Novel common-mode rejection balun structure for magnetic resonance radio frequency coil

Abstract

The invention discloses a novel common mode rejection balun structure for a magnetic resonance radio frequency coil. The structure comprises an upper layer structure, a middle layer structure and a lower layer structure, wherein the upper layer is a solenoid formed by winding a coaxial line, the middle layer is a hard printed circuit board, and the lower layer is a double-layer flexible printed circuit board; the double-layer flexible printed circuit board comprises a base material, an upper-layer conductor located on an upper surface of the base material and a lower-layer conductor located on a lower surface of the flexible base material; the upper-layer conductor and the lower-layer conductor are partially overlapped, and the overlapped upper-layer conductor, the overlapped lower-layer conductor and the base material between the upper-layer conductor and the lower-layer conductor form a planar flexible capacitor, shielding layers at two ends of the solenoid are respectively welded on the hard printed circuit board, and are connected in parallel with the planar flexible capacitor sequentially through the copper-clad layer conductor on the hard printed circuit board, the connecting wire conductor and the conductor on the flexible printed circuit board. According to the novel common-mode rejection balun structure for the magnetic resonance radio frequency coil, the size and the weight are obviously smaller than those of an existing common-mode rejection balun, frequency adjustment is very convenient, and the cost is lower.

Description

technical field [0001] The invention relates to a novel common mode suppression balun structure for magnetic resonance radio frequency coils. Background technique [0002] Magnetic resonance imaging is an advanced non-destructive imaging technology of the human body, which is widely used in the diagnosis of diseases in various parts of the human body. The magnetic resonance radio frequency coil is an important part of the magnetic resonance imaging system, and its performance directly determines the quality of the magnetic resonance imaging. [0003] The frequency of magnetic resonance signals is usually between tens of MHz and hundreds of MHz, and coaxial cables are usually used to transmit the signals. At the same time, because the electromagnetic environment in which the magnetic resonance radio frequency coil works is very complex, it is necessary to use a balun to suppress the common mode current on the coaxial line, otherwise the signal-to-noise ratio of the magnetic ...

AI Technical Summary

Problems solved by technology

However, the traditional common-mode suppression balun has a structure of a coaxial solenoid paralleled with ceramic capacitors. Since the solenoid needs to be wound and high-voltage ceramic capacitors need to be welded, its size is large, and usually requires Independent plastic shell protection, so it is usually big and thick

Moreover, since the current number of RF coil channels is increasing, there are more and more flexible RF coils with 16 channels, 32 channels or even 64 channels, and each channel requires at least one balun, so this traditional coaxial The balun structure wound into a solenoid can no longer meet the development needs of high-density flexible radio frequency coils, and has become a bottleneck factor that limits the further softness of flexible coils

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