儿童后颅窝常见肿瘤的MRI影像学特征分析

MRI imaging features of common tumors in posterior cranial fossa of children

目的探讨儿童后颅窝肿瘤的磁共振(MRI)影像学特征。方法回顾性分析20例经手术病理证实的儿童后颅窝肿瘤的MRI和临床资料。结果 6例星形细胞瘤MRI平扫以T1WI等低信号,T2WI混杂信号为主,其中4例部分囊性变,增强后明显不均匀强化,1例完全囊性变。10例髓母细胞瘤以T1WI稍低信号、T2WI等或稍高信号为主,其中5例病灶信号欠均匀,伴有多个小囊边区。4例室管膜瘤,均位于四脑室区,以T1WI等、低信号,T2WI高或稍高信号为主,呈明显不均匀强化,伴梗阻性脑积水。结论儿童后颅窝肿瘤的MRI表现具有一定的特征性,MRI对儿童后颅窝肿瘤的定位和定性诊断具有重要的临床价值。

Objective To investigate the MRI imaging features of common tumors in posterior cranial fossa of children. Meth- ods MRI imaging data of 20 children with tumors in posterior cranial fossa that had been clinico-pathologically demonstrated were ret- rospectively analyzed. Results Six cases with astrocytoma mainly showed iso- and hypo-density on T1WI and mixed signal intensity on T2WI sequences. Of the astrocytoma cases,four had cystic changes,and one case presented completely cystic. Ten cases with medullo- blastoma showed slightly hypo-dense signal intensity and iso- or slightly hyper-intense signal intensity on T1WI and T2WI sequences, respectively. Very little cystic changes were found in the type of tumors. Four cases with ependymoma were located at the fourth ventri- cle,and mainly showed iso- and hypo-signal intensity on T1WI and high or slightly higher signal intensity on T2WI. All the medullo- blastomas were heterogeneously enhanced with obstructive hydrocephalus. Conclusions There are certain MRI imaging features of tumors in posterior cranial fossa of children. MR1 has clinically significant in the locating and characterizing tumors in posterior cranial fossa of children.