Brace-shaped magnetic resonance oral cavity wireless coil and magnetic resonance imaging equipment

Abstract

The invention provides a brace-shaped magnetic resonance oral cavity wireless coil and magnetic resonance imaging equipment. The magnetic resonance oral cavity wireless coil comprises a plurality of wireless resonant rings and a flexible substrate, each wireless resonant ring is of a flexible loop structure, the wireless resonant rings are arranged in an array mode, every two adjacent wireless resonant rings are coupled, the wireless resonant rings are used for receiving magnetic resonance signals, the wireless resonant rings are arranged on the flexible substrate, and the flexible substrate is arranged on the flexible substrate. The flexible substrate is used for being attached to an oral cavity area. The unique tooth socket-shaped structure is tightly attached to oral anatomy, the sensitivity is high, upper and lower dentitions can be imaged at the same time, full-oral scanning is achieved, the process is greatly simplified, the coil has ultrahigh resolution and excellent signal-to-noise ratio, dental crowns, root canals and periodontal tissues can be accurately captured, and excellent soft tissue contrast is provided. The compact and high-adaptability design gives consideration to the comfort and diversified requirements of the patient.

Description

Technical Field

[0001] This application belongs to the field of magnetic resonance imaging technology. Specifically, it relates to a magnetic resonance oral wireless coil in the shape of a dental appliance and a magnetic resonance imaging device. Background Art

[0002] Magnetic resonance imaging (MRI) technology is becoming a revolutionary alternative to traditional X-ray imaging technologies such as cone beam computed tomography (CBCT). Although CBCT has long dominated dental clinics due to its excellent hard tissue imaging ability, it has gradually revealed some limitations due to its dependence on ionizing radiation and limited soft tissue contrast. These limitations have prompted the exploration of the application of MRI technology in dental imaging. Especially driven by the advantages of soft tissue contrast and radiation-free imaging, MRI provides a new perspective for oral diagnosis. During the MRI process, signal acquisition includes two stages: radiofrequency excitation and radiofrequency reception. In the radiofrequency excitation stage, the MRI system sends radiofrequency signals to the oral region through a transmit coil to excite hydrogen nuclei; in the reception stage, the signals released by the hydrogen nuclei are captured by a receive coil and fed back to the imaging system. The performance of the receive coil directly affects the image quality.

[0003] The main problems in coil design in existing oral MRI technologies lie in insufficient sensitivity, signal interference, and the lack of optimized design for oral anatomical features. The primary challenge in oral MRI technology is to design a specially optimized receive coil to meet the unique imaging requirements of the oral region. Compared with general coils for the head and neck or other parts, oral coils need to be customized specifically for the small-scale, high-density, and complex anatomical structures in the oral cavity. First, the imaging targets in the oral region (such as teeth, tooth roots, periodontal tissues, and dental pulp) are densely distributed and have significant anatomical interfaces, which requires the coil to be able to efficiently capture weak signals and provide high-resolution imaging. High sensitivity is crucial because the target areas in the oral cavity are small and the signals are weak, and traditional head and neck coils often cannot provide sufficient signal sensitivity due to design limitations, resulting in reduced image resolution. Second, oral region imaging usually requires high spatial adaptability because the complex structures in the oral cavity (such as tooth arrangement, the junction of hard and soft tissues, etc.) require the coil to accurately cover the target area while avoiding signal loss or imaging area occlusion. However, the existing general head and neck coil designs usually do not take into account these unique anatomical features. Therefore, when performing oral imaging, there are deficiencies in sensitivity, signal-to-noise ratio, and spatial adaptability, thus affecting the improvement of image quality. After analysis, the main deficiencies in the coil design of current oral MRI technologies are as follows:

