髓母细胞瘤的CT、MRI分析

目的:通过对髓母细胞瘤CT及MRI的影像分析,提高对本病的认识。方法:搜集经手术病理证实的髓母细胞瘤19例,全部病例均有CT和/或MRI资料。结果:19例中,肿瘤位于小脑蚓部15例,小脑半球4例。CT平扫肿瘤稍高密度9例,等密度2例,混杂密度3例,内伴斑片低密度灶及囊性变8例,有斑点状及斑片状钙化3例,CT增强扫描多强化明显。T1WI稍低信号10例,等信号及混杂信号2例,T2WI略高信号及混杂信号10例,等信号2例,肿瘤边缘较清楚,伴瘤周水肿9例。增强肿瘤均匀强化6例,不均匀强化4例。共15例见有第四脑室变形偏移及幕上脑室扩张。结论:常见髓母细胞瘤有特定的发生部位、好发年龄段及特征性CT和MRI表现,容易诊断;不典型髓母细胞瘤的表现在鉴别中要想到此病以减少误诊。

CT and MRI analysis of medulloblastomas

Objective:To promote the knowledge of medulloblastomas through analyzing CT and MRI features.Methods:19 cases with medulloblastomas proved by surgery and pathology had examined by CT or MRI scanning.Results:In this series of 19 cases with medulloblastomas,the lesion located in vermis in 15 cases and in cerebellar hemisphere in 4 cases.On CT plain scans,the tumors were slightly hyperdense in 9 cases,isodense in 2 cases and inhomogeneous density in 3 cases,the dotted hypodensity and cystic components in 8 cases and dotted calcification in 3 cases;many tumors were markedly enhanced on contrast CT image.MRI findings included:slightly hypointense in 10 cases and inhomogeneous isointense in 2 cases on T_1W1,inhomogeneous slightly hyperintense in 10 cases and isointense in 2 cases on T_2W1;tumors featured peritumoral edema in 9 cases.MRI showed homogeneous and inhomogeneous enhancement in 6 and 4 respectively,the fourth ventricle was deformed or deviated in 15 cases.Conclusion:The medulloblastomas have specific location,ages,characteristics and therefore are easy to diagnose.Identifying non-typical medulloblastomas are important to diminish misdiagnosis.