MSCT增强扫描方式的优化对肺孤立小结节的诊断价值

目的:探讨MSCT肺部3期增强扫描方式对肺部孤立性小结节(SPN)的诊断价值。方法:收集30例应用改进的增强扫描方式(即3期扫描)检查的SPN患者的影像资料。3期扫描包括动脉期30 s,静脉期60 s,平衡期120 s,分析SPN的强化程度及增强方式,并绘制时间-密度曲线。结果:通过曲线首尾两点做直线,对照发现,代表慢性炎症的直线斜率要大于代表肺癌的直线斜率。肺癌和慢性炎症通过肺3期增强扫描,CT值增长幅度较大,肺癌增强扫描后最大增长值平均为25 HU,且一般会均匀强化,慢性炎症为35 HU,且一般为周边强化明显;结核增长幅度不大,平均为10.9 HU,且一般中央不强化。结论:通过3期增强扫描,结核比较容易区分,而肺癌和慢性炎症因为增长幅度都较大,增强CT值之间有交叉,所以通过时间-密度曲线首尾两点做直线,其斜率可对慢性炎症和肺癌进行鉴别诊断。

Diagnostic value of the optimization of MSCT scanning modes on the small solitary pulmonary nodules

Objective：To explore the diagnostic value of MSCT scanning mode with three-phases contrast enhancement on the small solitary pulmonary nodules （SPN）. Methods： Thirty cases of small solitary pulmonary nodules confirmed by pathology were examined by the modified MSCT scanning modes with 3 phases contrast enhaneement,includlng pulmonary carcinoma （18 cases） .puhnonary mherculosis （7 cases） and chronic infective nodules （5 cases）. The times of 3 phases contrast enhancement were 35 sec （arterial phase） .60 scc （venous phase） and 120 sec （balance phase） after the injection of the contrast medium. The enhaneed degree and style were observed and the time-density curves were drawn. Results：The carcinoma and chronic infective nodules had big extent of CT value increase on the scans of the 3 phase contrast enhancement. The average increase of CT value in carcinoma was 25 HU and the enhanced style was homogeneous enhancement. Pulmonary tuberculosis had a small average increase of CT value, which was only 10, 9HU and the lesions generally had not any enhancement in central area. The average increase of CT value in chronic infective nodules was 35HU and the enhancement style was obviously peripheral enhancement. The linear slope rate of the time density curve from the chronic infective nodules was higher than that from pulmonary carcinoma. Conclusion：Three phase eontrast enhancement can distinguish the pulmonary tuberculosis and carcinoma. The pulmonary carcinoma and chronic infective nodules both show obvious increase of CT value after 3 phase contrast enhanced scanning. But the differentiation between them can be made by the different linear slope rates of the time-density curves.