3- NMR RF coils

Small animal array coil: In the field of small animal, modeling methods are applied to the development of array coils for High spatial Resolution MR Imaging (HR-MRI) of the articular cartilage (rat, monkey) and functional MRI (fMRI) in the rat brain. Due to limited size of small animal joints, cartilage assessment is very challenging. A two-channel phased array coil considerably improving the SNR as well as the signal uniformity was designed rat knee joint imaging at 7T. These parameters are mandatory to segment and to quantify cartilage morphology (thickness, volume). The spatial resolution value achieved with this coil has never been reported in the literature. An original four-channel coil based on common conductor decoupling technique was design for the simultaneous acquisition of the both knee joints of a rat. This coil constituted the first four-channel coil based on common conductor decoupling method not using local preamplifiers. Spatial resolution values are similar to values obtained with the two-channel coil with the additional advantage of acquiring both joints simultaneously thus significantly increasing throughput. The common conductor decoupling technique is also used to design a four-channel coil dedicate to the fMRI of rat brain. This coil improves exploration of deep areas of rat brain that are difficult to measure with fMRI techniques.