SPC DIR序列在一体化PET-MRI中对癫痫灶的定位诊断价值

The value of SPC DIR in localization diagnosis of epileptogenic foci on integrated PET-MRI

目的:探讨一体化PET-MRI检查中联合应用三维快速自旋回波双反转恢复(3D SPC DIR)序列和18 F-FDG代谢显像对脑内癫痫病灶的检出能力。方法:回顾性分析经手术病理证实的25例难治性癫痫的18 F-FDG PET-MRI资料。25例均为单发病灶,其中颞叶癫痫19例、额叶癫痫4例、顶叶癫痫2例。所有患者采用薄层T 1WI、T 2WI、磁化准备快速梯度回波序列(MPRAGE)和3D SPC DIR序列进行MRI检查。PET和MRI同步扫描。分析双反转恢复序列在PET-MRI检查中对致癫灶的定位诊断准确性。结果:25例患者中常规序列MRI联合18 F-FDG检出病灶13例(52%),SPC DIR序列联合18 F-FDG检出病灶21例(84%),两种检查方式对癫痫病灶定位诊断准确性的差异有统计学意义(χ2=4.50,P=0.034)。结论:癫痫灶术前定位采用一体化PET-MRI时,建议加扫3D SPC DIR序列,能提高病变检出率。

Objective:The purpose of this study was to explore the detection ability for epileptogenic foci using sampling perfection with applicitong-optimized contrasts by using different-flip angle evolutions(SPC DIR,also named as double inversion recovery)sequence combined with 18 F-FDG PET glucose metabolism imaging on integrated PET-MR.Methods:18 F-FDG PET-MRI images of 25 patients with surgery-pathologically proven intractable epilepsy were retrospectively analyzed.All patients underwent integrated PET-MRI examination.MRI sequences included conventional sequences,high definition thin layer magnetization prepared rapid acquired gradient echo(MPRAGE)sequences and SPC DIR sequence.PET and MRI scan were performed synchronously.The detection ability of epileptic foci of conventional sequences and double flip recovery sequence was analyzed.Results:According to the site of epileptic focus,totally 25 foci were found in 25 patients:19 in temporal lobe,4 in frontal lobe,and 2 in parietal lobe.Among these 25 lesions,52%(13/25)were displayed by conventional MR images,while 84%(21/25)were showed by SPC DIR sequence.The difference in diagnostic accuracy between conventional sequences combined with 18 F-FDG and SPC DIR sequence combined with 18 F-FDG was statistically significant.Conclusion:It is recommended that thin SPC DIR sequence should be added to the scan protocols when integrated PET-MRI is used for preoperative detection of epileptogenic lesions to increase positive rate.