磁共振新序列影像技术在药物难治性眶额癫痫中的应用价值

Application value of new magnetic resonance sequences in drug-refractory orbitofrontal epilepsy

目的:探讨MRI新序列影像学技术在药物难治性眶额癫痫诊治中的应用价值。方法:回顾性分析2016年1月至2018年8月清华大学玉泉医院癫痫中心连续收治并经立体脑电图(SEEG)证实的4例药物难治性眶额癫痫患者的临床资料。术前分别采用MRI传统序列影像技术[T1加权成像和液体衰减反转恢复序列(FLAIR)]、新序列影像技术[如双反转序列(DIR)、液体和白质抑制序列(FLAWS)]、MRI形态学测量分析方法(MAP)以及正电子发射断层显像术(PET)观察和分析4例药物难治性眶额癫痫患者的神经影像学特征。根据SEEG结果和术前影像学评估结果制定手术方案,4例患者分别采用SEEG引导的眶额皮质射频热凝术和眶额皮质切除术。结果:4例患者的发作间期癫痫样放电位于额、颞区,其中3例放电侧别与手术部位侧别一致。4例患者的传统MRI序列影像均未发现病灶,T1加权成像数据经MAP分析后有3例患者发现眶额区异常。进行新序列扫描的3例患者中,2例患者在眶额区发现病灶,表现为灰白质交界模糊和皮质下白质信号升高。4例患者中,3例患者的PET在眶额区有局限性低代谢。4例患者的手术均顺利完成,术后无一例出现永久性神经功能障碍。术后随访时间分别为7、13、14、18个月,均无癫痫发作,其中3例随访时间>12个月患者的Engle分级均为Ⅰ级。结论:药物难治性眶额癫痫的传统MRI序列常表现为阴性;新序列影像(DIR和FLAWS)的阳性率高于传统MRI影像序列;MAP、发作间期PET可辅助定位病灶;多种影像学技术相互补充可提升药物难治性眶额癫痫的术前评估效率。

Objective To explore the application of new MRI sequence images in the diagnosis and treatment of drug-refractory orbitofrontal(OF)epilepsy.Methods We retrospectively included four consecutive patients with drug-refractory orbitofrontal epilepsy proven by SEEG between January 2016 and August 2018 at epilepsy center of Yuquan Hospital,Tsinghua University.Patients were analyzed in terms of their conventional sequence images(T1W and FLAIR),new sequence images(DIR,FLAWS),MRI image post-processing(MAP),and interictal PET image.Results Interictal epileptiform discharges were found over frontal and temporal deviations in all 4 patients on surface EEG;in three,the lateralization of interictal discharges was consistent with the surgical site side.The conventional MRI in this group were regarded as all negative.Three of the four patients had a MAP+abnormalities in the OF region after post-processing of T1 data.Among the 3 cases with DIR and FLAWS sequences,single lesion was found in the OF area in 2 cases,showing the blurred junction of the gray-white matter and the abnormal signal intensity of subcortical whiter matter in the OF area.Focal hypometabolic regions in the OF region were found in three of four patients.Three patients underwent SEEG-guided radiofrequency thermocoagulation in orbitofrontal cortex.After SEEG investigation,one patient underwent resective neurosurgery twice.The operations of all 4 patients were successful and no permanent neurological deficits occurred after operation.The postoperative follow-up time was 7,13,14,and 18 months,respectively,and there were no seizures.Among them,the Engle classification of 3 cases with follow-up time>12 months was all gradeⅠ.Conclusion The patients with OF epilepsy are often conventional MRI negative.New sequences(DIR and FLAWS)have a higher positive rate than traditional MRI sequences.MRI post-processing technology MAP and interictal PET can assist in the localization of lesions.The combination of multiple imaging techniques can improve the efficiency of preoperative assessment of OF epilepsy.