RF Coils
The correct choice of the RF coil configuration for a given in-vivo investigation has an important impact on the quality of the results. In general, an RF coil configuration can contain one or several individual RF coils that form all together the RF coil configuration, i.e. the usage of separate RF coils for signal excitation and signal detection.
One might distinguish between two main types of RF coil configurations:
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- Transceiver coil configuration: signal excitation and signal detection are done with the same RF coil. The RF coil itself can be a volume or surface coil, single or double resonant. A synonym for transceiver coil is transmit/receive coil.
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- Cross coil configurations: signal excitation is done with a different RF coil than signal detection. In most cases, the excitation coil is a dedicated volume coil whereas the signal detecting coil is a small coil located as close as possible to the region of interest. The excitation coil in these coil configurations is optimized for a homogeneous excitation profile and coupling between the excitation coil and the receive coil is minimized. In this configuration, the excitation coil (transmit coil) may be a transmit-only or a transmit/receive coil with Active Detuning (AD). In the cross coil mode, a transmit/receive coil servers as transmit coil in combination with the separate receive-only coil used for signal detection. However, via ParaVision, the mode can be switched so that for certain applications, the transmit/receive coil can also be used for signal detection (TxRx Volume Coil Mode). In this case, the receive-only coil is although present in the magnet but not used for image acquisition.
Please remark that also mixtures of these two basic types can exist, i.e. coil configurations for pulsed arterial spin labeling or double resonance experiments.
Please refer to Chapter Animal Cradles and RF Coils for Mouse in vivo Applications, Animal Cradles and RF Coils for Rat in vivo Applications, Animal Cradles and RF Coils for Large Rodents and Materials for the selection of the best suited combination between RF coils and animal beds for various applications.
Further information