Optimization of a parallel‐plate RF probe for high resolution thin film imaging. (27th December 2018)

• Record Type: Journal Article
• Authors: Ramírez Aguilera, Andrés; MacMillan, Bryce; Goward, Gillian R.; Balcom, Bruce J.
• Is Part Of: Concepts in magnetic resonance. Volume 47A:Number 1(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-12-27
• Subjects: lithium‐ion battery -- MRI -- optimization -- parallel‐plate resonator; Magnetic resonance -- Periodicals; Nuclear magnetic resonance -- Periodicals; 538
• DOI: 10.1002/cmr.a.21465
• Languages: English
• ISSNs: 1546-6086

Abstract

Abstract: Choosing an MR probe with the correct dimensions and high sensitivity is critical for magnetic resonance imaging, especially high resolution thin film imaging. In this work, a parallel‐plate resonator has been optimized for strength and uniformity of theB 1 magnetic field. The parallel‐plate resonator is designed for high resolution imaging in the direction perpendicular to the plates. The optimization process was undertaken through simulation with CST Micro Wave Studio, followed by experiment. A 400 μm capillary tube, filled with doped water, was used for testing the optimized probe in a 2.4 T magnet. It is shown that increasing the width of the copper leads connected to the plates increases the homogeneity of theB 1 magnetic field by almost 90%. The best approach to increase the sensitivity and the homogeneity of the probe was to maintain the dimensions of the plates and copper leads but to add additional capacitors at the corners to distribute the current. This approach produces a 40% strongerB 1 magnetic field and increases the homogeneity by almost 85%. The experimentalB 1 magnetic field of the parallel‐plate prototype agrees within 20% of the value found through simulation, for specified power. The experimental MRI results show that it is possible to achieve a nominal resolution of 10 μm between the plates for suitable samples using the optimized probe. The optimized parallel‐plate resonator, combined with a phase encode SE SPI method, may be used for high resolution studies of lithium‐ion transport in the electrolyte solution of lithium‐ion batteries.