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J Magn Reson Imaging · Nov 2008
Safety of localizing epilepsy monitoring intracranial electroencephalograph electrodes using MRI: radiofrequency-induced heating.
- David W Carmichael, John S Thornton, Roman Rodionov, Rachel Thornton, Andrew McEvoy, Philip J Allen, and Louis Lemieux.
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, and Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, Unit... more
- J Magn Reson Imaging. 2008 Nov 1;28(5):1233-44.
PurposeTo investigate heating during postimplantation localization of intracranial electroencephalograph (EEG) electrodes by MRI.Materials And MethodsA phantom patient with a realistic arrangement of electrodes was used to simulate tissue heating during MRI. Measurements were performed using 1.5 Tesla (T) and 3T MRI scanners, using head- and body-transmit RF-coils. Two electrode-lead configurations were assessed: a "standard" condition with external electrode-leads physically separated and a "fault" condition with all lead terminations electrically shorted.ResultsUsing a head-transmit-receive coil and a 2.4 W/kg head-average specific absorption rate (SAR) sequence, at 1.5T the maximum temperature change remained within safe limits (<1 degrees C). Under "standard" conditions, we observed greater heating (
ConclusionMRI for intracranial electrode localization can be performed safely at both 1.5T and 3T provided a head-transmit coil is used, electrode leads are separated, and scanner-reported SARs are limited as determined in advance for specific scanner models, RF coils and implant arrangements. Neglecting these restrictions may result in tissue injury.Copyright (c) 2008 Wiley-Liss, Inc. Notes