目的 分析对比光子双源CT两种 模式肺动脉血管成像的诊断价值。方法 抽选本院2011年5月-2015年7月收治的可 疑肺栓塞男性患者80例，随机均分为A组 和B组，A组行双能量肺动脉成像，B组以 Flash模式成像，图像重建均采用迭代重 建技术算法。比较两组患者CT值、噪声 (SD)、信噪比(SNR)、对比信噪比(CNR) 及CT容积剂量指数(CTDIvol)、有效剂量 长度乘积(DLP)、有效辐射剂量(ED)。 结果 A组患者图像CT值(364.2±63.7) Hu较B组(643.5±91.4)Hu显著较高， SD(20.4±3.9)Hu较B组(37.1±4.6)Hu显 著较低(P<0.05)；两组不同ROI的SNR、 CNR值比较差异无统计学意义(P>0.05)； B组CTDIvol、DLP、ED较A组显著较少 [(1.67±0.32)mGy、(54.24±5.91)mGym. cm、(0.63±0.09)mSvTVS(8.43±1.06) mGy、(250.41±51.60)mGym·cm、 (3.27±0.62)mSvT](P<0.05)。结论 双源 CT Flash模式结合迭代重建技术与双能量 扫描模式比较不仅能满足图像诊断要求， 还能降低辐射剂量。

Objective To analyze and compare the diagnostic value of two modes of photonic dual source CT pulmonary angiography. Methods A total of 80 cases of male patients with suspected pulmonary embolism who were treated in our hospital between May 2011 and July 2015 were selected and were randomized into group A and B. Group A underwent dual energy pulmonary angiography while group B underwent Flash mode imaging. Iterative reconstruction algorithm was used for image reconstruction. The CT values, noise (SD), signal to noise ratio (SNR), contrast noise ratio (CNR) and CT dose index volume (CTDIvol), effective dose length product (DLP) and effective radiation dose (ED) were compared between the two groups. Results The CT value of image of patients in group A (364.2±63.7) Hu was significantly higher than that in group B (643.5±91.4) Hu while SD (20.4±3.9) Hu was significantly lower than that in group B (37.1±4.6) Hu (P<0.05). There were no significant differences in SNR and CNR values between different ROI in the two groups (P>0.05). The CTDIvol, DLP and ED of group B was significantly less than that of group A [(1.67±0.32) mGy, (54.24±5.91) mGym.cm, (0.63±0.09) mSvT VS (8.43±1.06) mGy, (250.41±51.60) mGym·cm, (3.27±0.62) mSvT] (P<0.05). Conclusion The comparison of dual source CT Flash mode combined with iterative reconstruction technique and dual energy scan mode not only can meet the requirement of image diagnosis, but also can reduce the radiation dose.