Measurement of amygdala T2 relaxation time in temporal lobe epilepsy
- MRI Unit, National Society for Epilepsy, Chalfont St Peter, Buckinghamshire, UK, and Department of Clinical and Experimental Epilepsy, Institute of Neurology, London, UK
- Correspondence to: Professor J S Duncan, National Society for Epilepsy, Chalfont St Peter, Buckinghamshire SL9 0RJ, UK; j.duncan{at}ion.ucl.ac.uk
- Received 17 May 2002
- Accepted 21 August 2002
- Revised 12 August 2002
Abstract
Objectives: To implement and validate the use of coronal dual echo T2 maps for the measurement of T2 relaxation time of the amygdala (AT2) as a rapid and reproducible method for identifying amygdala abnormality.
Methods: 20 healthy subjects and 25 patients with known hippocampal sclerosis (HS) were studied using a dual echo CSE sequence on a 1.5T MRI GE scanner. The T2 relaxation time of the amygdala was calculated and measured using a previously validated method.
Results: The mean control AT2 was 88.1 ms (SD 2 ms). The coefficient of reliability was good at 6.3% test-retest and 7.4% inter-rater. The upper limit of normal AT2 was 92 ms. AT2 was abnormal ipsilaterally in six, and bilaterally in three, of 20 patients with unilateral HS. Two of five patients with bilateral HS had unilateral abnormal AT2.
Conclusion: Reliable T2 measurements can be obtained in the amygdala, and may be useful in the detection of amygdala abnormality.
