A four-channel small-volume wireless coil and its application device
Patent Information
- Application Number
- CN202521988520.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2026-09-01
- Estimated Expiration
- 2035-09-16
AI Technical Summary
缺点：电缆可能限制患者舒适度或操作灵活性，体积庞大、布线复杂，尤其不适合小体积、高分辨率的成像场景
该设计具有以下关键技术创新：
Smart Images
Figure CN224708619U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of magnetic resonance imaging technology, specifically, this application relates to a four-channel small-volume wireless coil and its application device. Background Technology
[0002] High-resolution magnetic resonance imaging (MRI) plays an increasingly crucial role in visualizing finger structures, particularly in the early diagnosis and monitoring of joint diseases such as rheumatoid arthritis, psoriatic arthritis, and osteoarthritis. The metacarpophalangeal joint (MCP joint) between the proximal phalanges and metacarpals is a clinically significant area, often the initial site of early lesions. Clearly displaying the minute anatomical structures of this joint requires extremely high spatial resolution and signal-to-noise ratio (SNR), which current routine clinical MRI equipment struggles to meet. Existing clinical MRI examinations typically use general-purpose hand or wrist phased array coils. While these coils are suitable for overall anatomical imaging, their large spatial coverage makes it difficult to focus on a single finger, resulting in insufficient SNR and limited image resolution. To date, there is no clinically dedicated MRI coil specifically designed for single-finger imaging, which to some extent limits the early diagnostic capability of small joint lesions.
[0003] Current MRI coil designs can be broadly categorized into two types: 1. A wired coil, connected to the MRI system via a physical cable, transmits radio frequency signals; Advantages: Stable signal transmission, suitable for high-precision imaging, with high SNR and parallel imaging capabilities; Disadvantages: Cables may limit patient comfort or operational flexibility; they are bulky and complex to install, making them particularly unsuitable for small-volume, high-resolution imaging scenarios. Application scenarios: Commonly used in traditional MRI equipment, such as head coils, torso coils, and limb coils. Wired traditional phased array coils have high SNR and parallel imaging capabilities, but they are bulky, have complex wiring, and poor flexibility, making them particularly unsuitable for small-volume, high-resolution imaging scenarios.
[0004] 2. Wireless coil: Utilizes wireless radio frequency transmission technology to communicate with the MRI system; Advantages: Reduces cable interference, improves patient comfort and ease of operation.
[0005] Disadvantages: It typically suffers from problems such as using system coils, like birdcage coils, to receive images, lack of parallel imaging support, and poor small joint imaging space performance.
[0006] Application scenarios: New MRI equipment, especially when flexible movement or multi-channel imaging is required; Inductive wireless passive resonant coils improve patient comfort and placement flexibility by eliminating cables, but they usually have problems such as using a system body coil (birdcage coil) to receive images, lack of parallel imaging support, and poor small joint imaging space performance.
[0007] Furthermore, magnetic resonance coils typically employ either volumetric arrays (for field uniformity) or surface arrays (for local sensitivity). However, in small, anatomically complex MCP joint imaging, both types of structures have significant limitations: volumetric arrays cannot achieve sufficient proximity and focusing, while surface arrays face limitations in coverage angle and penetration depth.
[0008] It is particularly important to note that, due to the tapered narrowing and asymmetrical anatomical structure of the finger at the MCP joint, traditional volumetric cylindrical coil structures (i.e., typical volumetric coil designs) struggle to conform to the curved surface of this region, resulting in low signal-to-noise ratio and insufficient imaging capabilities, severely limiting their application in high-resolution imaging of the MCP joint. Using surface coils alone also fails to overcome problems such as insufficient angular coverage and uneven signal reception. Utility Model Content
[0009] This invention proposes a four-channel small-volume wireless coil and application device, which integrates volumetric array and surface array technology to achieve high-resolution MRI imaging of the entire finger—especially the geometrically complex MCP joint region. Through near-field coupling and cooperation with the magnetic resonance system's volumetric coil, the signal-to-noise ratio of the finger region imaging is improved, ensuring patient comfort and system safety.
