High-speed signal transmission scheme for MRI receiving array probe: non-magnetic ultra-fine coaxial cable

In the MRI (magnetic resonance imaging) system, the extremely fine coaxial cables of the receiving array probe play a crucial role in transmitting the weak radio frequency signals generated by human tissue to the host side. Since MRI is extremely sensitive to the magnetic field environment, the cables must completely avoid magnetic materials to ensure imaging quality and system stability. Scientific cable material selection and design are the foundation for MRI systems to achieve high-resolution and high signal-to-noise ratio imaging.

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Why do we need non-magnetic materials?

The core of MRI lies in strong magnetic fields and precise radio frequency signals. The presence of magnetic impurities in the cables can lead to magnetic field distortion, local artifacts, and signal interference, severely affecting image quality. Especially in multi-channel receiving arrays, dense wiring increases the risk of crosstalk. Therefore, extremely thin coaxial cables must be designed non-magnetic in a thorough manner to ensure the complete transmission of radio frequency signals and the stable operation of the MRI system.

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Common non-magnetic materials in ultra-fine coaxial cables

In the aspect of conductors, high-purity oxygen-free copper, beryllium copper, and aluminum alloys are commonly used choices, which ensure both conductive performance and avoid magnetic interference. The shielding and outer layer usually adopt non-magnetic silver-plated copper braided mesh, non-magnetic metal foil, as well as PTFE, PEEK, or polyimide as supporting materials, taking into account the shielding effect and structural stability. The insulation and dielectric layer use PTFE, polyimide, or foam materials to achieve low loss and impedance matching. Connectors and junctions strictly avoid ferromagnetic parts, using non-magnetic stainless steel, beryllium copper, or gold-plated, silver-plated materials to ensure long-term reliable connections.

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Challenges and Design Points in Applications

With the development of 3T, 7T and higher field strength MRI, the requirements for non-magnetic design are becoming more stringent. The dense cable layout requires reasonable arrangement to reduce crosstalk, while maintaining flexibility and shielding integrity to meet the bending requirements in the narrow space inside the probe. Some cutting-edge solutions attempt to digitize the analog signal at the probe end and transmit it through optical fibers to further reduce the interference caused by analog cables, achieving higher precision imaging.

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The extremely fine coaxial cables for the probe array of MRI receivers, with non-magnetic materials, precise shielding, and high reliability design, provide a stable radio frequency signal transmission guarantee for high-field MRI systems. Every link, whether conductor, shielding, insulation, or connector, needs to be strictly controlled. With the development of multi-channel array and high-field MRI, the design of non-magnetic cables will become the core element to ensure imaging accuracy and system stability.

I am[Suzhou Huichengyuan Electronic Technology], long-term focus on the design and customization of high-speed signal cables and ultra-thin coaxial cables. For customization or technical consultation, welcome to contactManager Zhang: 18913228573 (same as WeChat)。