腮腺脂肪瘤的CT与MRI影像学表现

CT and MRI imaging characteristics of lipoma of parotid gland

目的:探讨腮腺脂肪瘤的CT与MRI表现特点,并与病理结果对照,以提高对该病的认识。方法:回顾性分析经手术病理证实的16例腮腺脂肪瘤患者的CT与MRI资料(CT检查12例,MRI检查10例,其中有6例分别行CT、MRI检查)。对肿瘤的部位、大小、形态、边界、内部密度(信号)、增强特点及病灶周围有无肿大淋巴结等进行分析,并与病理结果相对照。结果:所有病例均为单侧发病。浅叶10例,深叶5例,浅、深叶均受累为1例。病灶最大直径为1.3~11.8 cm,平均(4.23±3.06)cm。病灶呈边缘光整的圆形或椭圆形为11例,呈边缘分叶状、不规则肿块为5例。密度(信号)均匀11例,不均匀5例。12例CT平扫示,病灶呈脂肪样低密度9例,混杂密度3例,其中2例伴钙化团块;10例MRI病灶表现为T1WI高信号,T2WI中等或稍高信号,6例信号强度均匀,4例内部伴有团状或条索样低信号,脂肪抑制序列呈均匀或不均匀低信号。增强CT和增强MRI示,病灶无明显强化5例,轻度不均匀强化5例。病灶周边均未见明显肿大淋巴结。结论:腮腺脂肪瘤具有特征性的影像学表现,且与肿瘤的病理特点相关,CT与MRI有利于准确诊断及术前评估病变范围。

Objective:To investigate the CT and MRI manifestations of lipoma of the parotid gland,and compare with the pathological results for improving recognition of this disease.Methods:The CT and MRI data of 16 patients with lipoma of parotid gland confirmed by pathology were analyzed retrospectively,CT scanning was performed in 12 cases and MRI in 10 cases,including 6 cases performed both CT and MRI.The imaging findings including location,size,morphology,margin,density(signal),enhancement pattern as well as lymphadenopathy were evaluated,and compared with the pathological results.Results:All 16 lipomas were located unilaterally.10 cases were located in the superficial lobe,5 cases were located in the deep lobe,1 case extending from superficial to deep lobe.The maximum diameter of the tumors ranged from 1.3 cm to 11.8 cm,the mean maximum diameter was(4.23±3.06)cm.11 cases showed round or oval shape with circumscribed margin,5 cases showed lobulated or irregular shape.Homogeneous CT density or MRI signal intensity was seen in 11 cases,while heterogeneous CT density or MRI signal intensity was seen in 5 cases.Of the 12 cases underwent plain CT scan,9 cases showed low fat density,3 cases showed mixed density,including 2 with calcification;10 cases of MRI showed high-intensity on T1WI,and medium or slightly high intensity on T2WI,6 cases showed homogeneous intensity,4 cases showed patchy or cord-like hypo-intensity,which showed homogeneous or heterogeneous weak signal on fat-suppressed images.After contrast enhancement,5 cases showed no contrast enhancement,5 cases showed slightly heteroge neous enhancement.There is no obvious lymphadenopathy around these lesions.Conclusion:The lipoma of parotid gland had characteristic imaging features,which correlated to the pathological changes.CT and MRI may contribute to a preoperative diagnosis of this tumor,as well as the accurate assessment of lesion extent.