CT支气管征在鉴别良恶性实性孤立性肺结节(≤2 cm)中的价值

Value of bronchogram sign on CT images in differentiating benign and malignant solid pulmonary nodules with maximum diameter ≤2 cm

目的探讨最大径≤2 cm的实性肺结节与支气管的关系,以期为良恶性肺结节的鉴别诊断提供线索。方法回顾性分析本院2014年1月至2021年1月经手术病理证实的776例最大径≤2 cm实性肺结节患者的临床及CT资料,根据病理结果分为恶性结节组(340例)和良性结节组(436例),良性结节组又分为炎性结节组(299例)和良性肿瘤组(137例)。根据肺结节与支气管的关系将CT支气管征分为4型,分别比较恶性结节组和良性结节组、炎性结节组和良性肿瘤组CT支气管征的发生率及其分型的差异,评估CT支气管征对良、恶性实性肺结节的诊断效能。结果(1)恶性结节组CT支气管征发生率为65.9%(224/340),显著高于良性结节组(31.4%,P<0.001);良性结节组Ⅰ型、Ⅱ型CT支气管征发生率显著高于恶性结节组,而恶性结节组Ⅲ型、Ⅳ型CT支气管征发生率显著高于良性结节组,差异均有统计学意义(P<0.01);CT支气管征鉴别良恶性实性肺结节的灵敏度为82.1%,特异度为56.2%,准确率为72.3%。(2)炎性结节组CT支气管征发生率为39.1%(117/299),显著高于良性肿瘤组(14.6%,P<0.001);炎性结节组Ⅳ型CT支气管征发生率显著高于良性肿瘤组(P<0.05),而两组Ⅰ型、Ⅱ型及Ⅲ型CT支气管征发生率差异均无统计学意义(P>0.05)。结论CT支气管征对鉴别最大径≤2 cm实性孤立性肺结节的良恶性有一定价值,当肺结节内出现不规则充气支气管征或支气管走行至结节边缘截断时需高度警惕肺癌的可能。

Objective To investigate the relationship between solid pulmonary nodules with maximum diameter≤2 cm and the bronchi in order to provide more valuable clues to differentiate benign and malignant solid pulmonary nodules.Methods The clinical and CT data of 776 patients with solid pulmonary nodule at a maximum diameter of not larger than 2 cm confirmed by pathology in our hospital from January 2014 to January 2021 were analyzed retrospectively.According to pathological types,the patients were divided into malignant nodule group(n=340)and benign nodule group(n=436),and those with benign nodules were further assigned into inflammatory nodule subgroup(n=299)and benign tumor subgroup(n=137).Bronchogram sign on CT images were classified into 4 types according to the relationship between pulmonary nodules and bronchi.The incidence and types of different bronchogram sign on CT images were compared between malignant nodule group and benign nodule group,and between inflammatory nodule subgroup and benign tumor subgroup.The diagnostic performance of bronchogram sign on CT images to differentiate benign and malignant solid pulmonary nodules was evaluated.Results(1)The incidence of bronchogram sign on CT images was higher in the malignant nodule group than the benign nodule group(65.9%vs 31.4%,P<0.001).TypesⅠandⅡsigns were more common in the benign nodule group,while TypesⅢandⅣsigns were more common in the malignant nodule group(all P<0.01).The sensitivity,specificity,and accuracy of bronchogram sign on CT images was 82.1%,56.2%,and 72.3%,respectively in differentiation of benign and malignant solid pulmonary nodules.(2)The incidence of bronchogram sign on CT images was statistically higher in the inflammatory nodule subgroup than the benign tumor subgroup(39.1%vs 14.6%,P<0.001).TypeⅣwas more common in inflammatory nodule subgroup(P<0.05).However,no significant differences were observed in the other 3 types between the 2 subgroups(all P>0.05).Conclusion Bronchogram sign on CT images is valuable in differentiation of benign and malignant solid pulmonary nodules measuring≤2 cm in diameter.Irregular air bronchogram sign or truncation of bronchus in the margin of nodule is highly suggestive of malignancy.