CT增强扫描鉴别诊断肺内孤立小结节价值

Solitary Pulmonary Nodules: Evaluation with Incremental Dynamic CT

目的：评价ＣＴ增强扫描鉴别诊断肺内孤立小结节的价值。材料与方法：直径８-２０ｍｍ肺内孤立小结节患者２６例：小肺癌１２例，灶性肺炎７例，结核结节４例，硬化性血管瘤１例，错构瘤２例．增强扫描前后均行薄层扫描（１．５－５ｍｍ层厚）．分别进行 ＣＴ平扫及 ＣＴ增强诊断的前瞻性对比研究结果： ＣＴ平扫诊断正确率为 ６５％， ＣＴ增强后诊断正确率为７７％，二者无显著差异。小肺癌、灶性肺炎及肺结核结节的平均增强ＣＴ值分别为４２Ｈｕ，３７Ｈｕ和３Ｈｕ。１例错构瘤和１例血管瘤因增强ＣＴ值大于４０Ｈｕ而误诊为肺癌。结论：ＣＴ增强对肺结核结节的诊断有帮助，肺癌和肺炎性病灶的ＣＴ增强鉴别诊断有困难。应强调以病灶基本形态为依据，增强ＣＴ对鉴别诊断有价值。１．０ｃｍ以下病灶的ＣＴ值测量不准确。

Purpose: To evaluate the differential diagnostic value of incremental dynamic CT in small SPNs. Materials and Methods: Twenty-three adult patients with SPNs less than 2-cm in diamater had 12 primary lung cancers, 7 focal pneumonias, 4 nodular tuberculomas, 2 hamartomas and 1 sclerosing hemangioma. Thin-section CT was performed before and after administration of contrast material. Correlative Study of conventional and incremental CT diagnosis had been done prospectively. Results: The accuracy of conventional CT diagnosis was 65%, and 77% after administration of contrast material. and no significnt difference was seen statistically between conventional and incremental CT diagnosis (p>0. 05). The mean enhanced CT values of small lung cancers, focal pneumonias and nodular tuberculosis were 42Hu, 37Hu and 3Hu, respectively. One hamartoma and one sclerosing hemangioma were diagnosed wrongly because of significant enhancement more than 40Hu. Conclusion: It's helpful to differentiate nodular tuberculosis from small lung cancer with incremental CT, and difficult to distinguish small lung cancers from inflammatory lung diseases only according to the degree of enhancement. We emphasize that incremental CT was important to differentiate small malignant SPNs from benign ones on the basis of morphology, and find that CT values of SPNs less than 1-cm in diamater couldn't be measured accurately.