Electromagnetic characterisation of MR RF coils using the transmission-line modelling method |
| |
| Authors: | P J Cassidy S Grieve K Clarke D J Edwards |
| |
| Affiliation: | (1) British Heart Foundation Molecular Cardiology Group, Department of Biochemistry, University of Oxford, South Parks Road, OXI 3QU Oxford, UK;(2) Communicaiions Group, Department of Engineering Science, University of Oxford, Parks Road, 0X1 3PJ Oxford, UK |
| |
| Abstract: | The Transmission-Line Modelling (TLM) method is applied to the electromagnetic characterisation of RF coils and samples for
magnetic resonance imaging ()MRI. Theoretical verification was performed using a simple surface coil. Experimental verification
was performed using Alderman-Grant and birdcage coils constructed for use on a 7 T micro-imaging system. The modelling method
enabled electromagnetic characteristics of frequency response, electromagnetic field generation, energy stored and power loss
to be determined. From these parameters, coil resonant modes.B
1 field profiles, voltages, currents, quality factor (Q),π/2 pulse length, and the equivalent lumped-element circuit components of resistance, inductance and capacitance were calculated.
Equations are presented that enable a comprehensive electromagnetic characterisation of the RF coil and sample to be achieved
based on the results of the TLM simulations. The use of the TLM method is extended to include the design of safe arbitrary
multi-nuclear pulse sequences such that the specific absorption rate (SAR) of tissue, and RF coil component safety limits
are not exceeded. |
| |
| Keywords: | Radio-frequency coils Transmission-line modelling Electromagnetic simulation Specific absorption rate and magnetic resonance imaging |
| 本文献已被 SpringerLink 等数据库收录！ |
|
