Brace-shaped magnetic resonance oral wireless coil, and magnetic resonance imaging device

Abstract

A brace-shaped magnetic resonance oral wireless coil, and a magnetic resonance imaging device. The magnetic resonance oral wireless coil comprises a plurality of wireless resonant rings (10) and a flexible substrate (20), wherein each wireless resonant ring (10) is of a flexible loop structure; the wireless resonant rings (10) are arranged in an array, and every two adjacent wireless resonant rings (10) are coupled to each other; the wireless resonant rings (10) are used for receiving magnetic resonance signals; the plurality of wireless resonant rings (10) are arranged on the flexible substrate (20); and the flexible substrate (20) is configured to be fitted to the oral area. The unique brace-shaped structure is closely fitted to the oral anatomical structure, has high sensitivity, enables simultaneous imaging of upper and lower dentitions, realizes full-mouth scan and greatly simplifies the process. The coil exhibits an ultra-high resolution and an excellent signal-to-noise ratio, can accurately capture dental crowns, root canals and periodontal tissues, and provides excellent soft tissue contrast. The compact and highly adaptable design of the coil takes into account both the comfort and diversified needs of patients.

Description

Braces-shaped magnetic resonance oral wireless coil, magnetic resonance imaging equipment Technical Field

[0001] This application belongs to the field of magnetic resonance imaging technology, specifically, it relates to a brace-shaped magnetic resonance oral wireless coil and a magnetic resonance imaging device. Background Technology

[0002] Magnetic resonance imaging (MRI) is becoming a revolutionary alternative to traditional X-ray imaging techniques such as cone-beam computed tomography (CBCT). While CBCT has long dominated dental clinics due to its excellent hard tissue imaging capabilities, its dependence on ionizing radiation and limited soft tissue contrast have gradually revealed some limitations. These limitations have spurred the exploration of MRI applications in dental imaging, especially driven by its advantages in soft tissue contrast and radiation-free imaging, providing a new perspective for oral diagnosis. In MRI, signal acquisition includes two phases: radiofrequency excitation and radiofrequency reception. During the excitation phase, the MRI system sends radiofrequency signals to the oral cavity region through a transmitting coil, exciting hydrogen nuclei; during the reception phase, the signals released by the hydrogen nuclei are captured by a receiving coil and fed back to the imaging system. The performance of the receiving coil directly affects image quality.

[0003] The main problems with coil design in current oral MRI technology lie in insufficient sensitivity, signal interference, and a lack of optimization for oral anatomy. The primary challenge in oral MRI technology is designing specially optimized receiving coils to meet the unique imaging needs of the oral cavity. Compared to general-purpose coils used in the head and neck or other areas, oral coils require customized designs specifically for the small, high-density, and complex anatomical structures of the oral cavity. First, the imaging targets in the oral cavity (such as teeth, roots, periodontal tissues, and pulp) are densely distributed with significant anatomical interfaces, requiring coils to efficiently capture weak signals and provide high-resolution imaging. High sensitivity is crucial because the target area within the oral cavity is small and the signal is weak; traditional head and neck coils often fail to provide sufficient signal sensitivity due to design limitations, leading to reduced image resolution. Second, oral imaging typically requires high spatial adaptability because the complex structure of the oral cavity (such as tooth arrangement and hard-soft tissue junctions) requires coils to accurately cover the target area while avoiding signal loss or occlusion of the imaging area. However, existing general-purpose head and neck coil designs typically fail to consider these unique anatomical features, resulting in deficiencies in sensitivity, signal-to-noise ratio, and spatial adaptability during oral imaging, thus affecting image quality. Analysis reveals the following main shortcomings in current oral MRI coil designs:

[0004] 1) Existing oral imaging typically uses head-neck coils as receiving coils. Traditional commercial head-neck coils are usually kept at a certain distance from the oral cavity area, resulting in a significant decrease in signal acquisition sensitivity, especially for signals from deep areas such as the dental pulp and periodontal tissues. The coil design is mainly focused on large-area uniform imaging, and its number of turns and wire distribution are not optimized for small-area targets, thus failing to achieve optimal performance in localized imaging such as the oral cavity. In addition, the signals from the cheek, buccal fat pad, and lips are usually stronger than those from the teeth and root regions, and head-neck coils cannot effectively isolate these interfering signals, leading to a decrease in the signal-to-noise ratio of the target area. Furthermore, there are also external and internal receiving coils. External coils fit snugly against the lips, but their imaging depth is insufficient. While internal coils provide better imaging results than external coils, they pose safety risks due to heat generation.

