动态增强CT时间密度曲线参数在肺部孤立性结节良恶性鉴别中的应用

Application of dynamic enhanced CT time density curve in differential diagnosis of benign or malignant solitary pulmonary nodules

目的探讨在肺部三期强化检查中,由时间密度曲线归纳出的参数——主动脉期(23 s)与延迟期(90 s) CT值差值(绝对值)能否在强化峰值的基础上进一步区分孤立性肺部结节(或团块)的良恶性。方法回顾性分析38例有病理结果的肺部孤立性结节或团块三期(13 s、23 s、90 s) CT强化图像,测量其ROI(感兴趣区)的CT值,分别计算强化峰值与主动脉期(23 s)与延迟期(90 s) CT值差值。在排除无明显强化的病例(强化峰值<15 Hu)后,以t检验分析剩余的肺癌与炎性病例的主动脉期、延迟期CT值差值差异是否有统计学意义。结果在排除无明显强化的病例(强化峰值<15 Hu)后,肺癌与炎性病例的主动脉期、延迟期CT值差值有统计学差异(P=0. 002)。以强化峰值> 15 Hu作为判断恶性SPN(或团块)的阈值时,灵敏度为100%,特异度为28. 6%。以强化峰值> 15 Hu且主动脉期、延迟期CT值差值<20 Hu作为判断恶性SPN(或团块)的标准时,特异度可提升至84. 2%。结论大部分恶性SPN强化曲线的流出期表现为平台型,而炎性SPN通常为表现为持续上升或速升速降。在肺部三期强化检查中,主动脉期、延迟期CT值差值可以在强化峰值的基础上进一步区分孤立性肺部结节(或团块)的良恶性,有一定的临床应用价值。

Objective To investigate the application value of dynamic enhanced CT time density curve--the difference of CT value(absolute value)between the aortic phase(23s)and the delayed phase(90s)in differential diagnosis of benign or malignant solitary pulmonary nodules(masses)on the basis of the peak value of pulmonary three phases enhanced examination.Methods The CT enhancement images of 38 patients with solitary pulmonary nodules(SPN)or masses in three phases(13s,23s,90s)were retrospectively analyzed,and all the patients had been pathologically examined.CT values of ROI(region of interest)were measured,and the CT values of enhancement peak value,and the difference value between aortic phase(23s)and delayed phase(90s)were calculated respectively.After excluding the cases without obvious enhancement(enhancement peak<15Hu),the CT differnce values at aortic period and delayed period between the patients with lung cancer and the patients with inflammation were observed and statistically analyzed.Results After excluding the cases without obvious enhancement(the enhancement peak<15Hu),there were significant differences in the CT differnce values at aortic period and delayed period between the patients with lung cancer and the patients with inflammation(P<0.01).Taking the enhancement peak >15Hu as the threshold value of malignant SPN(or mass),the sensitivity was 100%and the specificity was 28.6%,however,taking the enhancement peak >15Hu and the CT difference value<20Hu between aortic phase and delayed phase as the criteria to judge malignant SPN(or mass),the specificity could reach 84.2%.Conclusion The outflow phase of most malignant SPN shows a platform,however,most inflammatory SPN shows a elevating or mountain peak form.The CT difference value between aortic phase and delayed phase can further distinguish the benign or malignant of SPN(or masses)on the basis of the enhanced peak value in three phase pulmanary enhancement examination,thus,which has a certain clinical application value.