256层CT冠状动脉造影中前瞻性心电门控技术的应用价值

  目的 通过比较256层CT前瞻性与回顾性心电门控冠状动脉造影的图像质量和辐射剂量，探讨前瞻性心电门控在冠状动脉造影中的应用价值和限度。方法 收集接受冠状动脉CT造影检查并采用前瞻性心电门控扫描者90例，采用回顾性心电门控扫描者103例。扫描时记录容积剂量指数及扫描野长度，计算剂量长度乘积和有效辐射剂量。所有患者均采用容积重建、曲面重建及多平面重建等后处理技术，对各冠状动脉节段的图像质量进行评分。结果 前瞻性心电门控扫描组和回顾性心电门控扫描组的平均心率分别为69次/min和78次/min，有效辐射剂量分别为（4.11±1.36）mSv和（12.10±5.62）mSv（P＜0.05），可评价率分别为94.1%和93.6%（P＞0.05）。结论 256层CT前瞻性心电门控冠状动脉造影的辐射剂量低，图像质量满意，应在心率符合扫描要求时最大限度的使用。

Application Value of Prospective ECG-gated 256-slice CT Coronary Angiography

Objective To explore the application value and limitation of prospective ECG-gated 256-slice CT coronary angiography by comparing image quality and patient radiation dose received by prospective ECG-gated scan with those obtained by retrospective ECG-gated scan.Methods A total of 193 cases were collected in this study.90 cases accepted prospective ECG-gated 256-slice CT coronary angiography(group A) and 103 cases accepted retrospective ECG-gated scan as a contrast group(group B).The CT dose index of volume,length of scan field were recorded immediately after scan and the dose length product and effective radiation dose(ED) were calculated.Post processing methods included volume rendering,curved planar reconstruction and multiplanar reconstruction.Each coronary segment was scored according to the post-processed image quality.Results The mean ED in group A with an average heart rate of 69 bpm was(4.11±1.36) mSv and that in group B with an average heart rate of 78 bpm(12.10±5.62) mSv.The evaluable rate in group A was 94.1% and that in group B was 93.6%.There was statistically significant difference in the mean ED(P < 0.05),but there was no statistical difference in the evaluable rate(P > 0.05) between group A and group B.Conclusion Prospective ECG-gated 256-slice CT coronary angiography could keep satisfactory image quality and reduce radiation dose.It should be used in clinic at the most if the heart rate adaptive.