High resolution in vivo imaging at high frequences with improved surface coils

Proceedings of: 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Amsterdam, 31 Oct. - 03 Nov. 1996.The enhancement of the spatial resolution with an optimised surface coil design for MR imaging of small structures at high frequencies is presented. Surface coils provide high signal-to-noise ratios (SNR) which allow to improve the spatial resolution. However, their sensitivity is limited to the region adjacent to the coil where the B1 field distribution is more homogeneous. The authors present an inductively coupled series-tuned circular coil prototype, optimised for 1H MR imaging at 200 MHz. The inductively coupled scheme provides a good SNR by reducing the different losses mechanisms. Preliminary images, acquired on a Bruker BIOSPEC-BMT 47/40 working at 4.7 T, have been realised over a rabbit knee. Images depict a high spatial resolution, an excellent B1 field homogeneity and no `hot spots'Publicad