MRI Image Characteristics Of Temporal Lobe Epilepsy And Correlation With Surgical Treatment Prognosis

Objective(1)To explore the value of conventional MRI texture analysis in diagnosingtemporal lobe epilepsy due to hippocampal sclerosis.(2)To evaluate the value of ocalization diagnosis of MRI imaging texture analysis and18F-FDG PET in temporal lobe epilepsy patients with hippocampal sclerosis.(3)To evaluate the correlation between MRI temporal pole abnormalities(temporopolar blurring,TB and temporopolar atrophy,TA)and surgical treatment of prognosis in patients with temporal lobe epilepsy.Methods(1)The oblique coronal T2 FLAIR images of 22 patients with temporal lobe epilepsy and hippocampal sclerosis confirmed by pathology were analyzed by using Ma Zda software.The feature selection methods included mutual information(MI),Fishers coefficient and classification error probability combined with average correlation coefficients(POE+ACC)Through these methods,the texture features of hippocampus were extracted.Then,Four statistical methods were used to distinguish the hippocampal sclerosis side and normal side of the patients that were raw data analysis(Raw Date),the principal component analysis(PCA),linear discriminant analysis(LDA)and nonlinear discriminant analysis(NDA).The results are indicated with misclassification rate.Meanwhile,2 neuroradiologists also reviewed the MR images of 22 patients.The differences of the results between the two analysis methods were analyzed finally.(2)A retrospective study was carried out on 22 patients diagnosed with temporal lobe epilepsy due to hippocampal sclerosis.Conventional MRI, MRI texture analysis and 18F-FDG PET brain imaging were all acquired in these patients. Using pathological results as the gold standard, the accuracies of these three methods were compared.(3)Postoperative follow-up(1 to 2 years)was performed on 46 patients with postoperative pathology confirmed as the temporal lobe epileptic with hippocampal sclerosis.and they all performed a 3.0T MRI scan before surgery.There were two groups: temporopolar blurring(TB)and temporopolar atrophy(TA),according to the different imaging findings of MRI.A comparative study was conducted between thetwo groups according to the clinical manifestations,demography and postoperative follow-up results.Results(1)The misclassification rate was the lowest [4.55%(2/44)] via the FPM selection and NDA statistical method.Furthermore,There were statistically significant differences of the misclassification rate between the texture analysis and neuroradiologists’ analysis [25%(11/44)].(2)The accuracy rate of conventional MRI was 60%(13/22);The accuracy rate of conventional MRI combined with image texture analysis was 90%(20/22);The accuracy rate of conventional18F-FDG PET was 86.4%(19/22);Then further analysis was done by using the chi-square decomposition with the P value corrected to 0.05.As a result, we found the difference between conventional MRI and MRI combined with image texture analysis,18F-FDG PET imaging was statistically significant(χ2was 5.939,4.125, respectively and P= 0.017,P=0.044, respectively).The difference between MRI combined with image texture analysis and 18F-FDG PET was no statistically significant(χ2 was 0.226 and P=0.50).(3)Among the 46 patients with hippocampal sclerosis,there were 25 cases of TB and 22 cases of TA.The overlap rate between the two groups was higher(68%).There was no significant difference in the febrile convulsions,age of the epilepsy onset between the patients who with TB(or TA)signs and who without this sign.Intermittent epileptic discharge(IED)between there are TB sign and no such symptoms,there was no significant difference.People with TB(or TA)are older and have a longer history.Multiple logistic regression analysis showed that temporal pole abnormalities was related to the age of onset and age of surgery,and was not related to the surgical side.Conclusion(1)Texture analysis of conventional MRI can provide reliable objective basis for the diagnosis of temporal lobe epilepsy due to hippocampal sclerosis.(2)Conventional MRI scanning combined with image texture analysis has a high accuracy in the diagnosis of hippocampal sclerosis,and is close to18F-PDG PET results.MRI combined with image texture analysis can be used in the clinical diagnosis of epilepsy.18F-FDG PET test should be performed if the results from MRI combined with image texture analysis are inconclusive.(3)The temporal pole abnormalities(TB/TA)are frequent in patients with temporal lobe epilepsy due to hippocampal sclerosis,and may be related to the injuries caused by seizures.The study showed that there was no significant correlation between temporal pole abnormalities(TB/TA)and surgical treatment prognosis.