头颈部副神经节瘤的影像学诊断

Imageologic Diagnosis of Head and Neck Paraganglioma

目的结合头颈部副神经节瘤的发生部位,分析其影像学表现和特点。材料和方法回顾性分析23例头颈部副神经节瘤患者的影像学资料(5例鼓室球瘤,12例颈静脉球瘤,3例迷走体瘤和3例颈动脉体瘤),21例行CT检查(其中1例行动态增强检查),15例行MRI检查。结果鼓室球瘤较小,多发生于鼓岬区;颈静脉球瘤以颈静脉孔为中心,较大的肿瘤侵犯咽旁间隙、中耳、外耳道、乳突和(或)颅内;颈动脉体瘤位于上颈部颈内外动脉分叉处,伴上述动脉明显分离移位;迷走体瘤位于咽旁颈动脉鞘区,血管移位不一。以上四类肿瘤CT平扫呈中等密度,强化显著,部分肿瘤内见强化的血管和囊性改变;MRIT1WI中低信号,强化显著,T2WI中高信号,部分肿瘤内见囊变,多数肿瘤中可见血管流空“盐和胡椒征”(鼓室球瘤和较小的颈静脉球瘤中不见)。鼓室球瘤和颈静脉球瘤边缘不规则,后者侵犯咽旁间隙部分边缘光滑,骨质呈虫咬状破坏;颈动脉体瘤和迷走体瘤边缘光滑,无骨质破坏。结论多数头颈部副神经节瘤具有特定的发生部位和特征性的CT和MRI表现,可据此确诊;发生于不同部位的肿瘤的影像学表现有所差别。

Purpose:To analyze the imaging features of the head and neck paraganglioma in combination with its origination.Materials and Methods:The images of23cases of head and neck paraganglioma(5gloˉmus tympanicum tumor,12glomus jugulare tumor,3vagal paraganglioma and3carotid body tumor)were retrospectively reviewed.Among them21were undertaken CT scan(1with dynamic enhanced CT)and15with MRI examination.Results:Most glomus tympanicum tumors were small and located in the area of cochlear promontory,whereas the glomus jugulare tumors were larger and situated in the jugular foramen as the centrality with some of them invading the parapharyngeal space,middle ear,external auditory canal,mastoid and/or intracranium.The carotid body tumors occurred in the bifurcation of the carotid artery with the splaying of the external and internal carotid artery.The vagal paragangliomas originated in the carotid space of the parapharynx with displacement of the vessels.These four kinds of paraganglioma had manifestations of moderate density on plain CT scan and marked enhancement on contrast images with enhanced vessels and cystic changes in some cases.On MRI images,the tumors had manifestations of low to moderate signal intensity on T 1 WI with intense enhancement and moderate to high signal intensity on T 2 WI.Cystic changes were also found in some tumors.The characteristic sign of flow voids representing intra-tumor vessels(also known as“salt-and-pepper appearance”)were seen in most cases(but not seen in glomus tympanicum tumors and small glomus jugulare tumors).The marˉgins of the glomus tympanicum tumors and glomus jugulare tumors were irregular with mouth-eaten patten of bone destruction.But the latter were smooth when the tumor invaded the parapharyngeal space.The carotid body tumors and vagal paragangliomas had smooth margins with no bony eroˉsion.Conclusion:Most head and neck paragangliomas have characteristic originations and imaging feaˉtures,therefore they can be accurately diagnosed.However,the tumors occurred in different positions have some different features.