Magnetic Resonance Diffusion Tensor Imaging Studies In Epilepsy

Objective: This study aims to evaluate whether the parameters obtained from magnetic resonance diffusion tensor imaging(DTI) are associated with epileptic course and its efficacy, and explore whether there are some imaging indications reflecting the epileptic activity and course.Methods: 52 patients with definite epilepsy were enrolled from October 2012 to December 2014 in North Sichuan Medical College. The patients were grouped by the course of disease and the effect on treatment respectively. The former was grouped into short-course group(seizure history<1 year) and long-course group(seizure history≥1 year). The latter was grouped into good effect group(no seizure in 3 months before MRI scanning) and poor effect group(one or more seizures in 3 months before MRI scanning). All patients were received a 3.0 T MRI scanning which were run on both general sequence and DTI sequence. The areas of interest at frontal lobe、temporal lobe、hippocampus and Corpus callosum were selected, and the data from these areas of interest were imported to the Advanced Workstation and AW4.4 post-processing workstation, which was provided by GE, for processing and calculation. The ADC, FA, VR and RC values were abstracted from each area of interest, and the correlation between these parameters and the epileptic course, as well as the efficacy were analyzed. All data were run on the SPSS13.0 software and the independent samples t test was used, with P <0.05 as significant differences and statistical significance.Results:Compared with the short-course group(﹤1year), the values of ADC in the long-course( ≥1year) group at frontal lobe, temporal lobe and hippocampus were increased, and the differences attached the significant levels(P<0.05);the values of FA at frontal lobe and temporal lobe were statistically reduced(P<0.05), but no significant difference was found at hippocampus; the values of VR at frontal lobe, temporal lobe and hippocampus had no significant difference; the values of RA decreased at frontal lobe and temporal lobe with significant difference(P<0.05), but no statistical difference was found at hippocampus; the volume of Corpus callosum decreased significantly(P<0.05).Comared with the good effect group((no seizure in 3 months before MRI scanning), the values of ADC in the poor effect group(one or more seizures in 3 months before MRI scanning) at temporal lobe and hippocampus increased significantly(P<0.05), but the difference at frontal lobe was not obvious; the values of FA, VR and RA, and the volumes of Corpus callosum had no significant differences between the two groups.Conclusion:(1) The epileptic patients with longer history of seizures have less Corpus callosum volume, higher ADC values at frontal lobe, temporal lobe and hippocampus, lower FA values at frontal lobe and temporal lobe than epileptic patients with shorter history of seizures. This suggests that the epileptic patients with longer history might have more obvious changes of microstructure and physiology and biochemistry.(2) The history of seizures may have a positive correlation with the ADC value, negative correlation with the FA value and the Corpus callosum volume, but no correlation with the VR value.(3) A higher ADC value at temporal lobe and hippocampus might be an imaging indication of active epilepsy or poorer effect, whereas, the FA and RA value, and the Corpus callosum volume might be insensitive in reflecting the epileptic activity and the therapeutic effect.