

2. The ultra-high density magnetic resonance cardiac coil with upper and lower coverage as described in claim 1, characterized in that, The area of ​​the overlapping portion of any two Class I coils shall account for at least one-seventh to one-third of the total area of ​​the Class I coils.

3. The ultra-high density magnetic resonance cardiac coil with upper and lower coverage as described in claim 2, characterized in that, The upper and lower covering ultra-high density magnetic resonance cardiac coil further includes: The central coil, which is a plurality of such central coils, is covered by a plurality of first-type coils, the area covered by each first-type coil being at least equal to the total area of ​​the central coil. The central coil is used to be placed at the heart position of the user when the ultra-high density magnetic resonance cardiac coil covering the upper and lower parts is used.

4. The ultra-high density magnetic resonance cardiac coil with upper and lower coverage as described in claim 3, characterized in that, Each first-type coil that overlaps with the central coil has an area of ​​at least 50% of the area of ​​the central coil.

5. A flexible cardiac coil assembly, characterized in that, The flexible cardiac coil assembly includes an ultra-high density magnetic resonance cardiac coil with upper and lower covering as described in any one of claims 1 to 4.

6. The flexible cardiac coil assembly as described in claim 5, characterized in that, The flexible cardiac coil assembly further includes: The torso base has a rectangular surface, and one side of the torso base is provided with an ultra-high density magnetic resonance cardiac coil as described in any one of claims 1 to 4. A flexible base for the neck and armpit, one side of which is connected to a trunk base, the two ends of the side of the neck and armpit flexible base connected to the trunk base are in the length direction, the distance between the two ends of the side of the neck and armpit flexible base connected to the trunk base is a first length, the side of the neck and armpit flexible base connected to the trunk base extends away from the trunk base in a gradually narrowing manner in the length direction to form another side, the distance between the two ends of the other side is less than the first length; the flexible base for the neck and armpit includes an ultra-high density magnetic resonance cardiac coil covering the upper and lower parts as described in any one of claims 1 to 4.

7. The flexible cardiac coil assembly as claimed in claim 6, characterized in that, The flexible cardiac coil assembly further includes: The back base has a rectangular surface, and one side of the back base is provided with an ultra-high density magnetic resonance cardiac coil as described in any one of claims 1 to 4.

8. A cardiac magnetic resonance imaging (MRI) device, characterized in that, The cardiac magnetic resonance imaging system includes the flexible cardiac coil assembly as described in any one of claims 5 to 7.

9. The cardiac magnetic resonance imaging system as described in claim 8, characterized in that, The cardiac magnetic resonance imaging system further includes: The circuit within the imaging range includes a small matching circuit and a detuning circuit group; wherein... The input terminal of the small matching circuit is connected to the output terminal of the cardiac coil unit, and the output terminal of the small matching circuit is connected in series with the input terminal of the detuned circuit group.

10. The cardiac magnetic resonance imaging system as described in claim 9, characterized in that, The detuning circuit group includes an active detuning circuit and a passive detuning circuit; The input terminal of the active detuning circuit is connected to the output terminal of the small matching circuit, and the passive detuning circuit is connected in series in the coil conductor. The output terminal of the active detuning circuit is connected to the input terminal of the phase shifter.

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