自身免疫性脑炎患者18F-FDG PET/CT影像学特征

Imaging features of 18F-FDG PET/CT in patients with autoimmune encephalitis

目的研究自身免疫性脑炎(AE)患者脑部18F-脱氧葡萄糖(FDG) PET/CT影像学特征,探讨PET/CT在AE早期诊断中的应用价值。方法收集2012年3月至2017年12月16例(男□例,女5例,年龄11-68岁)未经免疫治疗的脑脊液或(和)血清自身免疫抗体阳性的AE患者资料,分析患者18F-FDG PET/CT、MRI的影像及临床特征。结果16例AE患者中有9例抗N-甲基-D-天冬氨酸受体(N MDAR)抗体脑炎、7例边缘性脑炎(LE),LE组中抗γ-氨基丁酸B型受体(GABABR)抗体脑炎3例、抗富亮氨酸胶质瘤失活蛋白l(LGIl)抗体脑炎2例、抗Hu抗体脑炎1例、抗Yo抗体脑炎1例。15例显示脑内散在的18F-FDG代谢增高或减低灶,阳性率为15/16;其中抗NMDAR抗体脑炎表现为散在的额叶、额叶、顶叶等高代谢灶及枕叶低代谢灶,LE表现为额叶、海马等边缘系统的高代谢灶,同期CT密度均未见异常。MRI示部分患者T21T2液体衰减反转恢复序列(FLAIR)、弥散加权成像(DWI)呈稍高信号,阳性率为7/160结论不同类型的AE患者脑PET/CT影像特征不同。18F-FDG PET/CT对AE患者的早期诊断阳性率高。

Objective To study the imaging features of 18F-fluorodeoxyglucose(FDG) PET/CT in patients with autoimmune encephalitis (AE) and evaluate the value of PET/CT on early diagnosis of AE. Methods Sixteen patients with AE (11 males, 5 females, age: 11-68 years) between March 2012 and December 2017 were included. Patients had positive antibodies in cerebrospinal fluid or (and) serum without immunity therapy. The imaging (18F-FDG PET/CT, MRI) and clinical data were analyzed. Results Nine patients suffered from anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and other 7 patients had limbic encephalitis (LE), which including 2 cases of anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis, 3 cases of anti-γ-aminobutyric acid-B receptor(GABABR) encephalitis, 1 case of anti-Hu encephalitis and 1 case of anti-Yo encephalitis. Fifteen patients showed scattered hypermetabolism or hypometabolism in the brain on PET/CT imaging, and the positive rate was 15/16. Among those patients with anti-NMDAR encephalitis, hypermetabolism in frontotemporal parietal lobes and hypometabolism in occipital lobe were shown;hypermetabolism in limbic systems including temporal lobe and hippocampus were shown in LE.No abnormal CT density was found at the same phase. Slightly higher signals on , fluid-attenuated inversion recovery (FLAIR) and diffusion weighted imaging (DWI) were detected in some patients, and the positive rate was 7/16. Conclusions Patients with AE of different types have different characteristics on 18F-FDG PET/CT. 18F-FDG PET/CT has high positive rate for early diagnosis of AE.