Ultrahigh-field animal magnetic resonance radio frequency probe with high dielectric constant

Abstract

The invention relates to a high-dielectric-constant ultrahigh-field animal magnetic resonance radio frequency probe which comprises a coil unit, the coil unit comprises a cylindrical coil circuit substrate and a cylindrical inner wall substrate, and the inner wall substrate is arranged in the coil circuit substrate. The two ends of a high-dielectric-constant ceramic unit are fixed between the coilcircuit substrate and the coil inner wall substrate through a ceramic unit support. All the units are independent of one another, assembling is flexible, and the sensitivity of the radio frequency probe can be effectively improved. The plurality of high-dielectric-constant ceramic blocks can greatly improve the B1 field emission efficiency in the central region, and avoids the adverse effects ofcoil mode increase and disorder caused by complete cylindrical barium titanate ceramic.

Description

technical field [0001] The invention relates to the technical field of magnetic resonance imaging, in particular to a high dielectric constant ultra-high field animal magnetic resonance radio frequency probe. Background technique [0002] The radio frequency coil is at the front end of the magnetic resonance imaging (Magnetic Resonance Imaging, MRI) system, and has a decisive influence on the sensitivity of the MRI signal. MRI, B 1 Field (weak magnetic field caused by radio frequency pulse) uniformity and sensitivity are two extremely important indicators to measure the performance of radio frequency coils. The birdcage coil has good symmetry such that B 1 The field distribution is fairly uniform. Due to its sensitivity and B 1 The advantage of field uniformity has been widely used in various animal MRI experiments, and has become a very classic MR radio frequency body coil. [0003] In conventional research, improving the signal-to-noise ratio of birdcage coils with B ...

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Problems solved by technology

Adjust the shielding position by moving the shielding substrate, and then tune the coil ([3]DardzinskiB J, Li S, Collins C M, et al.A birdcage coil tuned by RF shielding for application at 9.4T[J].journal of magnetic resonance,1998, 131(1):32-38.) can improve the SNR and B to a certain extent 1 Field uniformity, but limited effect

Add end caps at both ends of the bird cage coil ([4]LouX, Gedney S D, Avison M J.End cap design for bird cage coils in nuclear magnetic resonance imaging[J].IEEE Transactions on Magnetics,1999,35(3):1939 -1946.) can increase the B near both ends of the coil 1 Field uniformity and sensitivity, but less noticeable effect on center position

[0007] Under the ultra-high field, due to the skin effect, the current density is unevenly distributed on the copper skin with a certain width, and it is mainly concentrated on the edge of the copper skin, which affects the B 1 Field uniformity; at the same time, the uneven current density distribution reduces the equivalent resistance, thereby reducing the B 1 field strength, leading to poor sensitivity

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