目的 探讨幕上非典型畸胎样/横纹肌样瘤(atypical teratiod/rhabdoid tumor,AT/RT)影像学表现及鉴别诊断,提高对该肿瘤的认识.方法 结合文献回顾性分析2例幕上AT/RT影像学征象.结果 肿瘤较大,多呈分叶状,境界清晰或不清,占位效应明显,周围脑水肿较重,CT上呈混杂密度改变,增强后呈中等-明显强化;MR T1加权肿瘤呈等低混杂信号,T2WI表现为高、等、低混杂信号,增强后肿瘤实性成分呈中等-显著强化,囊性区域边缘可见带状强化或部分带状强化,累及脑膜可出现长"脑膜尾"征.结论 幕上AT/RT无特征性影像学表现,在鉴别诊断上具有重要价值,最后确诊需病理学及分子遗传学特征.%Objective To study imaging findings and differentiating diagnosis of atypical teratoid/rhabdoid tumor. Methods The imaging manifestations of 2 cases with the supratentorial atypical teratoid/rhabdoid tumor were analyzed retrospectively,with literature review. Results The tumors were larger in size and lobulated with clear or unsharp borders and obviously space occupying effect,there was severe encephaledema nearby. On CT,the tumors apeared as mixed density and moderate to obvious enhancement after contrast medium injection,while on MR imaging,the tumors were iso- or low dense on T1WI and mixed hyper-,iso-,hypo-dense on T2WI,and moderately-conspicuously enhanced in parenchyma, completely or partly enhanced like braid around the cystic area after contrast-enhanced examination. The dural tail sign might appeared if the meninges implicated. Conclusion There are no characteristic imaging manifestations for the supratentorial atypical teratoid/rhabdoid tumor,the diagnosis should depend on pathology and molecular genetics.
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