[0010] To achieve the above objectives, the present invention adopts the following technical solution: A four-channel small-volume wireless coil, the coil comprising: a coil substrate, which is made of a flexible planar material that is a flexible and magnetically resonant compatible electrical insulating material, for attaching and fixing the coil; The wireless coil comprises four sets of basic coil units arranged in a cylindrical structure, namely the first basic coil unit, the second basic coil unit, the third basic coil unit and the fourth basic coil unit. Each set of basic coil units is arranged in a partially overlapping manner, with adjacent sets arranged in the same direction and crossing each other, and two sets arranged in opposite directions with a gap of two sets and two sets of cross capacitors connected in series. The crossing or overlapping are mutually insulated. The basic coil unit includes a rectangular coil formed by two sets of capacitors connected in series. The two sets of capacitors are arranged in parallel on the basic coil. One set of capacitors on the basic coil unit is connected in parallel to another set of capacitors, which is a decoupling circuit composed of an inductor L and two anti-parallel PIN diodes V connected in series. The two ends of the other set of capacitors are respectively connected to the crossover capacitors.
[0011] The wireless coil is composed of a volumetric array coil pattern and a surface array coil pattern. The volumetric array coil pattern is formed by stacking and surrounding basic coil units one after the other to form a volumetric cavity. The volumetric array coil pattern includes a decoupling circuit and a capacitor. The surface array coil pattern is a planar structure composed of single or adjacent basic coil units partially continuous conductor bundles that extend out of the volumetric cavity in a parallel, opposite or umbrella-like manner.
[0012] Furthermore, the decoupling circuit capacitor terminal of the first base coil unit overlaps with the decoupling circuit capacitor terminal of the second base coil unit, the decoupling circuit capacitor terminal of the second base coil unit overlaps with the decoupling circuit capacitor terminal of the third base coil unit, and the decoupling circuit capacitor terminal of the third base coil unit overlaps with the decoupling circuit capacitor terminal of the fourth base coil unit, and the decoupling circuit capacitor terminals of the first base coil unit and the fourth base coil unit are connected end to end.
[0013] Decoupling between adjacent base coil units is achieved through partial overlap; decoupling between non-adjacent base coil units is accomplished through the intermediate base coil unit itself or any adjacent base coil unit decoupling network circuit.
[0014] The geometric design is tailored for the single-finger structure. The basic coil unit is arranged into a regular q or p-shaped coil with a rectangular shape. The first, second, third and fourth basic coil units are arranged in the qpqp direction.
[0015] On the other hand, this application provides a four-channel small-volume wireless coil application device, including: a main magnetic field generator for generating a main magnetic field passing through the imaging area; a radio frequency exciter for applying a radio frequency pulse of a certain frequency to the subject to be imaged; and a signal receiver and an imaging display device, wherein the imaging area is covered by a wireless radio frequency coil, and the radio frequency pulse magnetic field signal emitted by the radio frequency exciter is converted into a converted signal by the coil decoupling circuit, and the converted signal is then received by the signal receiver for display imaging.
[0016] As can be seen from the above technical solution, this utility model has the following advantages: This design features the following key technological innovations: 1. The four-channel wireless phased array structure can work in conjunction with conventional clinical head coils and has excellent parallel imaging capabilities. 2. A hybrid structure design that combines the advantages of volume and surface array achieves overall finger fit and improves local SNR; 3. A simple yet efficient decoupling method that avoids the instability caused by complex active decoupling circuits; 4. Fully compatible with existing MRI hardware and software platforms, requiring no modifications to the scanning system, and can be used simultaneously with wired coils or other wireless coils; 5. A geometric design tailored to the structure of a single finger ensures precise coverage and high-definition imaging of the MCP joint area.
