儿童颅内毛细胞星形细胞瘤的MRI表现

摘要

Objective To investigate the MRI feature of intracranial pilocystic astrocytoma( PA) in children. Methods MRI features of 38 cases with PA proved by operation and pathology were retrospectively analyzed. Results 21 PA located at infratcntorial, 13 cases located at supratcntorial, 1 case located at infratcntorial and supratcntorial. MRI features could be divided into 4 types:① Solid typc(n=18) , 9 cases located at scllar region, 2 cases located at cerebral hemisphere, 5 cases located at brain stem, 1 case located at ccrcbcllar hemisphere, 1 case located at both infratcntorial and supratcntorial. ②Solid-cyst typc(n=14), 10 cases located at ccrcbcllar hemisphere, 2 cases located at brainstem, 1 case located at pineal region, and 1 case located at cerebral hemisphere. ③ Cyst-node typc(n =5) , all the 5 cases located at ccrcbcllar hemisphere. ④Cyst typc(n= 1 ) , located at pineal region. The cystic part of the tumors appeared hypointense on T1 flair, hypcrintense on T2WI. The solid part and cyst wall solid part appeared hypointense or isointense on T, flair, hypcrintense on T2 flair and hypointense or isointense on DWI. After injection of contrast medium, the solid part, wall node and cyst wall of tumors showed obvious enhancement. The cystic part of tumor did not show enhancement. Dissemination, hemorrhage, and calcification were in each one case. There were 11 cases showed mild edema around the tumors, which were located at ccrcbcllar and cerebral hemisphere, no edema at scllar region. Conclusion The pediatric PA in MRI appearances has characteristic features. Most PA occurred in cerebellum and cerebral hemispheres were solid-cyst mass. The lesions occurred in scllar region were solid mass. The tumors always with mild edema, and showed cyst-solid type when located in cerebellum and cerebral hemispheres. The tumor located at scllar often showed no edema.%目的 探讨儿童颅内毛细胞星形细胞瘤(PA)的磁共振成像(MRI)表现.方法 回顾性分析经手术病理证实的38例毛细胞星形细胞瘤的影像学表现,MRI表现分为实性型、囊实型、壁结节型、单纯囊肿型.结果 24例(63.15%)病灶位于幕下,13例(34.21%)位于幕上,1例(2.6%)累及幕上和幕下,实性型18例,鞍区9例,大脑半球2例,小脑半球1例,脑干5例,1例幕上及幕下多发;囊实性型14例,小脑半球10例,脑干2例,松果体区1例,大脑半球1例;囊壁结节型5例,均位于小脑半球;单纯囊肿型1例,位于松果体区.各型的囊性部分表现为T1低T2高信号,实性部分及壁结节为T1等或低T2高信号,DWI为低或等信号,增强后实性部分、壁结节及囊壁明显强化.出现播散、出血、钙化各1例.瘤周水肿,11例出现轻度水肿,10例囊实性型,1例壁结节型,均位于大脑半球和小脑半球,鞍区肿瘤无水肿.结论 儿童颅内毛细胞星形细胞瘤有一定的特征性,多位于小脑半球,以囊实型和壁结节型多见;鞍区以实性型多见;瘤周水肿常为轻度,多见于小脑半球和大脑半球,且在囊实性型中多见;鞍区无水肿.