第2代双源CT冠状动脉个性化扫描方案效果评价

目的探讨第2代双源CT的三种扫描模式在不同心率、心律患者冠状动脉检查的应用效果，比较其图像质量和扫描剂量。方法根据不同心率、心律将166例冠状动脉检查者分为A、B、C组（A组：平稳低心率组，B组：平稳高心率组，C组：不稳定心律组），分别行炫速双源CTHash、Sequence或Routine扫描模式检查，记录扫描时的心率、心率变异幅度，和扫描剂量，并评价冠脉三支主干的图像质量（0～3分）。结果Flash法扫描患者67例，平均扫描剂量为（0．73±0．09）mSv；Sequence法扫描35例，平均扫描剂量为（3．73±1．27）mSv；Routine法扫描64例，平均扫描剂量为（9．07±2．96）mSv，三种扫描模扫描剂量差异有统计学意义（P〈0．01）。三种扫描模式下，各支冠状动脉主干的图像质量差异无统计学意义（P〉0．05）。心率和图像质量有相关性（P〈0．01），而心率变异幅度与前降支的图像质量有相关性（P〈0．01），与回旋支和右冠状动脉的图像质量无相关性（P〉0．05）。结论第2代双源CT能依据患者的心率、心律情况进行个性化选择冠脉CT扫描模式，在保证较高的图像质量的同时可以最大程度降低患者的扫描剂量。

Different scan modes of 2nd-generation dual-source CT for CT coronary angiography

Objective To evaluate the application of three scan modes for CT coronary angiography by using 2nd-generation dual source CT. Methods One hundred and sixty six patients underwent CT coronary angiography with 2nd-generation dual source CT scanner （DSCT： SOMATOM Definition Flash）, among them 67 patients （ HR 〈 70 bpm with regular rhythm） were examined with flash scan mode, 35 patients （HR ≥ 70 bpm with regular rhythm） with sequence scan mode, and 64 patients （irregular rhythm） with conventional spiral mode, respectively. The radiation dose and image quality of three main coronary artery branches of these scan modes were compared. Results The average doses used for flash, sequence and conventional scan modes were （0.73±0.09 ）, （3.73±1.27 ） and （9.07±2.96）mSv, respectively （P 〈 0.01 ）. There were no significant differences in the imagequality of three main branches of coronary arteries among 3 different scan modes （ P 〉 0. 05 ）. The image quality was significantly correlated with heart rate （ P 〈 0.01 ）. The variation of heart rate was correlated with the image quality of LAD （P 〈 0.01 ）, but not correlated with that of LCX and RCA （P 〉0.05）. Conclusion The scan mode of 2hal-generation DSCT image can be chosen according to heart rate and rhythm of patients to achieve satisfactory imaging quality and low radiation dose.