Magma (New York, N.Y.) · 2011
Stripline resonator and preamplifier for preclinical magnetic resonance imaging at 4.7 T.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод в очереди
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Lavdas Ioannis, Seton Hugh C, Harrington Charles R, Wischik Claude M
Аннотация
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 B1 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.
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 B1 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.