Transmit/receive radiofrequency coil with individually shielded elements
Corresponding Author
Kyle M. Gilbert
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Robarts Research Institute, The University of Western Ontario, PO Box 5015, 100 Perth Drive, London, Ontario, Canada N6A 5K8===Search for more papers by this authorAndrew T. Curtis
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada N6A 5C1
Search for more papers by this authorJoseph S. Gati
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorL. Martyn Klassen
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorLauren E. Villemaire
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorRavi S. Menon
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada N6A 5C1
Search for more papers by this authorCorresponding Author
Kyle M. Gilbert
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Robarts Research Institute, The University of Western Ontario, PO Box 5015, 100 Perth Drive, London, Ontario, Canada N6A 5K8===Search for more papers by this authorAndrew T. Curtis
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada N6A 5C1
Search for more papers by this authorJoseph S. Gati
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorL. Martyn Klassen
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorLauren E. Villemaire
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Search for more papers by this authorRavi S. Menon
Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada N6A 5K8
Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada N6A 5C1
Search for more papers by this authorAbstract
A novel method for decoupling coil elements of transmit/receive (transceive) arrays is reported. Each element of a coil array is shielded both concentrically and radially to reduce the magnetic flux linkage between neighboring coils; this substantially reduces the mutual inductance between coil elements and allows them to behave independently. A six-channel transceive coil was developed using this decoupling scheme and compared with two conventional decoupling schemes: the partial overlapping of adjacent elements and capacitive decoupling. The radiofrequency coils were designed to image the human head and were tested on a 7-T Varian scanner. The decoupling, transmit uniformity, transmit efficiency, signal-to-noise ratio, and geometry factors were compared between coils. The individually shielded coil achieved higher minimum isolation between elements (2.7–4.0 dB) and lower geometry factors (2–14%) than the overlapped and capacitively decoupled coils, while showing a reduction in transmit efficiency (2.8–5.9 dB) and signal-to-noise ratio (up to 34%). No difference was found in the power absorbed by the sample during a 90° radiofrequency pulse. The inset distance of coil elements within their shields was then reduced, resulting in significant improvement of the transmit efficiency (1.3 dB) and signal-to-noise ratio (28%). The greatest asset of this decoupling method lies in its versatility: transceive coils can be created with elements of arbitrary shape, size, location, and resonant frequency to produce three-dimensional conformal arrays. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc.
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