[0005] 2) Existing oral imaging uses surface coils. Surface coils have insufficient adaptability; their rigid design makes it difficult to fully conform to complex oral anatomy structures, such as the curvature of the dentition and spatial differences between the upper and lower jaws. Surface coils are usually single-layer designs, with limited sensing range, making it difficult to cover multiple tooth areas simultaneously, especially in patients with wide dental arches, where signal loss may occur.

[0006] 3) Existing oral imaging techniques utilize small local coils. Small coils offer significantly improved sensitivity due to their extremely close proximity to the target area, but their coverage is limited, making it difficult to image the entire dentition in a single scan. Their sensing area is typically 3-5 cm, requiring multiple repositioning scans, which increases the complexity of the examination and patient discomfort.

[0007] To address these challenges, oral MRI technology urgently needs a new coil design that can improve the signal-to-noise ratio of imaging for delicate oral structures such as periodontal tissues and dental pulp, while also enhancing the ability to receive signals from deep tissues, and taking into account the flexibility of the coil and the comfort of the patient. Summary of the Invention

[0008] The technical problem addressed by this application is: how to provide a magnetic resonance oral wireless coil that can improve the imaging effect in the oral cavity area, and also enhance the flexibility of the coil and the comfort of the patient.

[0009] This application provides a brace-shaped magnetic resonance oral wireless coil, the magnetic resonance oral wireless coil comprising:

[0010] Several wireless resonant rings, each of which is a flexible loop structure, are arranged in an array and adjacent wireless resonant rings are coupled together, and the wireless resonant rings are used to receive magnetic resonance signals.

[0011] A flexible substrate, wherein a plurality of the wireless resonant rings are disposed on the flexible substrate, the flexible substrate being used to attach to the oral cavity region.

[0012] Optionally, the wireless resonant loop includes:

[0013] A flexible conductive circuit, wherein the flexible conductive circuit is a closed-loop structure;

[0014] A resonant circuit, the resonant circuit including a first capacitor;

[0015] A detuned circuit, the detuned circuit comprising a second capacitor and an inductor.

[0016] Optionally, the detuned circuit also includes two diodes.

[0017] Optionally, the coupling method of two adjacent wireless resonant rings is overlapping decoupling.

[0018] Optionally, adjacent wireless resonant rings are cross-stacked to achieve overlapping decoupling.

[0019] Optionally, the number of wireless resonant rings is at least four.

[0020] Optionally, the wireless resonant ring is detachably attached to the flexible substrate.

[0021] Optionally, each of the wireless resonant rings is arranged in a row with multiple columns.

[0022] This application also provides a magnetic resonance imaging device, which includes the above-mentioned brace-shaped magnetic resonance oral wireless coil and head array coil.

[0023] The present application provides a brace-shaped magnetic resonance oral wireless coil and magnetic resonance imaging device, which have the following technical advantages:

[0024] Its unique brace-shaped structure closely conforms to the oral anatomy, offering high sensitivity and enabling simultaneous imaging of the upper and lower dentition, achieving full-mouth scanning and significantly simplifying the process. The coil boasts ultra-high resolution and an excellent signal-to-noise ratio, accurately capturing crowns, root canals, and periodontal tissues, providing superior soft tissue contrast. Its compact and adaptable design caters to both patient comfort and diverse needs. Attached Figure Description

[0025] Figure 1 is a schematic diagram of a brace-shaped magnetic resonance oral wireless coil according to one or more embodiments;

[0026] Figure 2 is a schematic diagram of the arrangement of various wireless resonant rings according to one or more embodiments;

[0027] Figure 3 is a circuit schematic diagram of a wireless resonant ring according to one or more embodiments;

[0028] Figure 4 is a physical diagram of a dental wireless coil in the shape of a brace according to one or more embodiments;

[0029] Figure 5 is a schematic diagram of the operation and test results of a magnetic resonance imaging device according to one or more embodiments;

