目的 通过对胸痛三联征CT扫描 方案的优化及低管电压的使用，以期减少 对比剂的用量、降低辐射剂量。方法 将 临床怀疑胸痛三联征的34例患者随机分 为100KV和120KV两组，由心底向主动脉 弓方向的回顾性心电门控扫描模式。由两 位高年诊断医师对冠脉重建图像作主观评 分；测量两组资料肺动脉主干、降主动脉 和右冠起始部的CT值；计算三处图像信噪 比(SNR), 对比噪声比(CNR)和有效辐射剂 量(ED)，作统计分析。结果 图像主观评 分，肺动脉主干和降主动脉图像SNR没有 差异；肺动脉主干、降主动脉、右冠开 口处CT值，右冠开口图像SNR，肺动脉主 干、降主动脉、右冠开口处图像CNR，剂 量长度乘积和有效辐射剂量均有差异。结 论 改由心底向主动脉弓方向的胸痛三联 征扫描方式，同时采用低管电压既能保证 胸痛三联征的检查效果，实现对比剂、辐 射剂量的双低控制，具有较高的临床实际 应用价值。

Objective To optimize the Chest pain triad CT scan programs and the use of lower tube voltage to reduce the amount of contrast agent, reduce radiation dose. Methods divid the 34 cases Chest pain triad suspected by clinical were randomly into 100KV and 120KV two groups, using the direction of retrospective ECG-gated scan mode from bottom of heart to the aortic arch. Make subjective Evaluation for the reconstruction image of coronary by two high year diagnostic doctors, measuring the CT value of the two sets of data of pulmonary artery, the descending of aorta right coronary opening and right coronary artery beginning part, calculating the three images signal to noise ratio (SNR), calculating contrast noise ratio (CNR)and the effective radiation dose (ED), for statistical analysis. Results No difference in the coronary artery subjective scoring, pulmonary trunk and descending aorta SNR, pulmonary artery and the descending aorta and the opening of the right coronary CT value, right coronary artery opening image SNR, pulmonary trunk image and descending aorta image and right coronary artery opening image CNR, dose length product and effective radiation dose of the two sets data are different. Conclusion Change the scan direction from the heart bottom to the aortic arch for chest pain triad scan mode, while using low tube voltage can guarantee check the effect of the triad of chest pain, but also to achieve contrast and low radiation doses dual controlling, have more high clinical practical value.