腮腺多形性腺瘤的MR诊断

Pleomorphic adenoma of parotid gland: MR imaging findings

目的:探讨腮腺多形性腺瘤(pleomorphic adenoma,PA)的MRI特征,以提高术前诊断的准确性。方法:回顾性分析2005—2011年间17例经手术后病理检查证实的腮腺多形性腺瘤的MRI平扫加增强表现,其中男6例,女11例;年龄27～70岁,平均50岁。结果:17例患者的17个病灶均为边界清晰肿块,12例有分叶,16例可见包膜。病灶的最大径为1.0～6.3cm,平均2.6cm。与正常肌组织信号相比,肿瘤在T1WI呈等或略低信号,T2WI压脂相呈明显高信号。6例见囊变,2例有钙化影。增强后扫描,17个病灶均有明显延迟强化,其中,4例为均匀强化,13例呈不均匀强化。结论:腮腺单发孤立性病灶,MRI表现为边界清楚、有分叶、可见囊变(或)钙化、有包膜、增强扫描有明显延迟强化特点的肿块,应多考虑PA的可能。

PURPOSE：To evaluate the diagnostic value of MR imaging and conventional contrast-enhanced MR imaging appearance in pleomorphic adenoma（PA） of the parotid gland.METHODS： We retrospectively reviewed pre-and post-contrast MR images of pleomorphic adenoma with pathologic correlation in 17 cases（6 men and 11 women;median age,50 years;range,27-70 years） collected between 2005 and 2011 from our pathologic and radiologic database.RESULTS： All of the tumors showed well-defined margins,and 12 patients with lobulations.The tumors in 16 patients had capsules.The average maximal diameter was 2.6cm（ranged from 1.0 to 6.3cm）.Cystic changes were seen in 6 cases and calcification in 2 cases.On T1-weighted images（T1WI）,all tumors showed homogeneously SI equal or lower to normal muscle.On fat-suppressed T2-weighted images（T2WI）,all of them showed marked higher SI.On gadolinium-enhanced T1WI,all tumors demonstrated marked enhancement.The tumor showed homogenous enhancement in 4 cases and inhomogeneous in the remaining 13 cases.The enhancement pattern showed low wash-in.CONCLUSIONS： PA of the parotid gland tends to be an isolated and well-defined mass with lobulations,capsules and cystic and/or calcification changes on MR imaging.PA of the parotid gland had characteristics in delayed enhancement patterns.