成人髓母细胞瘤的多模态MRI表现及误诊分析

目的探讨成人髓母细胞瘤多模态MRI表现,加深对该肿瘤的认识及提高术前诊断水平。材料与方法搜集经手术病理证实的16例成人髓母细胞瘤患者的临床资料及MR图像进行回顾性分析。结果1例位于桥小脑角区,1例位于右枕顶叶伴出血,7例位于小脑半球,6例位于蚓部-四脑室,1例多发;8例有小血管穿行。肿瘤均有囊变,实性成分T1WI呈等或稍低信号,T2WI及液体衰减反转恢复序列(fluid attenuated inversionrecovery,FLAIR)序列呈等或稍高信号;扩散加权成像(diffusionweighted imaging,DWI)为高信号,平均ADC值为0.589×10-3mm2/s;5例中度强化,4例明显强化,5例斑片状或片絮样轻度强化。7例有磁共振波谱(MR spectroscopy,MRS),Cho峰明显升高,NAA峰明显降低,Cho/NAA值(≥4.8)明显增高;3例行扩散张量成像(diffusion tensor imaging,DTI)检查,瘤周白质纤维束推移、部分断裂。结论成人髓母细胞瘤多模态MRI表现有一定的特征,有助于术前对该肿瘤做出准确诊断。

Multimodal MRI findings and misdiagnosis analysis of adult medulloblastoma

Objective:To discuss multimodal MRI findings of adult medulloblastoma,the understanding of the tumor is deeped and the level of preoperative diagnosis is improved.Materials and Methods:Retrospective analysis of clinical datas and multimodal MRI images of 16 adults medulloblastomas confirmed by pathology.Results:One case was multiple,1 case was located in the cerebellopontine angle area,1 case was located in the right frontal and parietal lobes,7 cases were located in the cerebellar hemisphere,and 6 cases were located in the vermis-four ventricle.One case had bleeding,8 cases had small blood vessel permeation signs.Tumors have cystic changes.Solid components of tumors showed equal or slightly lower signals on T1WI,T2WI and FLAIR sequences showed equal or slightly higher signals.diffusion weighted imaging(DWI)showed high signal and average ADC value was 0.589×10-3 mm2/s.Five cases were moderately enhanced,4 cases were significantly enhanced,1 case showed obvious ring enhancement and 5 cases were patchy or flake-like mildly enhanced.In 7 cases with MR spectroscopy(MRS),the Cho peak was significantly increased,the NAA peak was significantly decreased,and the Cho/NAA value(≥4.8)was significantly increased.Three cases had the diffusion tensor imaging(DTI)examinations.The peritumoral white matter fibers were pushed and some fibers were broken.Conclusions:Multimodal MRI findings in adult medulloblastoma have certain characteristics and are helpful for accurate diagnosis before surgery.