直接屏气方式对64层CT冠状动脉造影的影响

目的：评价平静呼吸下直接屏气法对64层螺旋CT冠状动脉造影成功率的影响。方法：69例患者应用SIEMENS SOMATOM Sensation 64层螺旋CT进行冠状动脉造影，扫描时采用平静呼吸下直接屏气的方式。采集的原始图像采用容积再现技术（VRT），多平面重建（MPR），曲面重建（CPR）和最大密度投影（MIP）等，对冠状动脉主要分支（RCA、LM、LAD、LCX）图像采用双盲法进行评估。结果：通过采用平静呼吸下直接屏气，根据心率不同分为四组。A组：心率为≤60次／分，心率波动为1～3次／分，95．8％（92／96）的图像符合诊断要求；B组：心率为61-70次／分，心率波动为1-4次／分，93．3％（97／104）的图像符合诊断要求；c组：心率为在71—80次／分，心率波动为1—4次／分，87．5％（49／56）的图像符合诊断要求；D组：心率≥81次／分，心率波动为2—5次／分，33．3％（4／12）的图像符合诊断要求。结论：应用64层螺旋CT进行冠状动脉造影，采用平静呼吸下直接屏气降低多数患者的心率和减少其心率波动．从而提高检杳的成功率。

Effect of direct breath holding on coronary angiography with 64-slice CT scanner

Objective：To evaluate the influence of direct breath bolding at eupnea on achievement ratio of coronary angiography with （M-slice CT scanner. Methods： Used SIEMENS SOMATOM Sensation 04-slice spiral CT, coronary angiograpby on direct breath holding at eupnea were performed in 69 patients with heart diseases. Images were retrospectively reconstructed under different reformations in teerms of volume rendering technology （VRT）, multi-planar reconstruction （MPR）, curved planar reconstruction（CPR）, and maximum intensity projection（MIP）. The images of coronary artery were evaluated by double blind method. Results：According to heart rate, all the branch images were divided into four different groups in patients with direct breath holding at eupnea. Group A： with heart rote ≤ 60 bpm and heart rate fluctuations 1 - 3 bpm, tbe 95.8% （92/96） of images for the diagnostic requirements were got; Group B： with heart rate 61 - 70 bpm and heart rate fluctuations 1 - 4 bpm, the 93.3% （97/104） inmges for the diagnostic requirements were got; Group C： with heart rate 71 - 80 bpm and heart rate fluctuations 1- 4 bpm, the 87.5% （49/56） images for the diagnostic requirements were got; Group D： with heart rate -81 bpm and heart rate fluctuations 2 - 5 bpm, the 33.3% （4/12） images for the diagnostic requirements were got. Conclusion：The methed of using direct breath holding at eupnea with 64-slice CT coronary angiograpby is beneficial to reduce average heart rate and heart rate variability. In this way, we could improve the achievement ratio of examination.