Actively decoupled transmit-receive coil-pair for mouse brain MRI

A low-cost, high-performance RF coil-pair for MR imaging of mouse brain is described. A surface receiving coil is used for high spin-sensitivity, whereas a larger transmit coil, located outside the mouse holder, delivers good B ₁ uniformity across the brain with reasonable efficiency. The volume coil is constructed with an open architecture, making experimental setup easy and providing clear access to the head of the mouse. Each coil is switched between active and inactive modes using PIN diodes driven by a small amplifier external to the spectrometer. Because of this active decoupling, there is no requirement for orthogonal orientation of the coils. The coil pair is platform independent, requiring only a transmit/receive (T/R) signal to switch the amplifier that drives the PIN diodes and can therefore be used with virtually any commercial or homebuilt MR scanner.