儿童危重症甲型H1N1流感中枢神经系统并发症的影像学表现

目的：探讨儿童危重症甲型H1N1流感中枢神经系统（CNS）并发症的影像学特点。方法：回顾性分析8例危重症甲型H1N1流感伴CNS并发症的临床及影像学资料,所有患儿住院期间均行MRI平扫及增强扫描,其中3例行CT扫描。结果：4例为流感相关脑病,影像学检查未见明显异常,痊愈出院。死亡4例,其中3例并发急性坏死性脑炎（ANE）,影像表现为多灶性、对称性脑部损害,以双侧丘脑受累为特征,内囊、豆状核、脑干及大小脑髓质均可受累,病变区CT呈低密度,MRI呈长T1、长T2信号,DWI示双丘脑中心区呈低信号,周边呈高信号;ADC图示中央呈稍高信号,环状略低信号环绕。另1死亡病例并发颅内真菌感染,真菌性脑膜炎MRI见脑膜明显强化,真菌性肉芽肿MRI呈类圆形稍长T1、长T2信号,增强边缘强化。结论：儿童危重症甲型H1N1流感CNS并发症有：流感相关脑病、ANE和机会性真菌感染。ANE病死率高,但其影像表现有相对特征性。

Imaging features of associated neurologic complications in pediatric patients with critical influenza A (H1N1 )infection

Objective：To study the imaging features of associated central nervous system complications in pediatric patients with critical influenza A （H1N1 ）infection.Methods：The clinical and imaging materials of 8 cases with critical influenza A （H1N1） infection associated neurologic complications were analyzed retrospectively.All of the patients underwent plain and enhanced MR scanning,3 of them also had CT scan.Results：Of these 8 pediatric patients,4 patients were complicated with influenza related encephalopathy,no neuro-imaging abnormalities was assessed and the patients were cured and discharged.Four patients died;3 of them were complicated with acute necrotizing encephalopathy （ANE）,and the other one had complicated intracranial fungal infection.Image features of ANE were multiple,symmetric brain lesions,the characteristic position involved were bilateral thalami,the internal capsule,lenticular nucleus,brainstem and medulla of cerebrum and cerebellum could also be involved.The above-mentioned regions involved were hypo-attenuated on CT,and with prolonged T1 and T2 signal intensities on MRI,the center of bilateral thalami showed low signal intensities with high signal intensities in the periphery on DWI.Relative high signal intensities in the center and surrounded by slightly low signal intensities were displayed on ADC map.Image findings of intracranial fungal infection were fungal meningitis with significant meningeal enhancement on MRI,fungal granuloma showed prolonged T1 and T2 signal intensities with rim enhancement.Conclusion：Influenza-related encephalopathy,ANE and opportunistic fungal infection are the main neurologic complications of critical influenza A （H1N1） in children.The prognosis of ANE is poor with high mortality,its imaging findings are relatively characteristic.