血清AQP4-IgG阳性视神经脊髓炎谱系疾病MR影像学特征分析

MR imaging features of seropositive AQP4-IgG neuromyelitis optica spectrum disorders

目的分析血清水通道蛋白-4抗体(AQP4-IgG)阳性视神经脊髓炎谱系疾病(NMOSD)MR影像学特征,以提高对NMOSD的认识。方法收集10例经临床表现及血清学检查确诊为血清AQP4-IgG阳性NMOSD的病例资料,临床均以急性视神经炎、急性脊髓炎及最后区综合征三大核心症状的一种或多种就诊;每例患者均于治疗前行颅脑、全脊髓及眼眶MR平扫及增强扫描,回顾性分析血清AQP4-IgG阳性NMOSD的MRI影像学表现特征。结果10例血清AQP4-IgG阳性NMOSD患者,眼眶MR扫描5例表现出长节段视神经肿胀,T2WI信号增高,病变累及长度均大于视神经全长的1/2,其中4例累及双侧视神经,1例累及视交叉,增强扫描4例明显强化;脊髓MR扫描9例表现为长节段脊髓T2WI高信号病变,其中颈胸髓累及6例,胸髓累及2例,颈髓累及1例,病变累及长度均大于3个连续椎体节段,增强扫描4例轻度强化,5例无强化;颅脑MR扫描3例出现脑干病变,7例出现间脑、大脑半球病变,以大脑半球白质、侧脑室、第三及第四脑室室管膜周围、丘脑、扣带回或胼胝体分布为主,病变T1WI呈低或等信号,T2WI及T2WI-FLAIR呈高信号,增强扫描1例出现“云雾状”强化,1例出现室管膜线状强化,其他颅内病变无强化。结论血清AQP4-IgG阳性NMOSD的MR主要表现为双侧长节段视神经炎、长节段横贯性脊髓炎以及脑干、间脑及大脑半球病变。结合典型临床核心症状与MR影像学特征,需考虑到NMOSD的诊断。

Objective To analyze the imaging characteristics of seropositive aquaporin-4 immunoglobulin G (AQP4-IgG) neuromyelitis optica spectrum disorders (NMOSD).Methods Clinical records of 10 patients with seropositive AQP4-IgG NMOSD were reviewed.All patients presented with 1-3 of the clinical characteristics including acute optic neuritis,acute myelitis and area postrema syndrome.The nonenhanced and enhanced brain,spine and orbit MRI on all patients were analyzed retrospectively.Results Orbital MRI showed swelling and T2 hyperintensity involving over half of the optic nerve length (5/8) bilaterally (4) or optic chiasm (1),with obvious contrast enhancement (4).Spinal MRI showed longitudinal T2 hyperintense lesions (9/10) in both cervical and thoracic spinal cord (6),thoracic cord (2),and cervical cord (1) extending over 3 vertebral segments.The cord lesions did not enhance (5) or enhanced slightly (4) with contrast.Brain MRI showed T1 iso- or hypointense and T2 hyperintense lesions in the brainstem (3) or cerebral deep white matter (7) around the ependyma of the lateral,third and fourth ventricles,thalamus,cingulate gyrus and corpus callosum.There was no (8),cloud-like (1),or ependymal linear (1) enhancement.Conclusion MR features of seropositive AQP4-IgG NMOSD are mainly extensive optic neuritis,longitudinal extending transverse myelitis,brainstem,diencephalon and cerebral white matter lesions.