[0004] 1) Existing oral imaging usually uses a head and neck coil as a receiving coil. Traditional commercial head and neck coils usually maintain a certain distance from the oral area, resulting in a significant decrease in signal acquisition sensitivity, especially for signals in deep areas such as the pulp and periodontal tissue. The design of the coil is mainly centered on large-scale uniform imaging, and its number of turns and wire distribution are not optimized for small-scale targets, so it cannot perform optimally in local imaging such as the oral cavity. In addition, the signals of the cheeks, buccal fat pads, and lips are usually stronger than those of the teeth and root areas, and the head and neck coil cannot effectively isolate these interfering signals, resulting in a decrease in the imaging signal-to-noise ratio of the target area; in addition, the receiving coil also has an extraoral coil and an intraoral coil. The extraoral coil fits the lips, but the imaging depth is insufficient. Although the intraoral coil has better imaging effects than the extraoral coil, it has safety hazards due to heat generation.

[0005] 2) Existing oral imaging uses surface coils. The adaptability of surface coils is insufficient, and their rigid design makes it difficult to fully fit the complex oral anatomical structure, such as the curved shape of the dentition and the spatial difference 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 at the same time, especially in patients with wide dental arches, where signal loss may occur.

[0006] 3) Existing oral imaging attempts use small local coils. Small coils are very close to the target area, so their sensitivity is greatly improved, but their coverage is small, making it difficult to image the entire dentition at one time. Their sensing area is usually 3-5 cm, and they need to be moved multiple times for scanning, which increases the complexity of the examination and the discomfort of the patient.

[0007] In response to the above challenges, oral MRI technology urgently needs a new coil design that can not only improve the imaging signal-to-noise ratio of delicate oral structures such as periodontal tissue and dental pulp, but also improve the signal reception capability of deep tissues while taking into account the flexibility of the coil and the comfort of the patient. Summary of the invention

[0008] The technical problem solved by the present application is: how to provide a magnetic resonance oral wireless coil that can improve the imaging effect of the oral area and improve the flexibility of the coil and the comfort of the patient.

[0009] The present application provides a dental braces-shaped magnetic resonance oral wireless coil, the magnetic resonance oral wireless coil comprising:

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

[0011] A flexible substrate, a plurality of the wireless resonant rings are arranged on the flexible substrate, and the flexible substrate is used to be attached to the oral region.

[0012] Optionally, the wireless resonant loop includes:

[0013] A flexible conductive loop, the flexible conductive loop being a closed-loop structure;

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

[0015] A detuning loop, the detuning loop including a second capacitor and an inductor.

[0016] Optionally, the detuning loop further includes two diodes.

[0017] Optionally, the coupling manner between two adjacent wireless resonant loops is overlapping decoupling.

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

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

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

[0021] Optionally, the arrangement manner of each wireless resonant loop is an arrangement of multiple columns in one row.

[0022] This application further provides a magnetic resonance imaging device, the magnetic resonance imaging device including the above-mentioned dental braces-shaped magnetic resonance oral wireless coil and a head array coil.

[0023] A dental braces-shaped magnetic resonance oral wireless coil and a magnetic resonance imaging device provided by this application have the following technical effects:

[0024] The unique dental braces-shaped structure closely fits the oral anatomy, has high sensitivity, can image the upper and lower dental arches simultaneously, realizes full-mouth scanning and greatly simplifies the process. The coil has ultra-high resolution and excellent signal-to-noise ratio, can accurately capture the dental crown, root canal and periodontal tissue, provides excellent soft tissue contrast, and its compact and adaptable design takes into account patient comfort and diverse needs. Description of the Drawings

[0025] Figure 1 Schematic diagram of a dental braces-shaped magnetic resonance oral wireless coil according to one or more embodiments;

[0026] Figure 2 Arrangement schematic diagram of each wireless resonant loop according to one or more embodiments;

[0027] Figure 3 Circuit schematic diagram of a wireless resonant loop according to one or more embodiments;

[0028] Figure 4 Physical diagram of a dental brace-shaped magnetic resonance oral wireless coil according to one or more embodiments;

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

[0030] Figure 6 Separate imaging diagram of a head array coil and imaging diagram of the cooperation between the magnetic resonance oral wireless coil and the head array coil according to one or more embodiments. Detailed implementation manners

