Design of a Four-Channel Surface Receiver Coil Array Without Preamplifiers for the Decoupling Between Elements: Validation for High-Resolution Rat Knee MR Imaging

In magnetic resonance imaging, multichannel coil arrays are increasingly being used to improve signal-to-noise ratio in order to increase spatial and/or temporal image resolution. A recent decoupling technique allows conception of two-channel surface transceiver coil arrays. This technique, based on a common conductor, does not require an additional preamplifier for the decoupling between elements. In this case, the coil array loops are directly connected to the independent transmit/receive switches and preamplifiers of the MR system. Using this common conductor decoupling technique, a topology of a four-channel coil array is developed and described in this paper. A four-channel surface receiver coil array is designed to perform the simultaneous acquisition of both rat knee joints at 7 T. Without the use of additional preamplifiers, a good decoupling between channels is obtained and very high spatial resolution 3-D images with a voxel size of 49 × 49 × 98 μm
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is achieved in 1 h 22 min scan time. Acquisitions allow the quantification of cartilage morphological parameters such as thickness and volume.