不同心电门控技术在256层螺旋CT冠脉成像中应用的对比研究

Comparative study on the role of prospective ECG-gating and retrospective ECG-gating protocol in 256-slice CT coronary angiography

目的比较前瞻性门控和回顾性门控两种心电门控技术对256层螺旋CT冠脉成像图像质量和辐射剂量的影响。方法回顾分析230例疑诊冠心病患者256层CT冠脉成像的情况。105例使用前瞻性门控扫描。125例使用回顾性门控扫描,其中58例心率控制不佳的患者同时使用两种门控扫描。统计患者的扫描时间和辐射剂量,按CT质量标准统计图像质量评分。结果①前瞻性门控扫描时扫描时间及辐射剂量均明显低于回顾性门控组([3.43±0.19)s vs(5.23±0.37)s,P<0.01;(7.20±0.75)mGy/s v(s10.29±1.31)mGy/s,P<0.01];②同一患者使用两种不同门控扫描时,前瞻性门控的扫描时间及辐射剂量均明显低于回顾性门控组([3.13±0.19)s vs(5.21±0.36)s,P<0.01;(7.19±0.80)mGy/s v(s9.95±2.51)mGy/s,P<0.01];③前门控组冠脉图像的运动伪影及图像质地得分优于后门控([0.91±0.29)vs(0.38±0.49),P<0.01;(1.80±0.40)vs(1.59±0.49),P<0.05],冠脉图像质量总分亦优于回顾性门控组([8.36±0.68)v(s7.27±0.84),P<0.01];④当心率>75次时,同一患者前门控扫描图像的运动伪影得分明显低于后门控扫描,但图像质量总分无明显差别([0.21±0.24)vs(0.48±0.29),P<0.01;(6.41±0.65)v(s6.67±0.82),P>0.05)]。结论相对于回顾性门控,前瞻性门控辐射剂量小,图像质量好,可更多地应用于冠脉成像。但即使使用256层CT,前瞻性门控的冠脉成像质量仍然受到心率的限制。

[ Objective ] To evaluate the effects of prospective ECG-gating （PEG） and retrospective ECG-gating （REG） protocol on the image quality and radiation dose in 256-slice CT coronary angiography （CTA）. [ Methods ] 230 patients with chest jam or pain and suspected diagnosis of coronary heart disease, who were examined with 256 multi-slice spiral CT, were included and reviewed. PEG protocol was utilized in 105 patients and REG protocol in 125 patients. 58 patients were examined with both PEG and techniques due to uncontrolled heart rate. The scanning time, radiation dose and image quality were compared. [ Results ]①The scanning time and radiation dose were sig- nificantly decreased in PEG group compared with that in REG group[（3.43±0.19） s vs （5.23±0.37） s, P 〈0.01; （7.20± 0.75） mGy/s vs （10.29±1.31） mGy/s, P 〈0.01]. ②The similar diversity of scanning time and radiation dose was ob-served in the self-controlled patients [（3.13±0.19） s vs （5.21±0.36） s, P 〈0.01; （7.19±0.80） mGy/s vs （9.95±2.51） mGy/s, P 〈0.01]. ③The Image artifaets, texture and total score of image quality in PEG group overmatched that in REG group[（0.91±0.29） vs （0.38±0.49）, P 〈0.01; （1.80±0.40） vs （1.59±0.49）, P 〈0.05; （8.36±0.68） vs （7.27±0.84）, P 〈0.01]. ④The patients with more than 75 bpm showed lower image artifacts score and similar total score when scanned with PEG protocol versus REG protocol [（0.21±0.24） vs （0.45±0.50）, P 〈0.01; （6.41±0.65） vs （6.67±0.82）, P 〉0.05）. [ Conclusion ] Our results suggest that with lower radiation dose and relatively finer image quality, PEG pro- toeol eould deserve more application in CTA. On the other hand, despite of utilizing 256-sliee CT, PEG protocol is limited to patient cohorts strictly defined by heart rate and applies only to appropriately selected patients.