髓母细胞瘤的MRI征象分析与病理对照

摘要

Objective:To explore MRI manifestation of medulloblastomas (MB). Methods:26 cases with MB proved by pathol-ogy were reviewed,including MR imaging and clinical data. All patients were examined with conventional MRI,enhanced MRI and DWI. Results:26 cases with MB were single lesion. 15 lesions (58%) were located in the fourth ventricle,7 cases (27%) in cerebellar vermis,4 cases (15%) in cerebellar hemisphere. Most tumors demonstrated hypo- or iso-intense on T1WI and mild to significant hyper-intense on T2WI,DWI of the solid component showed slightly high,high and obviously high signal,ADC maps were all low signal. Cyst degeneration or necrosis was seen in the 12 lesions,while one lesion had bleeding with the tu-mor. 5 cases spread into subarachnoid space. Conclusions:Conventional MRI combined with DWI and ADC has important value in diagnosis and differential diagnosis of medulloblastoma,and has important diagnostic value of metastatic carcinoma.%目的：探讨后颅窝髓母细胞瘤（medulloblastoma，MB）的MRI表现，以提高诊断准确率。方法：回顾性分析经手术病理证实的26例MB的MRI及临床资料，并将MRI表现与病理进行对照研究，患者均行MRI平扫、增强扫描及DWI检查。结果：26例均为单发病灶，其中15例位于第四脑室内（占58%），7例位于小脑蚓部（占27%），4例位于小脑半球（占15%）。肿瘤在T1WI上呈等至低信号，T2WI呈稍高或高信号，DWI上肿瘤实性成分呈稍高、高及明显高信号，ADC图均为低信号。12例病灶内可见囊变、坏死，囊变坏死区与脑脊液信号相近，1例合并出血。增强扫描肿瘤实质成分强化特征不一，呈轻度至明显强化。5例沿脑脊液播散。结论：常规MRI结合DWI及ADC图对MB的诊断、鉴别诊断，以及沿脑脊液种植转移的诊断具有重要价值。