绝对时相收缩期采集降低心房颤动患者冠状动脉CT成像辐射剂量的研究

目的:研究绝对时相收缩期采集在心房颤动患者冠状动脉CT血管造影(CTA)的可行性,并与相对时相采集对照。方法:连续入组92例持续心房颤动患者,其中A组46例采用绝对时相收缩期采集(R波后200~400ms),B组46例采用相对时相收缩期采集(R-R间期:30%~50%)。对两组扫描的冠状动脉分别做图像处理。比较两组的图像质量和辐射剂量。结果:A组冠状动脉段图像质量总体评分为(1.56±0.25),B组为(1.62±0.28),两组间差异无统计学意义(P=0.283)。两组之间可诊断的冠状动脉段比率差异无统计学意义(P=0.785)。A组有效剂量5.76(3.20,8.63)mSv;B组有效剂量9.27(4.74,12.65)mSv,两组间有效剂量差异有统计学意义(P=0.001)。绝对时相采集比相对时相采集降低辐射剂量约38%。结论:在心房颤动患者绝对时相收缩期采集具有可行性,该方案比相对时相采集显著降低辐射剂量,而不影响图像质量。

Absolute phase acquisition versus relative phase acquisition for dual source CT coronary angiography in patients with atrial fibrillation

Objective：To investigate the feasibility of absolute phase systolic acquisition for coronary CT angiography （CCTA） in patients with atrial fibrillation （AF） with comparison to relative phase acquisition.Methods：Ninety-two patients with persistent AF were enrolled in the study,46 patients were scanned with absolute phase systolic acquisition （200-400 ms after the R wave） and another 46 were studied by relative phase systolic acquisition （30％-50％ of the R-R interval） for CCTA using the second generation dual source CT （DS-CT）.The imaging quality and radiation dose were compared between the two protocols.Results：There was no significant difference in overall image quality between the two groups （P =0.283）.Median effective doses of absolute phase acquisition and relative phase acquisition were 5.76 （3.20,8.63） mSv and 9.27 （4.74,12.65） mSv respectively （P =0.001）,showing that absolute phase acquisition reduced radiation dose by 38％ compared with that of relative phase acquisition.Conclusion：In patients with AF,absolute phase systolic acquisition is feasible in DS-CT coronary angiography,and can decrease radiation exposure by approximately 35％ compared with relative phase acquisition,while preserving image quality.