[0030] Figure 6 shows individual imaging of the head array coil according to one or more embodiments, as well as imaging of the magnetic resonance oral radionuclide coil and the head array coil in combination. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] Before describing the various embodiments of this application in detail, the technical concept of this application is first briefly described: Currently, when performing magnetic resonance imaging (MRI) of the oral cavity, traditional commercial head and neck coils are typically used to image the oral cavity area, or surface coils are used. This approach is difficult to achieve good imaging of the oral cavity area, and it is also difficult to match the shape of the oral cavity, making it difficult to obtain a complete imaging signal. Furthermore, the comfort and flexibility of wearing the coil are poor. Therefore, this application provides a brace-shaped MRI oral wireless coil and an MRI imaging device. Several flexible wireless resonant rings are disposed on a flexible substrate. The shape of the flexible substrate can be flexibly adjusted as needed and then fitted to the oral cavity area. The wireless resonant rings are used to receive magnetic resonance signals. This MRI oral wireless coil can better adapt to and cover the shape of the oral cavity area, and at a closer distance, it can obtain higher quality imaging and is more comfortable to wear. The specific principles of the brace-shaped MRI oral wireless coil and its usage method are described below with reference to more embodiments.

[0033] Specifically, as shown in Figures 1, 2, and 3, the brace-shaped magnetic resonance oral wireless coil of this embodiment includes several wireless resonant rings 10 and a flexible substrate 20. Each wireless resonant ring 10 is a flexible loop structure, and the wireless resonant rings 10 are arranged in an array with adjacent wireless resonant rings 10 coupled. The wireless resonant rings 10 are used to receive magnetic resonance signals. The several wireless resonant rings 10 are disposed on the flexible substrate 20, which is used to attach to the oral cavity area. The magnetic resonance oral wireless coil adopts a flexible design, improving the deep imaging of the oral anatomy. It fits closely to the teeth, located between the teeth and lips, without affecting tongue movement, thus ensuring patient comfort. The wireless resonant rings 10 can be directly attached to the areas where signal enhancement is needed, eliminating the need for cables and RF connectors, simplifying the usage process and improving the patient experience.

[0034] In one or more embodiments, the wireless resonant ring 10 includes a flexible conductive loop 11, a resonant circuit 12, and a detuning loop 13. The flexible conductive loop 11 is a closed-loop structure. The resonant circuit 12 includes a first capacitor, and the detuning loop 13 includes a second capacitor and an inductor. The tuning of the wireless resonant ring 10 is achieved through the first capacitor C1 in the resonant circuit, and the frequency of the detuning loop is achieved by adjusting the second capacitor C2 and the inductor L1. Each wireless resonant ring 10 is precisely tuned to a predetermined resonant frequency, which enhances the intensity of the B1- field without interfering with the B1+ field. This achieves high signal-to-noise ratio imaging of delicate oral structures such as periodontal tissues and dental pulp. The wireless resonant ring enables local signal enhancement of specific areas, significantly improving the imaging effect of deep oral structures (such as tooth roots and jawbones).

[0035] For example, the detuned circuit 13 also includes two diodes for controlling the on or off state of the detuned circuit, so that the magnetic resonance oral radio coil and the head array coil can be effectively coordinated. The diodes are PIN diodes.

[0036] In one or more embodiments, the coupling method of two adjacent wireless resonant rings 10 is overlapping decoupling. Exemplarily, two adjacent wireless resonant rings are cross-overlapped to achieve overlapping decoupling. For example, the overlap ratio of two adjacent wireless resonant rings is set to 10%, without limiting the overlap area or overlap angle.

[0037] In one or more embodiments, as shown in FIG4, the number of wireless resonant rings 10 is at least four, that is, the magnetic resonance oral wireless coil is a four-channel coil. Exemplarily, the wireless resonant rings 10 are arranged in a row and multiple columns, that is, the wireless resonant rings 10 are arranged in a straight line, which can adapt to the shape of the oral cavity.

[0038] The wireless resonant ring 10 is detachably attached to the flexible substrate 20 to facilitate adjustment of the number of wireless resonant rings 10 according to the size of the oral cavity, ensuring optimal imaging effect and wide coverage. Exemplarily, each wireless resonant ring 10 has a flexible support layer 14 underneath, which can support the flexible conductive circuit 11, the resonant circuit 12, and the detuning circuit 13, while also facilitating the attachment of the flexible support layer 14 to the flexible substrate 20. Each wireless resonant ring 10 is an independent module with a detachable design, and multiple resonant rings can be stacked to form a signal enhancement array, providing scalability. The independent module design reduces equipment failure rate and improves maintenance convenience. It can be dynamically combined with any commercial coil (including head / chest / limb coils) and can also achieve signal amplification function through a plug-and-play approach.

