【摘要】 目的探讨儿童后颅窝肿瘤的MRI特征与临床表现,以提高临床对该病的认识,降低误诊率。方法收集2014年2月至2015年8月于四川大学华西第二医院经术后组织病理学检查确诊为儿童后颅窝肿瘤的8例患儿的临床病历资料及MRI影像学资料为研究对象。MRI检查方法:对本组8例患儿均采用飞利浦1.5T MRI扫描仪,信号采集使用头部线圈,常规扫描包括轴位T1WI、T2WI、T2水抑制及矢状位T1WI。本组8例患儿中,对其中4例进行经肘静脉注射钆(Gd)对比剂MRI增强扫描。采用回顾性分析方法分析本组8例后颅窝肿瘤患儿的MRI特征与临床表现,评价MRI对儿童后颅窝肿瘤的诊断和治疗评估价值,并对本组被误诊的患儿进行临床误诊原因分析。本研究遵循的程序符合本院人体试验委员会所制定的伦理学标准,得到该委员会批准。结果按照后颅窝肿瘤组织病理学分型标准,将本组8例患儿分为髓母细胞瘤(2例)、小脑毛细胞星形细胞瘤(1例)、脑干胶质瘤(3例)、室管膜瘤(1例)及间变性室管膜瘤伴脑脊液转移(1例)。后颅窝肿瘤的临床表现不具有特异性,患儿常均以运动障碍、头痛、呕吐、咳嗽及精神症状等非特异性症状就诊。其MRI共同特征为:后颅窝内肿块影,累及脑干、第四脑室及小脑等后颅窝结构。不同病理类型的儿童后颅窝肿瘤的临床特征与MRI影像学表现:1髓母细胞瘤(2例)临床特征:运动障碍、面瘫等症状;MRI影像学表现:小脑蚓部实质性肿块,信号不均匀,可见囊变灶,肿块向下生长填充于第四脑室,伴有幕上梗阻性脑积水。2小脑毛细胞星形细胞瘤(1例)临床特征:以运动障碍、步态异常等症状为主;MRI影像学表现:小脑半球结节,具有明显前移,可见囊变灶,呈大囊小结节表现。3脑干胶质瘤(3例)临床特征:以步态不稳、饮水呛咳、说话不清等症状为主;MRI影像学表现:桥脑或延髓肿块影,强化不明显,局部呈花边样或环形强化。4室管膜瘤(2例)临床特征不具有特异性;MRI影像学表现:第四脑室内肿块影,可见囊变灶,肿块经第四脑室侧孔及中间孔向脑室外生长的挤牙膏样特征,恶性室管膜瘤伴有脑脊液播散转移。本组被临床误诊的3例患儿中,1例为脑干胶质瘤,初诊时因其反复咳喘症状被误诊为迁延性肺炎。1例为脑干多型性胶质母细胞瘤。初诊时因其运动障碍、头晕而被误诊为免疫性脑炎。1例为后颅窝间变性室管膜瘤,因脑脊液播散至胸、腰段髓外转移,而被临床误诊为格林巴利综合征。3例本患儿被误诊的主要原因为:后颅窝肿瘤的临床症状不具有特异性,未及时进行脑部MRI检查之故。结论不同病理类型的儿童后颅窝肿瘤在MRI影像学表现上具有一定特征性表现。对该病患儿早期进行MRI检查,可降低对儿童后颅窝肿瘤的误诊与漏诊发生。MRI影像学检查在儿童后颅窝肿瘤的诊断与鉴别诊断中有较大临床意义。更多还原

【Abstract】 Objective To study MRI and clinical manifestation of posterior cranial fossa tumors in children,in order to improve the recognition of clinical and decrease the misdiagnosis rates on posterior cranial fossa tumors in children.Methods From February 2014 to April 2015,a total of8 cases of children with posterior cranial fossa tumors in West China Second University Hospital,Sichuan University who diagnosed by postoperative pathological examination were enrolled in the study.MRI examination method to posterior cranial fossa tumors in children:craniocerebral scanning was performed by 1.5T MRI in all 8cases of patients.MRI conventional scanning included T1 WI,T2WI,T2W-flair and sagittal T1 WI.Gadolinium(Gd)contrast enhanced T1 WI was performed in4 cases.MRI and clinical characteristics were retrospectively analyzed.The value of MRI in diagnosis and treatment of children with posterior cranial fossa tumors were evaluated.The causes of clinical misdiagnosis of were analyzed.The study protocol was approved by the Ethical Review Board of Investigation in Human Being of West China Second University Hospital,Sichuan University.Results According to the criteria of pathological classifications of posterior cranial fossa tumors,8cases of posterior cranial fossa tumors were divided into medulloblastoma(2cases),cerebellar hair cell astrocytoma(1case),brain stem encephalitis(3cases),ependymoma(1case)and anaplastic ependymoma(1case).The clinical manifestations of the 8patients were non-specific,which were dyskinesia,headache,vomiting,cough and etc..The common MRI features were tumors in the posterio cranial fossa which involved in brain stem,fourth ventricle and cerebellum.The specific clinical manifestations and MRI features of different pathological classifications of posterior cranial fossa tumors were as follows.1Medulloblastoma(2cases)was with dyskinesia,facial paralysis,and solid masses in the vermis cerebelli.2Cerebellar hair cell astrocytoma(1case)was with dyskinesia,gait abnormal,and obvious enhancement nodule in the cerebellar.3Brain stem encephalitis(3case)was with instability of gait,dysdipsia,dysphonia,and masses in the brain stem enhanced lightly.4Ependymoma(2case)was without specific clinical features and with tumor in the forth ventricle grew through the lateral aperture and with metastasis by cerebrospinal fluid.Among 8cases,3cases were clinically misdiagnosed,2 cases were brain stem encephalitis and 1 case was anaplastic ependymomas.The reasons of clinical misdiagnosis were the nonspecific signs and symptoms,and the delayed cranial MRI examination.Conclusions There were some significant MRI features in posterior fossa tumors in children.Early application of MRI and acquaintance with the clinical manifestations can reduce the clinical misdiagnosis rate.MRI is of great significance in diagnosis and differential diagnosis of posterior cranial fossa tumors in children.更多还原