目的探讨中枢性原始神经外胚层肿瘤(primitive neuroectodermal tumor,PNET)的影像表现特征,以提高对此病的认识。方法回顾性分析经手术病理证实的9例PNET患者的CT和MRI资料。结果发生于大脑半球7例,脑干及松果体区各1例。9例病灶边界均清晰,密度或信号不均匀。CT平扫实质部分与脑灰质等或稍高密度,MRI上T1WI呈与脑灰质等或稍低信号,T2WI呈等或稍高信号。7例无或轻度瘤周水肿;6例有明显占位效应;瘤内出血6例,钙化5例;6例见流空血管信号穿行,6例与侧脑室关系密切。5例与局部硬脑膜相连,其中2例邻近骨质变薄,增强扫描多明显强化。结论 PNET影像学表现有一定特征性。 Objective To explore the imaging features of central primitive neuroectodermal tumor (PNET) in order to improve the understanding of the disease. Methods The CT and MRI data of 9 PNET patients confirmed by surgery and pathology were retrospectively analyzed. Results occurred in the cerebral hemisphere in 7 cases, 1 in the brainstem and pineal region. The border of 9 cases were clear, the density or signal was not uniform. CT scan of the essence and gray matter or slightly higher density, T1WI MRI with gray matter or slightly lower signal and T2WI was equal or slightly higher signal. 7 cases had no or mild peritumoral edema; 6 cases had significant mass effect; 6 cases had intratumoral hemorrhage and 5 cases calcified; 6 cases had traumatic vascular signal passing through and 6 cases had close relationship with lateral ventricle. 5 cases were connected with the local dura, including 2 cases of adjacent bone thinning, enhanced scan and more significantly enhanced. Conclusion PNET imaging has some characteristics.