Quantitative Study Of Temporal Lobe Epilepsy Based On MR Brain Structure Intelligence Analysis And DKI Technique

ObjectiveThrough MR quantitative scanning,we use the brain structure intelligent analysis system and diffusion kurtosis imaging to perform the macroscopic hippocampal volume measurements and quantitative analysis of the microstructure of temporal lobe white matter in patients with temporal lobe epilepsy(TLE).It will provide an imaging basis for early diagnosis and targeted treatment of the disease.The study consists of two parts:Part one:The MR brain structure intelligent analysis system and diffusion kurtosis imaging was applied to quantify TLE,to explore the diagnostic efficacy of the two methods alone and in combination,to screen for appropriate imaging biomarkers for early diagnosis of patients,and to promote the application of combined diagnostic techniques in the preoperative localization of TLE.Part two:Focusing on the sleep problems of TLE patients,we compared the differences in sleep scores between patients with sleep disorders and the healthy controls.We applied diffusion kurtosis imaging to assess the abnormalities of white matter microstructure in patients with combined sleep disorders,providing an imaging basis to facilitate individualized patient treatment.Part one1.Materials and methodsWe recruited fifty-eight patients with unilateral TLE(33 with L-TLE,25 with R-TLE)and thirty healthy controls.We used Siemens 3.0T MR scanner to capture 3D-T1WI and DKI images.Divided all subjects into four subgroups,L-HS(+),R-HS(+),HS(-),and the control group,according to the epileptic fixation side and whether hippocampal sclerosis(HS)was combined.Our study applied manual measurements as the gold standard to analyze the measurement errors of the brain segmentation technique.We measured the bilateral hippocampal volume and the volume asymmetry index(AI)through the brain segmentation technique.Furthermore,performed Intra-and inter-group comparisons of hippocampal volume and AI values were.A circular ROI with an area of not less than 25 mm~2was outlined in the white matter of the temporal lobe bilaterally on DKI images.Measurements were taken at the exact location in three consecutive levels of the mean kurtosis(MK),mean diffusivity(MD),and fractional anisotropy(FA)maps and the averaged as the final result.DKI parameters were compared within groups(affected vs.healthy)and between groups(affected vs.control)according to the epileptic side.Using ROC curves to assess the diagnostic efficacy of hippocampal volume,AI values,and DKI parameters independently and jointly.Differences in age,DKI parameters,and the hippocampal volume were compared using t-test,ANOVA.Non-parametric tests were used to compare differences in AI values,seizure duration.Quality control of the intelligent analysis system was performed using correlation(Pearson)and consistency analysis(Bland-Altman plot and intraclass correlation coefficient).2.ResultsThe ICC values of left and right hippocampal volumes obtained by the intelligent analysis system of brain structure and manual measurements were 0.884 and 0.900(P<0.05),respectively;the correlation coefficients were 0.893 and 0.906(P<0.05)respectively,and the measurement error of the analysis system was 3.4%.The hippocampal volumes reduced(P<0.05)on the affected side of TLE combined with HS,but there were no differences in HS(-)and the control groups(P>0.05).The overall differences in AI values and hippocampal volumes between the four subgroups were statistically significant(P<0.05).A post hoc pairwise comparisons revealed that the AI values in the L-HS(+)group were smaller than those in the R-HS(+)and the control groups(P<0.05),and also tended to be smaller than those in the HS(-)group(P>0.05).The AI values in the R-HS(+)group were larger than those in the HS(-),L-HS(+)and control groups(P<0.05).Patients had reduced MK and increased MD,which was significantly different in both intra-and inter-group comparisons,and significantly reduced FA in inter-group comparisons(P<0.05).Nevertheless,within-group differences have not been found in the MK,MD,FA for the controls,and FA for L-TLE(P>0.05).MK combined with AI the most significant area under the ROC curve for L-TLE diagnosis(AUC=0.933,critical value 0.50,sensitivity 85.19%,specificity 86.67%).The AI had the most significant area under the ROC curve for R-TLE diagnosis(AUC=0.937,critical value 0.06,sensitivity 75.00%,specificity 90.00%).3.Brief summaryThe MR brain structure intelligent analysis system has a measurement error within acceptable limits and can be utilized for volumetric measurements of TLE combined with HS.DKI can sensitively detect the white matter microstructural changes in TLE.The sensitivity of the MK is superior to FA and MD.The significance of MK in combination with AI values was tremendous in diagnosing L-TLE(AUC=0.933)and AI values in diagnosing R-TLE(AUC=0.937).MK and AI values can serve as crucial complementary information for visual assessment.Part two1.Materials and methodsWe included Forty-five patients with TLE and twenty-one healthy controls(excluding the first part aged>50 years).Sleep questionnaires were delivered to the subjects to assess their subjective sleep status and divided.According to the diagnostic criteria and scale scores,the patients were into two subgroups with and without sleep disorders.The differences in DKI parameters between the two subgroups were analyzed to explore microstructural abnormalities in patients with combined sleep disorders.Differences in sleep quality scores and DKI parameters were compared using t-test and ANOVA.Chi-square test or Fisher-Freeman-Halton test was applied to compare the count data.2.ResultsTLE combined with sleep disorders was common(66.67%in this study).All patients enrolled took a single antiepileptic drug except for four who were not taking medication.Levetiracetam had the highest use rate(51.22%)among the three antiepileptic drugs.The overall differences in ESS,PSQI,and AIS scores between patients with combined sleep disorders and the controls were statistically significant(P<0.05).The pairwise comparison revealed that the AIS and ESS scores of L/R-TLE and the PSQI scores of L-TLE were higher than those of the control group(P<0.05),and there was a tendency for the PSQI scores of the R-TLE to be greater than those of the control group(P>0.05).No statistical differences were found between patients with abnormal scores on the three scales.MK values were lower in patients with sleep disorders in L/R-TLE than in those without(P<0.05),and FA values also reduced in L-TLE with sleep disorders(P<0.05),but no differences were found in MD values or FA values in R-TLE(P>0.05).3.Brief summaryThe present study found abnormal DKI parameters in TLE combined with sleep disorders by quantitative analysis.We presumed the presence of abnormal white matter fiber structure in this type of patient.This finding could provide imaging data to support personalized treatment for patients with comorbidities,but further validation in subsequent studies is still needed.Conclusions(1)Combining the brain structure intelligent analysis system and diffusion kurtosis imaging allows for sensitive and accurate measurement of macroscopic and microscopic structural abnormalities in temporal lobe epilepsy.AI values were more sensitive than volumetric measurements alone in assessing asymmetries in hippocampal volumes.Kurtosis parameters(MK)are more susceptible to detecting differences in temporal lobe microstructure than tensor parameters(FA,MD).(2)The significance of MK in combination with AI values was most outstanding in diagnosing L-TLE(AUC=0.933)and AI values in diagnosing R-TLE(AUC=0.937).MK and AI values are recommended as new imaging biomarkers to provide important complementary information for the visual assessment of TLE.(3)Abnormal DKI parameters exist in patients with TLE combined with sleep disorders.Our research hypothesized that abnormal discharges in epilepsy and sleep comorbidities caused the abnormalities in this group together,which still needs further verification in future studies.