[0039] In one or more embodiments, the magnetic resonance imaging device includes the aforementioned brace-shaped magnetic resonance oral wireless coil and head array coil. The operation of the magnetic resonance imaging device is described below:

[0040] As shown in Figure 5, when the head coil (4WTC) is operating in the transmitting phase, the de-resonant module in the wireless resonant loop 10 (Head Coil 48channel) and the PIN diode in the RF module of the array coil are turned on, keeping the entire loop in a de-resonant state to prevent the RF signal from breaking down the circuit. When the array coil is operating in the receiving phase, the de-resonant module in the wireless resonant loop and the PIN diode in the RF module of the array coil are turned off, allowing the signal to pass through. To prevent common-mode current from being generated in the loop, each coil's coaxial cable has a notch filter circuit resonating at the same Larmor frequency to reduce common-mode current. The signal then passes through the notch filter circuit to the phase shifter loop. To reduce insertion loss after module cascading, a π-type or T-type phase shifter is used. The phase shifter changes the phase of the signal received from the coil to the phase set by the magnetic resonance system. The signal is amplified by an amplifier, and then transmitted through the bed to a computer for signal post-processing to complete image reconstruction. According to the test results and as shown in Figure 6, the wireless resonant ring 10 improves the signal-to-noise ratio of the image by more than 6.8 times within a certain range, thereby improving the signal-to-noise ratio and image quality, enhancing the imaging effect of periodontal tissues and pulp, and facilitating subsequent diagnosis by doctors.

[0041] The brace-shaped wireless MRI coil for the oral cavity provided in this embodiment has the following advantages: Firstly, for complex or deep oral structures requiring specialized imaging, the coil's adaptability is optimized to closely conform to the oral anatomy, ensuring sufficient imaging depth in the target area. Secondly, the wireless resonant ring enhances the signal-to-noise ratio near the subcutaneous region, significantly improving the signal-to-noise ratio for both upper and lower teeth. Furthermore, the four-channel intraoral coil is compatible with commercially available head coils. Beyond technological innovation, this brace-shaped wireless coil also provides a cost-effective and multifunctional solution for clinical applications. Its compact and adaptable design not only reduces manufacturing costs but also ensures compatibility with various anatomical variations, making it suitable for diverse oral imaging needs.

[0042] The specific embodiments of this application have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and improvements can be made to these embodiments without departing from the principles and spirit of this application as defined by the claims and their equivalents, and such modifications and improvements should also be within the protection scope of this application.

Claims

1. A brace-shaped magnetic resonance oral wireless coil, wherein, The magnetic resonance oral wireless coil includes: Several wireless resonant rings, each of which is a flexible loop structure, are arranged in an array and adjacent wireless resonant rings are coupled together, and the wireless resonant rings are used to receive magnetic resonance signals. A flexible substrate, wherein a plurality of the wireless resonant rings are disposed on the flexible substrate, the flexible substrate being used to attach to the oral cavity region.

2. The brace-shaped magnetic resonance oral wireless coil according to claim 1, wherein, The wireless resonant loop includes: A flexible conductive circuit, wherein the flexible conductive circuit is a closed-loop structure; A resonant circuit, the resonant circuit including a first capacitor; A detuned circuit, the detuned circuit comprising a second capacitor and an inductor.

3. The brace-shaped magnetic resonance oral wireless coil according to claim 2, wherein, The detuned circuit also includes two diodes.

4. The brace-shaped magnetic resonance oral wireless coil according to claim 1, wherein, The coupling method of two adjacent wireless resonant rings is overlapping decoupling.

5. The brace-shaped magnetic resonance oral wireless coil according to claim 4, wherein, The two adjacent wireless resonant rings are cross-stacked to achieve overlapping decoupling.

6. The brace-shaped magnetic resonance oral wireless coil according to claim 1, wherein, The number of wireless resonant rings is at least four.

7. The brace-shaped magnetic resonance oral wireless coil according to claim 1, wherein, The wireless resonant ring is detachably attached to the flexible substrate.

8. The brace-shaped magnetic resonance oral wireless coil according to claim 1, wherein, Each of the aforementioned wireless resonant rings is arranged in a row with multiple columns.

9. A magnetic resonance imaging device, wherein, The magnetic resonance imaging device includes a brace-shaped magnetic resonance oral wireless coil and a head array coil as described in claim 1.

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