前瞻性心电门控结合冠状动脉追踪冻结技术在高心率冠状动脉CT成像中的应用

Application of prospectively ECG-gating combined with snapshot freeze of coronary CT angiography in high heart rate patients

目的探讨前瞻性心电门控结合冠状动脉追踪冻结（SSF）技术对快心率患者降低辐射剂量及保证图像质量的价值。方法60例患者接受前瞻性心电门控扫描,心率为73-80次/分。根据患者体质量指数选择管电流为230-750mA,管电压为100-120kV。扫描后分别采用SSF重建及不采用SSF重建。计算患者的有效剂量（ED）,并将其与回顾性心电门控螺旋扫描参数模拟计算的ED进行对比。采用美国心脏学会冠状动脉分段方法对其图像质量评分。结果前瞻性心电门控结合SSF技术与不结合SSF技术的冠状动脉图像质量评分分别为（3.41±0.59）分和（2.55±1.45）分（P〈0.05）。前瞻性心电门控结合SSF技术与回顾性心电门控成像的ED分别为（4.86±0.80）mSv和（15.80±2.50）mSv（P〈0.05）。结论前瞻性心电门控结合SSF技术可明显减少辐射剂量,并同时获得满足临床诊断需要的图像质量。

Objective To evaluate the value of coronary CT angiography（CCTA）prospectively ECG-gating combined with snapshot freeze（SSF）on improving image quality and reducing radiation does in high heart rate patients.MethodsTotally 60 patients with heart rate 73—80bpm underwent CCTA using the prospectively ECG-gating combined with SSF.Tube voltage（100—120kV）and tube current（230—750 mA）were selected based on patient body mass index.Images were reconstructed respectively with SSF or without SSF after scanning.Effective dose（ED）of prospectively ECG-gating combined with SSF were calculated and compared with the standard protocols using retrospective gating mode.Image quality were scored using the American Heart Association guideline.Results The image quality score of CCTA prospectively ECG-gating combined with SSF was 3.41±0.59,and without SSF was 2.55±1.45,difference had statistical significance（P〈0.05）.ED of CCTA prospectively ECG-gating combined with SSF was（4.86±0.80）mSv and without SSF was（15.80±2.50）mSv（P〈0.05）.Conclusion CCTA prospectively ECG-gating combined with SSF for high heart rate patients can ensure clinically acceptable image quality and reduce radiation dose.