[0017] This hybrid wireless coil represents a technological breakthrough in the field of small-volume MRI imaging hardware. By overcoming the bottlenecks of existing coil structures in terms of geometric fit, signal-to-noise ratio, and parallel processing capabilities, this system promises to provide a new clinical solution for rapid, high-resolution imaging of small finger joints, while significantly improving image quality, spatial specificity, and operational flexibility. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the circuit layout of this utility model; Figure 2 This is a schematic diagram of the structure of this utility model. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.
[0020] like Figure 1 The present invention discloses a four-channel small-volume wireless coil, the coil comprising: a coil substrate, which is made of a flexible planar material that is a flexible and magnetically resonant compatible electrical insulating material for attaching and fixing the coil; The wireless coil comprises four sets of basic coil units arranged in a cylindrical structure, namely the first basic coil unit 1, the second basic coil unit 2, the third basic coil unit 3 and the fourth basic coil unit 4. Each set of basic coil units is arranged in a partially overlapping manner, with adjacent sets arranged in the same direction and crossing each other, and two sets arranged in opposite directions with a gap of two sets and two sets of cross capacitors connected in series. The crossing or overlapping are mutually insulated. The basic coil unit includes a rectangular coil formed by two sets of capacitors connected in series. The two sets of capacitors are arranged in parallel on the basic coil. One set of capacitors on the basic coil unit is connected in parallel to another set of capacitors, which is a decoupling circuit composed of an inductor L and two anti-parallel PIN diodes V connected in series. The two ends of the other set of capacitors are respectively connected to the crossover capacitors.
[0021] Furthermore, the terminal of the first basic coil unit 1 away from the decoupling circuit capacitor overlaps with the terminal of the second basic coil unit 2 away from the decoupling circuit capacitor; the terminal of the second basic coil unit 2 away from the decoupling circuit capacitor overlaps with the terminal of the third basic coil unit 3 away from the decoupling circuit capacitor; the terminal of the third basic coil unit 3 away from the decoupling circuit capacitor overlaps with the terminal of the fourth basic coil unit 4 away from the decoupling circuit capacitor; and the terminals of the first basic coil unit 1 and the fourth basic coil unit 4 are connected end to end.
[0022] Decoupling between adjacent basic coil units (1-2, 2-3, 3-4, 4-1) is achieved through partial overlap; decoupling between non-adjacent basic coil units (1–3, 2–4) is accomplished through the intermediate basic coil unit itself or any adjacent basic coil unit (2-2, 2-3) decoupling network circuit. Example
[0023] like Figure 2 The geometric design shown is tailored for a single-finger structure. The basic coil unit is arranged into a regular q or p-shaped coil with a rectangular shape. The first basic coil unit 1, the second basic coil unit 2, the third basic coil unit 3 and the fourth basic coil unit 4 are arranged in the qpqp direction.
[0024] The surface array coil pattern consists of a planar structure composed of single or adjacent basic coil units and continuous conductor bundles extending out of the volume cavity in a parallel, opposite, or umbrella-like manner. After shaping, a cylindrical coil with a pair of notches is formed and placed on a single finger, with the notches ending between the fingers, forming a volumetric array coil pattern, including a decoupling circuit 5 and a capacitor 7; the first, second, third, and fourth basic coil units, with continuous copper traces 6 attached to the epoxy board 9 at their intersections and overlaps, form a planar structure that extends parallel to each other out of the volumetric cavity, with the coils extending to the palm and back of the hand, forming a surface array coil pattern. Any group of basic coil units at the intersections or overlaps is connected and insulated by enameled wire 8; thus, a hybrid structure design combining volumetric and surface arrays is achieved, resulting in overall finger fit and improved local SNR.
