腮腺单发肿块的MRI诊断

MRI Diagnosis of Solitary Parotid Masses

目的 MRI在腮腺肿块的诊断中具有明显优越性,本研究分析腮腺单发肿块的MRI表现及特征。资料与方法回顾性分析128例经手术病理证实的腮腺单发肿块的MRI表现,其中35例行增强扫描,观察肿块部位、形态、边缘、大小、信号、增强表现及伴随征象。结果 107例良性肿块中,除2例炎性肿块外均边界清晰,以腺瘤(57例)及腺淋巴瘤(31例)最常见,两者发生部位及T2WI信号差异有统计学意义(P<0.01)。腺瘤T2WI以高信号为主(55例,96.5%),40例(70.2%)见囊变;而腺淋巴瘤均发生于中老年男性且位于腮腺后下极,12例T2WI呈等/低信号,19例呈稍高信号,3例呈囊实性。21例恶性肿瘤中,15例(71.4%)形状不规则,18例(85.7%)边界模糊,15例(71.4%)T2WI呈等或低信号为主混杂信号;增强扫描6例显著强化,6例不规则环形强化,伴周围结构侵犯4例(19.0%),颈部淋巴结肿大7例(33.3%);恶性病灶在形态、边界、T2WI信号及伴随征象上与良性病灶差异有统计学意义(P<0.01)。结论腮腺单发肿块的MRI征象对病灶良恶性的鉴别及腺瘤和腺淋巴瘤的鉴别具有一定的价值。

Purpose MRI has obvious superiority in the diagnosis of parotid tumor, this study aims to analyze the MRI manifestations and features of solitary tumors of parotid gland. Materials and Methods MRI findings of 128 patients with pathologically proved parotid isolated mass were retrospectively reviewed, among them 35 underwent contrast-enhanced imaging, the location, shape, margin, size, signal, enhancement and accompanying signs of the lesions were observed. Results 107 parotid benign mass showed clear and smooth boundary except inflammatory mass, adenomas（n=57） and adenolymphoma（n=31） were most common seen, there were statistically significant differences between them on location and T2 WI signal（P〈0.01）. Adenomas showed high signal mainly on T2WI（n=55, 96.5%）, and cystic degeneration in 40 cases（70.2%）; while adenolymphomas all had their onset in aging male, and located in the posterioinferior portion, manifested as iso- or low signal on T2 WI in 12 cases, slightly high signal in 6 cases, and cystic solid in 3 cases. Among the 21 malignant tumors, 15 cases（71.4%） showed irregular shapes, 18 cases（85.7%） showed unclear borders, and 15 cases（71.4%） showed mixed signal mainly with iso- or low signal on T2WI; in contrast-enhanced scan, 6 cases were significantly enhanced, 6 cases showed irregular ring-like enhancement, with surrounding invasion in 4 cases（19.0%）, neck lymph nodes enlargement in 7 cases（33.3%）; there were statistically significant differences（P〈0.01） between malignant and benign tumors on shape, border, T2 WI signal and accompanying signs（P〈0.01）. Conclusion Parotid single mass carry certain MRI characteristics which are helpful in differentiating the benign tumors from the malignant ones and adenomas from adenolymphoma.