低剂量、低对比剂肺动脉CTA技术在肺栓塞诊断中的可行性研究

Feasibility study of pulmonary embolism with low dose and low contrast agent CTA in pulmonary embolism

目的:探讨低剂量、低对比剂肺动脉计算机体层血管成像(CTA)技术在肺栓塞诊断中的应用准确性。方法:选取100例经病理结果证实的肺栓塞患者作为研究对象,根据检查方法分为试验组50例和常规组50例,对比两种方法下肺动脉栓塞诊断阳性率差异,利用5分法对两组图像进行主观评价,通过噪声值、图像信噪比(SNR)、对比噪声比(CNR)、容积CT剂量指数(CTDI_(vol))和剂量长度乘积(DLP)差异进行客观评价。结果:常规组中,共诊断肺动脉栓塞50例,诊断右肺栓塞12例,左肺栓塞10例,肺上叶栓塞8例,肺下叶栓塞14例,双肺同时栓塞6例;试验组中,共诊断肺动脉栓塞45例,其中右肺栓塞11例,左肺栓塞9例,肺上叶栓塞7例,肺下叶栓塞13例,双肺同时栓塞5例。两组间肺动脉栓塞阳性检出率差异无统计学意义(P> 0.05);试验组和常规组图像均能显示四到六级分支,试验组主观得分(4.12±0.60)分,常规组主观得分(4.38±0.72)分,组间图像质量评分差异无统计学意义,且2名阅片者间评分具有良好的一致性(试验组ICC=0.910,常规组ICC=0.970,P<0.05)。试验组噪声高于常规组,SNR、CNR、CTDI_(vol)及DLP低于常规组,差异均有统计学意义(P<0.05)。结论:低剂量、低对比剂肺动脉CTA技术可以作为肺栓塞疾病诊断方式之一,通过该技术手段的实施,能够在降低辐射剂量和减少对比剂剂量的同时,显示四至六级肺动脉分支,且对肺动脉栓塞的诊断阳性率与常规CTPA技术一致,值得临床应用及推广。

Objective To explore the accuracy of low-dose and low-contrast pulmonary artery CTA in the diagnosis of pulmonary embolism.Methods 100 patients with pulmonary embolism confirmed by pathology were divided into experimental group(n=50) and routine group(n=50).The positive rate of pulmonary embolism was compared between the two groups.5-score method was used to subjectively evaluate the images of the two groups.The differences of noise value,image signal-to-noise ratio(SNR),contrastto-noise ratio(CNR),volume CT dose index(CTDI_(vol)) and dose length product(DLP) were objectively evaluated.Results In the routine group,50 cases of pulmonary embolism were diagnosed including 12 cases of right pulmonary embolism,10 cases of left pulmonary embolism,8 cases of upper lobe embolism,14 cases of lower lobe embolism and 6 cases of simultaneous pulmonary embolism;and 45 cases of pulmonary embolism were diagnosed in the experimental group,there were 11 cases of right pulmonary embolism,9 cases of left pulmonary embolism,7 cases of upper lobe embolism,13 cases of lower lobe embolism and 5 cases of simultaneous pulmonary embolism.There was no significant difference in the positive rate of pulmonary embolism between the two groups(P> 0.05).The subjective scores of the experimental group and the routine group were(4.12±0.60) and(4.38±0.72).There was no significant difference in image quality between the two groups,and the scores of the two readers were consistent(ICC=0.910in the experimental group and ICC=0.970 in the routine group,P <0.05).The noise in the experimental group was higher than that in the routine group,and the levels of SNR,CNR,CTDI_(vol) and DLP in the experimental group were significantly lower than those in the routine group.Conclusion Low-dose and low-contrast pulmonary artery CTA technique can be used as one of the diagnostic methods of pulmonary embolism.Through the implementation of this technique,it can display the fourth to sixth grade pulmonary artery branches while reducing the radiation dose and contrast medium dose,and the diagnostic positive rate of pulmonary embolism is consistent with that of conventional CTPA,which is worthy of clinical application and promotion.