胸腺肿瘤的MRI分类诊断探讨

A preliminary investigation of MRI categorization of thymic tumors

目的探讨借鉴乳腺影像报告和数据系统(breast imaging reporting and data system,BI-RADS)分类方式对胸腺肿瘤MRI表现进行分类诊断的可行性。材料与方法纳入2014年5月至2018年8月MRI检查发现85例经病理证实的胸腺肿瘤,结合MRI信号和形态学特征,借鉴乳腺BI-RADS分级模式,对病灶进行Ⅰ~Ⅴ类的分类诊断,并与WHO的组织细胞分类和Masaoka-Koga分期进行匹配对照。结果MRI分期与WHO分类和Masaoka-Koga分期可以形成较好的对应关系。根据病灶的信号和形态特征,85例胸腺肿瘤中,15/16例胸腺囊性病变被划分为Ⅱ类,对应良性病变;2/3例良性胸腺增生、4例A型、15/17例AB型、14/17例B1胸腺瘤被划分为Ⅲ类,对应低危病变;5/6例B2型和6例B3型胸腺瘤被划分为Ⅳ类,对应高危病变;9/11例胸腺癌被划分为Ⅴ类,对应侵袭性恶性病变。Spearmen相关系数为0.808,t=12.499,P<0.01。结论利用多模态MRI信息将胸腺肿瘤划分为Ⅰ~Ⅴ类,在一定程度上体现了WHO的组织学分型和Masaoka-Koga分期特征,有利于胸腺瘤的诊断治疗计划。

Objective:To explore the categorization of thymic tumors on MRI by using the similar mode of BI-RADS in breast diseases.Materials and Methods:From May 2014 to August 2018,85 cases of pathologically confirmed thymic tumors were examined by MRI.The lesions were categorized into Ⅰ-Ⅴ according to signal patterns and their morphological features with reference to WHO histopathological classification and Masaoka-Koga staging.Results:MRI categorization was well consistent with WHO classification and Masaoka-Koga staging.Of 85 cases of thymic tumors,15/16 cases of thymic cysts were category Ⅱ,indicating benign lesions;2/3 cases of benign thymic hyperplasia,4 cases of type A,15/17 cases of AB type,14/17 case B1 thymomas were category Ⅲ,indicating low-risk lesions;5/6 cases of type B2 and 6 cases of type B3 thymoma were category Ⅳ,indicating highrisk lesions;9/11 cases of thymic carcinoma were category Ⅴ,indicating invasive malignant lesions.The spearman correlation coefficient was 0.808,where t=12.499 and P<0.01.Conclusions:On the multiparametric MRI,the thymic tumors could be categorized into Ⅰ-Ⅴ as BI-RADS in breast lesions,which was well correlated to the WHO histopathological classification and the Masaoka-Koga staging and was helpful for the diagnosis and treatment plan of thymic lesions.