The Application Of FDG-PET/MRI Coregistration In The Presurgical Evaluation Of Drug-resistant Focal Epilepsy

Background and objective:FDG-PET is one of the important presurgical evaluation in drug-resistant focal epilepsy which can improve ratio of the epileptogenic zone detection.But because of its own limitation, the epileptogenic zone’s detection rate of separate FDG-PET is not high, epileptogenic zone’s positioning accuracy is not high. But through the use of FDG-PET/MRI coregistration, epileptogenic zone’s detection rate and positioning accuracy will be greatly improved. This experiment based on the contrast analysis, comparing the two methods,exploring the application of FDG-PET/MRI coregistration in the presurgical evaluation of drug-resistant focal epilepsy.Methods:This study included the refractory focal epilepsy patients who received treatment in the epilepsy center of the second affiliated hospital of medical school, zhejiang university from February 2014 to December 2015.All patients in this study do the long-range video electroencephalogram (VEEG) monitoring, the ordinary head MRI scan, high-resolution MRI of thin T1WI layer scanning which can be rebuilt into 3D images and other high-resolution MRI sequence, fluorine-18 fluorodeoxyglucose positron emission tomography. According to the result of ordinary head MRI, refractory focal epilepsy patients would be divided into lesional groups, subtle-lesional group and nonlesional group. Making use of Analyze 11.0 to rebuilt high-resolution MRI of thin T1WI layer scanning and fluorine-18 fluorodeoxyglucose positron emission tomography to 3D image model, and then turn the two images into the same direction.After that, using SPM8 to make the coregistration of FDG-PET images and MRI image. Do qualitative visual analysis of FDG-PET/MRI coregistration image, find abnormal metabolism zone and the potential epileptogenic zone, then comparing the result of electroclinical epilepsy hypothesis zone the consistency and the FDG-PET/MRI coregistration result to analysis the consistency, exploring the application of FDG-PET/MRI coregistration in the presurgical evaluation of drug-resistant focal epilepsy.Results:The study included 97 patients, electricity-clinical assumptions of temporal lobe epilepsy are 44 cases, extemporal lobe epilepsy are 47 cases,5 cases only canbe located in hemisphere,1 case unable to be located.According to the report of FDG-PET,consistent with electrioclinical assumptions,the consistent rate was 45.4%; FDG-PET/MRI coregistration results,consistent with electrioclinical assumptions,the consistent rate was 85.6%(P<0.01). There were 31 people undergo surgery, including 30 cases were lobotomy or lesions resection,1 case was palliative surgery:vagus nerve stimulation. Lesional groups had 66.7% FDG-PET result consistent with electrioclinical assumptions;subtle-lesional group had 58.5% FDG-PET result consistent with electrioclinical assumptions (P<0.01);nonlesional group had 32% FDG-PET result consistent with electrioclinical assumptions (P<0.01).Lesional groups had 83.8% FDG-PET/MRI coregistration result consistent with electrioclinical assumptions;subtle-lesional group had 92.7% FDG-PET/MRI coregistration result consistent with electrioclinical assumptions;nonlesional group had 80% FDG-PET/MRI coregistration result consistent with electrioclinical assumptions.Conclusion:FDG-PET/MRI fusion compared with separately FDG-PET, not only can improve the discovery rate of metabolic abnormalities in refractory focal epilepsy, but also can improve its consistency with electroclinical assumptions. This study find that in each subgroup,FDG-PET/MRI fusion result’s abnormal metabolism of positive rate is very high (83.3%-100%), and FDG-PET/MRI fusion results consistent with electro-clinical assumptions rate is also high (80%-92.7%). These results consistent with electro-clinical assumptions directly promote a lot of people undergo epilepsy surgery, the most significant FDG-PET/MRI fusion analysis result is that in subtle-lesional group and nonlesional group who undergo surgery(30 cases)was found abnormal structure of the brain in their MRI before by the help of FDG-PET which consistent with electro-clinical assumptions in refractory focal epilepsy, change the patient’s clinical decision, prompting the poor control epilepsy patients to good control through epilepsy surgery or at least can relieve the bad effects of epilepsy.