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Stripline resonator and preamplifier for preclinical magnetic resonance imaging at 4.7 T

Abstract

Object

To design and evaluate a fully shielded, λ/4 stripline resonator as a receive-only surface coil for preclinical MRI at 4.7 T.

Materials and methods

A 20 mm diameter stripline surface coil was fabricated from double-sided Duroid 5880 PCB material and was directly coupled to the input of a MOSFET preamplifier, without requiring a matching network. The new coil was compared with a conventional 20 mm, wire loop, receive-only surface coil in imaging experiments with a separate transmit-only saddle coil.

Results

The stripline surface coil exhibits a loaded Q-factor of 132 at 200 MHz, compared to 138 for a conventional wire loop coil and its resonant frequency drops by 0.2 MHz under loading, rather than 0.5 MHz for the wire loop. The stripline coil displays a more symmetrical B 1 map compared to the wire loop, but the SNR falls off more rapidly with depth so it is 30% poorer 8 mm from the coil plane. It should be possible, however, to reduce this difference by using a thicker dielectric in future versions of the stripline coil.

Conclusion

Compared to a conventional surface coil, the stripline coil is easy to manufacture, requires shorter set-up times and shows reduced dielectric interaction with conductive samples.

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Correspondence to Ioannis Lavdas.

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Lavdas, I., Seton, H.C., Harrington, C.R. et al. Stripline resonator and preamplifier for preclinical magnetic resonance imaging at 4.7 T. Magn Reson Mater Phy 24, 331–337 (2011). https://doi.org/10.1007/s10334-011-0273-8

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  • DOI: https://doi.org/10.1007/s10334-011-0273-8

Keywords

  • Preclinical MRI
  • Surface coil
  • Stripline resonator
  • High input impedance preamplifier
  • Electronic decoupling