CT环状钙化鉴别甲状腺结节良恶性的价值

The value of CT annular calcification in identifying benign and malignant thyroid nodules

目的 评价CT环状钙化在甲状腺良恶性结节诊断和鉴别诊断中的价值.方法 回顾性分析经手术病理证实并具有环状钙化的67例67枚甲状腺结节的CT资料,49枚为良性结节,18枚为恶性结节.对比增强前后环状钙化内部或周围边界,观察环状钙化内部与甲状腺组织的强化程度.统计良、恶性结节中出现增强后边缘清晰、高强化的病灶数,并采用x2检验进行统计学分析.结果 67枚环状钙化结节中,增强后边缘清晰在良性结节和恶性结节中分别占61.2％（30/49）和16.7％（3/18）,差异有统计学意义（x2=10.457,P＜0.05）,其诊断良性结节的敏感度和特异度分别为61.2％（30/49）和83.3％（15/18）.高强化在良性结节和恶性结节分别为16.3％（8/49）和0（0/18）,差异无统计学意义（x2=3.337,P＞0.05）,诊断敏感度和特异度分别为16.3％（8/49）和100.0％（18/18）;增强后边缘清晰和高强化联合在良性结节和恶性结节中分别为77.6％ （38/49）和16.7％（3/18）,差异有统计学意义（x2=20.549,P＜0.05）,诊断敏感度和特异度分别为77.6％（38/49）和83.3％ （15/18）.结论 CT在甲状腺结节环状钙化的诊断中具有重要价值,增强后边缘清晰及高强化与增强后边缘清晰的联合应用有助于良性结节的诊断,增强后边缘相仿或模糊提示恶性结节的诊断.

Objective To evaluate the value of annular calcification in CT in the diagnosis and differential diagnosis for benign and malignant thyroid nodules.Methods CT findings of 67 nodules in 67 patients pathologically diagnosed with annular calcifications were retrospectively analyzed to identify 49 benign nodules and 18 malignant nodules.The interior or boundaries of annular calcification before and after contrast-enhancement were compared,and the degree of enhancements of both interior annular calcification and thyroid tissues were observed.After contrast-enhancement,the numbers of lesions showing clearer boundaries and higher degree of enhancement were summarized.Statistic analysis was conducted by using x2 test.Results Among 67 nodules with annular calcifications,clearer boundaries after contrast-enhancement were observed in 61.2％ （30/49） benign nodules and 16.7％ （3/18） malignant nodules,showing significant statistical difference （x2 =10.457,P ＜ 0.05）.The sensitivity and specificity of clearer edge after contrast-enhancement for benign nodules were 61.2％ （30/49） and 83.3％ （15/18） respectively.Higher degree of enhancement were observed in 16.3％ （8/49） in benign nodules and 0（0/18） malignant nodules,showing no significant statistical difference （x2 =3.337,P ＞ 0.05）.The sensitivity and specificity of higher degree of enhancement for benign nodules were 16.3％ （8/49） and 100.0％ （18/18） respectively.The combination of clearer boundaries and higher degree of enhancement after contrast-enhancement was observed in 77.6％ （38/49） benign nodules and 16.7％ （3/18） malignant nodules,showing significant statistical difference （x2 =20.549,P ＜ 0.05）.Meanwhile,the sensitivity and specificity of such combination for benign nodules were 77.6％ （38/49） and 83.3％ （15/18） respectively.Conclusions CT is important in the diagnosis of thyroid nodules with annular calcification.Clearer boundary after contrast-enhancement and its combination with higher degree of enhancement are helpful for the diagnosis of benign nodules.Boundaries that similar to or more obscure than that of plain scan indicate malignant nodules.