目的 探讨基于瘦体重的对比剂 注射方案在冠状动脉CT血管造影中血管 增强效果是否优于基于体重的方案。方 法 200例进行冠状动脉CT血管造影扫描 的患者随机分成两组，分别采用不同的 对比剂用量计算方案：体重组采用体重 乘以系数计算，瘦体重组利用测量得到 的瘦体重乘以标准化的系数计算，每例 患者对比剂注射持续时间等于扫描时间 ＋8秒。测量两组间冠状动脉开口处的升 主动脉、左冠状动脉主干、左前降支、 左回旋支及右冠状动脉的血管内CT值， 比较两组间各血管内CT值离均差绝对值 的差异，并分析各组内升主动脉CT值和 计算对比剂剂量的体型参数的相关性。 结果 1、两组各血管内CT值的平均值的 差异无统计学意义。2、体重组各血管 内CT值的离均差绝对值显著大于瘦体重 组。3、体重组肥胖患者中各血管内CT值 的平均值显著大于瘦体重组。结论 利用 瘦体重计算CCTA检查中对比剂的用量的 方案，其血管增强效果的均一程度优于 根据体重确定对比剂用量的方法。

Objective To compare the effect of coronary enhancement at coronary CT angiography using contrast material injection protocol with dose adjusted to LBW with using protocols adjusted to total body weight. Methods A total of 200 consecutive patients undergoing DSCT CCTA without previous coronary stent placement, bypass surgery, congenital or valvular heart disease were included, and were randomly assigned to two groups. The contrast material dose of two groups were calculated by total body weight in TBW group and by measured lean body weight in LBW group. The injection durations of both groups were determined by using scan time plus 8 seconds divided total contrast material dose. Postcontrast attenuation measurements were obtained in AA above the coronary ostia, LM, LAD, LCX and RCA for each group. Mean absolute deviation were calculated in two group and analyzed. Results 1.The mean attenuations of AA, LM, LAD, LCX and RCA shows no significant differences between two groups. 2. The mean absolute deviation of aortic and coronary attenuation in TBW group was higher than the LBW group, and the result shows statistical significant. 3.Compare with nonobese patients, the aortic and coronary attenuations in obese patient were lower in TBW group. Conclusion By employing the lean body weight to calculate the contrast material dose needed for CCTA, it may lessen patient-to-patient enhancement variability while maintaining satisfactory aortic and coronary enhancement.