目的 探讨能谱CT成像结合低浓 度对比剂在冠状动脉CT血管成像(CCTA)中 的临床应用价值。方法 选取2016年1月至 2月期间怀疑冠状动脉病变而接受CCTA检 查的75例患者，随机分为A组和B组，A组 使用对比剂碘浓度为300mg/mL，能谱低 剂量扫描模式，B组使用对比剂碘浓度为 370mg/mL，管电压120kV，比较两组左冠 状动脉主干(LM)、左前降支近段(LAD),右 冠状动脉(RCA)的CT值，计算信噪比(SNR) 和对比噪声比(CNR)，评价图像质量等。 结果 A组容积CT剂量指数(CTDIvol)、 有效辐射剂量(ED)和碘摄入量分别为 (32.08±3.12)mGy、(10.51±2.03)mSv 和(13.86±1.09)g，较B组明显降低(P ＜0.05）；A组图像噪声为(24.12±2.27) HU，明显高于B组(P＜0.05)；A组患者 LM、LAD、RCA近段管腔的CT值分别为 (480.15±52.08)HU、(460.15±60.14) HU、(455.13±60.42)HU，明显高于B组 (P＜0.05)；两组LM、LAD、RCA近段管腔 的SNR、CNR比较差异无统计学意义(P＞ 0.05)；两组图像质量节段评分差异无统 计学意义(P＞0.05)；图像质量等级评分 一致性良好，Kappa值=0.783，P＜0.05。 结论 能谱CT成像结合低浓度对比剂行冠 状动脉检查，能获得满意的图像质量，并 能显著降低辐射剂量和碘摄入量。

Objective To investigate clinical application value of spectroscopy CT imaging combined with low concentrations contrast agent in coronary artery CT angiography(CCTA). Methods During the period from January to February 2016 due to the clinical suspicion of coronary artery lesions underwent CCTA examinations of 75 patients, were randomly divided into A group and B group, A group using iodine contrast agent concentration was 300mg/mL, the tube voltage 100kV, B group using iodine contrast agent concentration was 370mg/mL, voltage 120kV, compared two groups left main coronary artery (LM) and proximal left anterior descending (LAD), right coronary artery (RCA) CT value, calculated the signal-to-noise ratio (SNR) and contrast to noise ratio (CNR), image quality evaluation etc. Results Group A, volume CT dose index (CTDIvol), effective radiation dose (ED) and iodine intake respectively (32.08±3.12) mGy, (10.51±2.03) mSv and (13.86±1.09) g, significantly lower than B group (P<0.05). A group image noise (24.12±2.27) HU, significantly higher than group B (P<0.05). A group patients LM, LAD, RCA proximal lumen CT value were (480.15±52.08) HU, (460.15±60.14) HU, (455.13±60.42) HU, significantly higher than group B (P<0.05). Two group LM, LAD, RCA proximal lumen SNR, CNR difference was not statistically significant (P>0.05), two group image quality segment score difference was not statistically significant (P>0.05), good image quality scoring consistency, Kappa value=0.783, P<0.05. Conclusion Spectroscopy CT imaging combined with low concentrations of contrast agent in coronary angiography, can obtain satisfactory image quality, and can significantly reduce radiation dose and iodine intake.