孤立性肺结节的增强CT表现及鉴别诊断

Solitary pulmonary nodules: CT appearance and differentiation of enhancement with contrast medium

目的 探讨良恶性孤立性肺结节(solitary pulmonary nodule,SPN)的增强CT表现及鉴别诊断价值。方法 对75例经手术、病理证实的SPN患者的CT图象进行回顾性分析,其中恶性肿瘤59例,良性肿瘤8例,肉芽肿8例。所用CT为Siemens SomatomPlus,采用病灶中心层面同床位动态扫描模式,测注射造影剂前后相同层面的CT值,以30Hu作为结节造影后有强化的下限。结果 本组中无强化9例,有强化66例。按强化程度分:轻度强化35例,中度强化27例,显著强化4例;按强化形态分:均匀强化38例,不均匀强化21例,周边强化7例;按病变性质分:恶性肿瘤多呈轻。中度均匀或不均匀强化,肺腺瘤和炎性假瘤多呈中度均匀强化,肺错构瘤和结核瘤多元强化或仅是边缘强化,肺血管瘤(包括动静脉畸形)表现为显著均匀强化。结论 良恶性SPN因部位、大小、血供及细胞类型等的差异而呈现不同的强化特征。

I Purpose To evaluate enhanced appearances and establish differential diagnosis of solitary pulmonary nodules(SPNs) with contrast medium. Methods Seventy- five patiens(53 men, 22 women) with SPN confirmed by surgery and pathology were retrospectively studied. In all cases, dynamic CT scanning had been performed before and after intravenous administration of contrast medium and the density values of lesions were measured in Hounsfield unit. The patterns of enhancement were analyzed in all patients. 30HU was set as the lowest threshold of enhancement. Results there are 66 enchanced nodules and 9 unenchanced in 75 SPNs. According to the enhancement patterns, even enhancement appeared in 38 nodules, uneven enhancement in 21 and edge enhancement in 7. Considering the enhancement degrees, there were 35 mild enhancement nodules, 27 moderate and 4 marked. In view of different biological and pathological characteristics, malignant tumors showed mild or moderate and even or uneven enhancement. Pulmonary adenomas and inflammatory pseudotumors demonstrated moderate and even enhancement. Pulmonary hamartomas and tuberculomas had no enhancement or edge enhancement only. The vascular tumors including artery- vein malformation(AVM)had marked and even enhancement. Conclusion since the different characteristics of location,size, vascularity and cytology of malignant and benign nodules, SPNs show different enhancement patterns and degrees with contrast scanning.