[0031] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] Before describing the various embodiments of the present application in detail, the technical concept of the present application will be briefly described first: Currently, when performing magnetic resonance imaging on the oral cavity, a traditional commercial head and neck coil is usually used to image the oral cavity area or a surface coil is set. On the one hand, it is difficult to obtain good imaging of the oral cavity area. On the other hand, it is also difficult to match the shape of the oral cavity, and it is difficult to obtain a complete imaging signal, and the wearing comfort and use flexibility are poor. For this reason, the present application provides a dental brace-shaped magnetic resonance oral wireless coil and a magnetic resonance imaging device. A number of flexible wireless resonant rings are arranged on a flexible substrate. After flexibly adjusting the shape of the flexible substrate according to needs, it is attached to the oral cavity area. The wireless resonant rings are used to receive magnetic resonance signals. This magnetic resonance oral wireless coil can better adapt to and cover the oral cavity shape area, and the distance is closer, so higher-quality imaging can be obtained and the wearing effect is more comfortable. The specific principle of the dental brace-shaped magnetic resonance oral wireless coil and its usage method of the present application will be described below with more embodiments.

[0033] Specifically, as Figure 1 、 Figure 2 、 Figure 3As shown, the dental braces-shaped magnetic resonance oral wireless coil of the first embodiment includes a plurality of wireless resonant loops 10 and a flexible substrate 20. Each wireless resonant loop 10 is a flexible loop structure. The wireless resonant loops 10 are arranged in an array and adjacent two wireless resonant loops 10 are coupled. The wireless resonant loops 10 are used to receive magnetic resonance signals. The plurality of wireless resonant loops 10 are arranged on the flexible substrate 20, and the flexible substrate 20 is used to adhere to the oral cavity area. Among them, the magnetic resonance oral wireless coil adopts a flexible design, which improves the deep imaging of oral anatomical structures, closely adheres to the teeth, is located between the teeth and the lips, does not affect the movement of the tongue, and takes into account the comfort of patients. The wireless resonant loops 10 can be directly adhered to the place where the signal needs to be enhanced. There are no cables and RF connectors, which simplifies the use process and improves the patient experience.

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

[0035] Exemplarily, the detuning circuit 13 further includes two diodes, which are used to control the conduction or shutdown of the detuning circuit, so that the magnetic resonance oral wireless coil can effectively cooperate with the head array coil. Among them, the diode adopts a PIN-type diode.

[0036] In one or more embodiments, the coupling method between adjacent two wireless resonant loops 10 is overlapping decoupling. Exemplarily, adjacent two wireless resonant loops are cross-overlapped to achieve overlapping decoupling. For example, the cross-overlapping ratio between adjacent two wireless resonant loops is set to ten percent, and the overlapping area and overlapping angle are not limited.

[0037] In one or more embodiments, as Figure 4 shown, the number of the wireless resonant loops 10 is at least four, that is, the magnetic resonance oral wireless coil is a four-channel coil. Exemplarily, the arrangement method of each wireless resonant loop 10 is an arrangement of one row and multiple columns, that is, each wireless resonant loop 10 is arranged in a straight line, which can adapt to the shape of the oral cavity.

[0038] The wireless resonant loop 10 is detachably attached to the flexible substrate 20 to facilitate adjusting the number of wireless resonant loops 10 according to the size of the oral cavity, ensuring the best imaging effect and having a wide coverage range. Exemplarily, a flexible bearing layer 14 is provided below each wireless resonant loop 10, which can bear the flexible conductive loop 11, the resonant circuit 12, and the detuning loop 13, and also facilitates attaching the flexible bearing layer 14 to the flexible substrate 20. Each wireless resonant loop 10 is an independent module and adopts a detachable design. Multiple resonant loops can be stacked to form a signal enhancement array, which has scalability. The independent module design reduces the device failure rate and improves the maintenance convenience. It can be dynamically combined with any commercial coil (including head / chest / limb coils), and the signal amplification function can also be achieved through a plug-and-play method.

