鞍区青少年毛细胞星形细胞瘤的MRI诊断

目的　分析发生在鞍区的青少年毛细胞星形细胞瘤的MRI特点及临床发病特点。方法　经手术病理证实的鞍区青少年毛细胞星形细胞瘤 2 4例 ,回顾性分析其MRI表现。结果　青少年毛细胞星形细胞瘤在MRI表现上有如下特点 :(1)肿瘤在T1WI上表现为稍长T1、等T1、稍长T1与等混杂T1或长T1信号 ,在T2 WI上大多表现为长T2 信号 ,注射对比剂后 ,肿瘤实性部分可见显著强化 ;(2 )不规则分叶状 ,边界光滑锐利 ,几乎没有瘤周水肿 ;(3)瘤内多发微囊变 ,出血少见 ;(4)鞍上非偏心性生长 ,常长入垂体窝 ,突入第 3脑室底部引起幕上脑积水 ;(5 )沿视觉通路生长。此外 ,这些病人就诊时多有单侧性视力下降或失明 ,而大多没有下丘脑及垂体内分泌异常症状 ,仅 2例有多饮多尿表现。结论　鞍区青少年毛细胞星形细胞瘤有比较典型的MRI特点 ,结合患者的年龄、性别及临床发病特点 ,有助于其术前诊断

Thejuvenile pilocytic astrocytoma of sellar region: MRI manifestations

Objective To study the MRI findings and the clinical features of the juvenile pilocytic astrocytoma of sellar region Methods The MRI findings of 24 patients with the juvenile pilocytic astrocytoma of sellar region were reviewed retrospectively All cases were proved by operation and pathology Results The MRI characteristics of juvenile pilocytic astrocytoma in sellar region were as follows: (1)The tumors appeared slight hypo , hypo or isointense on T 1 weighted images and hyperintense on T 2 weighted images; after contrast injection, the lesions usually enhanced markedly (2)Tumors were all sharply demarcated and rarely had associated edema The lesions tended to be irregular multilobulated in shape (3) Mutiple microcysts in tumors were often observed but hemorrhage rarely seen (4) Tumors extended into the pituitary fossa with midline growth; and invaded the floor of the third ventricle and caused hydrocephalus (5) Tumors usually grew along the visual pathway Furthermore, patients suffered from monocular visual disturbances and lacked of hypothalamic and pituitary dysfunction Conclusion The MRI appearances of the juvenile pilocytic astrocytoma in sellar region were characteristic It is easily differentiated from other lesions of sellar region by using correlated clinical features