128排双源CT冠状动脉CTA成像多种扫描模式的应用

目的：探讨128排双源CT在冠状动脉CTA成像中多种扫描模式的应用价值。方法：603例临床表现为胸痛、胸闷且心率≤65次/分的患者行冠状动脉CTA。其中186例患者行前瞻性心电门控触发的超快速螺旋（FS）模式扫描；102例患者行前瞻性心电门控触发的序列（S）模式扫描；315例患者行回顾性心电门控触发的低螺距螺旋（LS）模式扫描，其中45例心律不齐。对3种扫描模式的辐射剂量进行方差分析，并对LS模式扫描的心律齐组与心律不齐组辐射剂量进行t检验。结果：FS、S及LS模式所获得的可评价冠状动脉段百分比相近，分别为99.4%、99.5%、99.2%；而不同模式扫描辐射剂量有明显差别，分别为（0.91±0.05） mSv、（5.48±0.95） mSv、（9.19±3.00） mSv，经方差分析两两比较，3组相互之间均有显著性差异（P值均<0.01）。LS模式扫描的患者中，心律齐者270例，心律不齐者45例，心律齐组与心律不齐组辐射剂量分别为（8.45±2.44） mSv、（13.62±2.09） mSv，经t检验，两组间有显著性差异（t=-13.428，P<0.01）。结论：128排双源CT冠状动脉成像3种（FS，S及LS）模式均能获得良好的图像质量，而FS模式辐射剂量显著低于S、LS模式，FS模式是实现低辐射剂量冠状动脉CTA的有效手段。根据受检患者心率、心律不同，采用不同的扫描模式，从而实现扫描方案最优化。

Coronary angiography by 128 multi-slice dual source CT with multiple scan modes

Objective： To evaluate the application of multiple scan modes in 128-slice dual-source CT coronary angiography.Methods： 603 patients of chest pain and chest tightness with heart rate ≤65bpm were examined by CT coronary angiography.186 patients were examined using the prospective ECG-gated flash spiral（FS） mode;102 patients were examined using the prospectively ECG-gated sequence（S） mode;315 patients were examined using the retrospective ECG-gated low-pith spiral（LS） mode,in which 45 cases had arrhythmia.The radiation dose of three modes was used for analysis of variance.The radiation dose was compared between the group of normal cardiac rhythm and the group of arrhythmia.Results： The percentage of diagnosable segments was similar with 99.4% for FS mode,99.5% for S mode and 99.2% for LS mode,but there was significant difference among three modes in radiation dose with（0.91±0.05） mSv for FS mode and（5.48±0.95） mSv for S mode and（9.19±3.00） mSv for LS mode（P0.01）.There were 270 patients of normal cardiac rhythm and 45 patients of arrhythmia in LS mode scanning,and there was significant difference in radiation dose with（8.45±2.44） mSv for the group of normal cardiac rhythm and（13.62±2.09） mSv for the group of arrhythmia（t=-13.428,P0.01）.Conclusion： The three modes（FS,S and LS） of 128-slice dual-source CT coronary angiography can obtain good image quality,but the radiation dose of FS mode were further significantly lower compared with S mode and LS mode.FS mode is an effective means to achieve low radiation dose for CT coronary angiography.Different scanning modes should be used according to the heart rate and rhythm of the patients to enable scan optimization.