Meeting Banner
Abstract #2774

Inverse Field-Based Approach for the Evaluation of Electromagnetic Fields and Its Application in Local SNR Shimming

Jin Jin1, Feng Liu1, Ewald Weber1, Stuart Crozier1

1The School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia

The substantial challenges for high-field magnetic resonance imaging are the control of transmit magnetic field (B1+) homogeneity and the specific absorption rate (SAR), so that the potential for higher signal-to-noise ratio (SNR) at high fields can be realised. To address these challenges, we demonstrate the use of the inverse field-based approach for simultaneous mapping of the magnetic and the concomitant electric field distributions within the imaged subject. Using a simple yet effective RF shimming algorithm, dubbed SNR shimming, the complete knowledge of the electromagnetic field distribution enables us to more effectively regulate B1-inhomogeneity, maximum local SAR and local SNR.

Abstract PDF E-Poster Video

Keywords

accompanying accuracy achieved actual agreement applied array arrive ascertain away better body bond built challenge chosen circles circularly coil column columns components conductivity controlling corrected counterparts degree delays density derived described desired developed deviations directly distribution distributions dividing driving effective effectively electric electrical electromagnetic employed employing energy enhancing errors estimations evaluation exited experimental experimentally extended extracted field fields finds focusing font full future gradient graph homogeneity house improvement indicated indicates inevitably inhomogeneity intensity introduced inverse iterative known local localized location mapping mappings maps matching minimization minimized models namely naturally newly noise nominal numerical obtainable obvious optimal optimization pair phantom placed polynomial potential power procedure process produces proportional proposed proton pulsed quantities read receive receptivity rectangular reducing regulate regulated respectively resultant saline sample school searches shimming slice specifically spin steady stemmed stopping studies subject surface system term text traditional transmission transmit tuned utilizing validation variables voltage volunteers wave weber whereas whole yields