J Korean Soc Magn Reson Med.  2009 Dec;13(2):171-176.

The Effect of Coating Material of Copper-wire RF Coil on the Signal-to-Noise Ratio in MR Images

• Lee H
• Moon H
• Chang Y
• Hong KS

Abstract

PURPOSE
To investigate the effect of coating material in RF coil, which is one of main parts in MRI machine, on the Q-factor and SNR(signal-to-noise ratio) in MR images.
MATERIALS AND METHODS
RF coils with inner diameter of 1.7 mm were made by using copper wires coated with polyester, polyurethane, polyimide, polyamideimide, and polyester-imide, and by using copper wires in which coating materials had been removed. Q-factors of the RF coils were measured by network analyzer, and SNR values in the spin-echo MR images obtained by 600 MHz (14.1 T, Bruker DMX600) micro-imaging system for the coated and uncoated cases.
RESULTS
The measured SNRs were almost same for the RF coils with coat-removed copper wires, however SNRs and Q-factors were different for the coated cases depending on the coating material. They were maximized in the polyurethane-coated case in which the SNR was >30% greater than polyester-coated case.
CONCLUSION
We made solenoid-type RF coils which were easily used for MR micro-imaging in Bruker MRI probe. There was a significant coating-material dependence in the measured Q values and SNRs for the home-made RF coils. The study demonstrated that the choice of coating material of RF coil may be a critical factor in the MRI sensitivity based on SNR value.

Keyword

MRI; RF coil; Coating material; SNR

MeSH Terms

Copper
Polyesters
Polyurethanes
Signal-To-Noise Ratio
Copper
Polyesters
Polyurethanes