Concentric dual-loop RF coil for magnetic resonance imaging∗

A surface coil for MRI consisted of two concentric loops was developed to produce brain images with a commercial MR imager. Prior to build the coil prototype, the magnetic field (B1) generated by the coil was numerically simulated. This field simulation is based on the Biot-Savart law for the circularand square-shaped loop coils. From these theoretical results, we can appreciate an improvement on the B1 homogeneity. Comparison of experimental SNR for a single-loop and dual concentric figure coils show that the latter has better sensitivity and uniformity. Phantom and brain images were obtained on a 1.5 Tesla clinical imager, and showed a good image quality. These brain images when compared against images obtained with a circular-shaped coil exhibit a better capability of penetration. This receiver coil can generate high quality brain images. This coil design can be used in clinical imagers and is compatible with conventional imaging sequences and protocols.