[0039] In one or more embodiments, the magnetic resonance imaging device includes the above-mentioned dental brace-shaped magnetic resonance oral wireless coil and the head array coil. The working process of the magnetic resonance imaging device is described as follows:

[0040] As Figure 5 shown, when the head array coil (4WTC) operates in the transmission stage, the detuning module in the wireless resonant loop 10 (Head Coil48channel) and the PIN diode in the RF module of the array coil are turned on, making the entire loop in a detuned state to prevent the RF signal from breaking down the circuit; when the array coil operates in the reception stage, the detuning 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 the generation of common-mode current in the loop, a notch filter circuit resonating at the same Larmor frequency is provided on the coaxial cable of each coil to reduce the common-mode current. Then the signal passes through the notch filter circuit to the phase shifter loop; to reduce the insertion loss after module cascading, the phase shifter adopts a π-type phase shifter or a T-type phase shifter. The function of the phase shifter is to change the phase of the signal received from the coil to the phase set by the magnetic resonance system. The signal passes through the amplifier to amplify the weak magnetic resonance voltage signal received from the coil, and is transmitted to the computer through the hospital bed for signal post-processing to complete the reconstruction of the image. According to the test results, and combined with Figure 6 shown, the wireless resonant loop 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 of the image, enhancing the imaging effect of the periodontal tissue and the pulp part, and facilitating the subsequent diagnosis by doctors.

[0041] The magnetic resonance oral wireless coil in the shape of a dental appliance provided in this embodiment has the following effects: For the complex or deep structures in the oral cavity that require special imaging, first, the adaptability of the oral coil is optimized to closely adhere to the oral anatomy to ensure the imaging depth of the target area; second, the wireless resonance ring will enhance the signal-to-noise ratio near the subcutaneous position, and the signal-to-noise ratio of the upper and lower tooth tissues is significantly improved. Moreover, the four-channel intraoral coil is universal for commercial head coils. In addition to technological innovation, this wireless dental appliance-shaped coil also provides an economical and efficient multi-functional solution for clinical applications. Its compact structure and strong adaptability design not only reduce the manufacturing cost but also ensure compatibility with various anatomical variations, making it suitable for various oral imaging needs.

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

Claims

1. A dental braces-shaped oral magnetic resonance wireless coil, characterized in that: The magnetic resonance oral wireless coil comprises: A plurality of wireless resonant rings, each of which is a flexible loop structure, each of which is arranged in an array and two adjacent wireless resonant rings are coupled, and the wireless resonant rings are used to receive magnetic resonance signals; A flexible substrate, a plurality of the wireless resonant rings are arranged on the flexible substrate, and the flexible substrate is used to be attached to the oral region.

2. The dental braces-shaped oral magnetic resonance wireless coil according to claim 1, characterized in that: The wireless resonant ring comprises: A flexible conductive loop, wherein the flexible conductive loop is a closed loop structure; a resonant circuit, the resonant circuit comprising a first capacitor; A detuning circuit includes a second capacitor and an inductor.

3. The dental brace-shaped oral magnetic resonance wireless coil according to claim 2, characterized in that: The detuning loop further includes two diodes.

4. The dental braces-shaped oral magnetic resonance wireless coil according to claim 1, characterized in that: The coupling mode of two adjacent wireless resonant rings is overlapping decoupling.

5. The dental braces-shaped oral magnetic resonance wireless coil according to claim 4, characterized in that: Two adjacent wireless resonant rings are cross-stacked to achieve overlapping decoupling.

6. The dental braces-shaped oral magnetic resonance wireless coil according to claim 1, characterized in that: The number of the wireless resonant rings is at least four.

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

8. The dental brace-shaped oral magnetic resonance wireless coil according to claim 1, characterized in that: The wireless resonant rings are arranged in a row and multiple columns.

9. A magnetic resonance imaging device, characterized in that: The magnetic resonance imaging device comprises the dental braces-shaped oral magnetic resonance wireless coil and a head array coil as claimed in any one of claims 1 to 8.

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