[0025] Coil applications:
[0026] The application scenarios for fingers also include: a main magnetic field generator for generating a main magnetic field that passes through the imaging area; a radio frequency exciter for applying radio frequency pulses of a certain frequency to the subject to be imaged; and a signal receiver and an imaging display device, wherein the area to be imaged covers a wireless radio frequency coil of the hand, and the radio frequency pulse magnetic field signal emitted by the radio frequency exciter is converted into a converted signal by the coil decoupling circuit, and the converted signal is then received and displayed by the signal receiver.
[0027] This hybrid structure design approach, which combines the advantages of volumetric and / or surface arrays, can also be used for: 1. Head coil top cover design; 2. Abdominal prostate wireless coil; 3. Shoulder coil; 4. Invasive prostate and cervical wireless coil.
[0028] Furthermore, multi-channel phased array coil technology plays a crucial role in improving the signal-to-noise ratio and shortening scan time in magnetic resonance imaging. However, for imaging small anatomical sites, conventional wired coils present significant challenges in designing and wiring within small dimensions, making small-volume wireless coil technology a uniquely advantageous approach.
[0029] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A four-channel, small-volume wireless coil, the coil comprising: The coil substrate is a flexible planar material made of a flexible, magnetically resonant, electrically insulating material, used for attaching and fixing the coil. The wireless coil comprises four sets of basic coil units arranged in a cylindrical structure, namely the first basic coil unit, the second basic coil unit, the third basic coil unit and the fourth basic coil unit. Each set of basic coil units is arranged in a partially overlapping manner, with adjacent sets arranged in the same direction and crossing each other, and two sets arranged in opposite directions with a gap of two sets and two sets of cross capacitors connected in series. The crossing or overlapping are mutually insulated. The basic coil unit includes a rectangular coil formed by two sets of capacitors connected in series, and the two sets of capacitors are arranged in parallel on the basic coil. One set of capacitors on the basic coil unit is connected in parallel to another set of capacitors, which is a decoupling circuit composed of an inductor L and two anti-parallel PIN diodes V connected in series. The two ends of the other set of capacitors are respectively connected to the crossover capacitors. The wireless coil is composed of a volumetric array coil pattern and a surface array coil pattern. The volumetric array coil pattern is formed by stacking and surrounding the basic coil units one after the other to form a volumetric cavity. The volumetric array coil pattern includes a decoupling circuit and a capacitor. The surface array coil pattern consists of a planar structure composed of single or adjacent basic coil unit portions of continuous conductor bundles extending out of the volume cavity in a parallel, opposite, or umbrella-like manner.
2. The four-channel small-volume wireless coil according to claim 1, characterized in that, The decoupling circuit capacitor terminal of the first basic coil unit overlaps with the decoupling circuit capacitor terminal of the second basic coil unit, the decoupling circuit capacitor terminal of the second basic coil unit overlaps with the decoupling circuit capacitor terminal of the third basic coil unit, and the decoupling circuit capacitor terminal of the third basic coil unit overlaps with the decoupling circuit capacitor terminal of the fourth basic coil unit. The decoupling circuit capacitor terminals of the first and fourth basic coil units are connected end to end. Decoupling between adjacent base coil units is achieved through partial overlap; decoupling between non-adjacent base coil units is accomplished through the intermediate base coil unit itself or any adjacent base coil unit decoupling network circuit.
3. A four-channel small-volume wireless coil according to claim 1 or 2, characterized in that, The basic coil units are arranged in a regular q or p shape, similar to a rectangular shape, and the first, second, third and fourth basic coil units are arranged in the qpqp direction.
4. A device for applying a four-channel small-volume wireless coil as described in claim 1 or 2, comprising: The main magnetic field generator is used to generate the main magnetic field that passes through the imaging region; Radio frequency exciter, used to apply radio frequency pulses of a certain frequency to the object to be imaged; And a signal receiver and an imaging display device, characterized in that: The area to be imaged is covered by a wireless radio frequency coil. The radio frequency pulse magnetic field signal emitted by the radio frequency exciter is converted into a signal by the coil decoupling circuit. The converted signal is then received by the signal receiver for display and imaging.