Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we will assume that you are happy to receive all cookies and you will not see this message again. Click 'Find out more' for information on how to change your cookie settings.

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, B1 field profiles, voltages, currents, quality factor (Q), pi/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.

Type

Journal article

Journal

MAGMA

Publication Date

03/2002

Volume

14

Pages

20 - 29

Keywords

Algorithms, Biophysical Phenomena, Biophysics, Electromagnetic Fields, Magnetic Resonance Imaging, Models, Statistical