肉芽肿性多血管炎颅面受累的MRI表现

Magnetic Resonance Imaging Features of Granulomatosis with Polyangiitis in the Head

目的探讨肉芽肿性多血管炎(GPA)颅面受累MRI的特征,以提高对该病的认识。方法搜集2011年1月至2017年7月北京协和医院诊断为GPA/韦格纳肉芽肿(WG)的患者35例,对其颅脑MRI表现进行回顾性分析。结果GPA的主要特征:同时累及多个部位,包括副鼻窦、鼻、鼻咽及咽旁、乳突、眼眶、腮腺、脑膜、脑组织、垂体及脑神经。累及3个以上部位者占77%(27/35)。仅11%累及1个部位。颅内侵犯主要是硬脑膜,表现为弥漫性或局限性增厚并强化,多累及小脑幕、额颞部前中颅窝底部及海绵窦,2例合并脑神经强化;少数继发脑肿胀、梗死、出血和垂体受累。神经系统受累的病例均同时伴有颅面部结构的受累;颅面部病变:病变多弥漫分布,两侧受累程度多不对称;T_2WI病变信号较低,扩散加权成像(DWI)可见信号增高,表观扩散系数(ADC)减低;增强扫描病变多呈厚壁环形强化,边缘凹凸不平呈"花边样",病变形成肿块时中心不强化;鼻部受累表现,鼻甲/鼻中隔部分缺损、鼻腔空旷(8/35例);眼眶、鼻咽旁间隙(6/35例)"肿块样"改变,"钻缝样"弥漫填充周围脂肪间隙。结论GPA颅脑受累以多部位侵犯为主要特征,信号及强化形式有一定的特点,当颅脑MRI发现多部位病变,特别是同时存在鼻、鼻咽、副鼻窦、眼眶及硬脑膜病变时,鉴别诊断要考虑到GPA,对于临床已经诊断的GPA患者,颅脑MRI要重点观察以上部位。

Objective To describe the characteristics of MRI of craniocerebral involvement of granulomatous polyangi-itis(GPA)in order to improve the understanding of MRI manifestations of this disease.Methods Thirty-five patients di-agnosed with granulomatous polyangiitis/Wegener's granulomatosis from Peking Union Medical College Hospital from Janu-ary 2011 to July 2017 were retrospectively analyzed for MRI manifestations of their brains.Results The main features of GPA were as follows:(1)Multiple regions of involvement,including paranasal sinuses,nose,nasopharynx,parapharyn-geal,mastoid,orbital,parotid,meningeal,brain,pituitary,and cerebral nerves.77%(27/35)cases involved more than 3 regions.Only 11%cases involved 1 region.When GPA has intracranialinvolvement,the main region was the dura ma-ter,which manifested as diffuse or localized thickening and enhancement after Gd-DTPA administration,whereas 2 cases showed cerebral nerve enhancement.Other manifestations included brain swelling,infarction,hemorrhage,and hypophy-sis.Intracranial involvement was almost always accompanied by craniofacial structure involvement.Craniofacial lesions:Lesions were usually distributed in a diffuse and asymmetrical way.The lesions usually showed hypointensity in T2WI with increased DWI and decreasedADC.Lesions mostly showed thick lace-like ring enhancementafter Gd-DTPA administration.Nose involvement usually manifested as defect of on the nasal septum or emptiness of nasal cavity.Mass lesion was found in the orbit or paranasopharyngeal space with“drill stitch”.Conclusion The main MR feature of GPA is involvement of multiple regions. The signal,shape and enhamcement also have some characteristics. Those features are helpful in the dif- ferential diagnosis of GPA and in the the assessment of disease burden.