CAJ | 학술논문

目的：探讨使用更窄的曝光时间窗对双源CT冠状动脉成像图像质量和辐射剂量的影响。方法：选择心律稳定、配合屏气在本院行冠状动脉CTA检查者共360例，按心率及扫描方案随机分为5组：当心率＜65次/分时，行回顾性心电门控扫描，用70％～80％曝光时间窗成像冠状动脉（A组）；窄窗方案根据前瞻性心电门控平扫所获得的最佳时相，选择此时相为中心总长1％作为曝光时间窗，行前瞻心电性门控冠状动脉成像（B组）。当心率≥65次/时，行回顾性心电门控扫描，常规使用30％～80％曝光时间窗成像冠状动脉（C组）；窄窗方案根据前瞻性心电门控平扫所获得的最佳时相，以此时相为中心选择总长10％的曝光时间窗，分别用前瞻性心电门控（D 组）和低剂量回顾性心电门控行冠状动脉成像（E组）；分别计算各组平均有效辐射剂量以及冠状动脉图像质量（4分制评分），并作统计学分析。结果：A 组[（8．11±1．54）mSv]和B组[（3．63±0．82）mSv]，C 组[（10．56±2．51）mSv]和 D 组[（4．42±1．16）mSv]，D 组[（4．42±1．16）mSv]和E组[（5．43±1．14）mSv]的辐射剂量相比较均有统计学差异（P＜0．05），采用窄窗方案前瞻性心电门控技术的辐射剂量最少；而各组间图像质量，均无统计学差异（P＞0．05）。结论：前瞻性心电门控通过平扫获得最佳时相，当心率＜65次/分时，选择曝光总长1％的时间窗，而当心率≥65次/分时，选择曝光总长10％的时间窗，能获得高质量的、满足诊断要求的图像，并可有效地降低辐射量。
목적：탐토사용경착적폭광시간창대쌍원CT관상동맥성상도상질량화복사제량적영향。방법：선택심률은정、배합병기재본원행관상동맥CTA검사자공360례，안심솔급소묘방안수궤분위5조：당심솔＜65차/분시，행회고성심전문공소묘，용70％～80％폭광시간창성상관상동맥（A조）；착창방안근거전첨성심전문공평소소획득적최가시상，선택차시상위중심총장1％작위폭광시간창，행전첨심전성문공관상동맥성상（B조）。당심솔≥65차/시，행회고성심전문공소묘，상규사용30％～80％폭광시간창성상관상동맥（C조）；착창방안근거전첨성심전문공평소소획득적최가시상，이차시상위중심선택총장10％적폭광시간창，분별용전첨성심전문공（D 조）화저제량회고성심전문공행관상동맥성상（E조）；분별계산각조평균유효복사제량이급관상동맥도상질량（4분제평분），병작통계학분석。결과：A 조[（8．11±1．54）mSv]화B조[（3．63±0．82）mSv]，C 조[（10．56±2．51）mSv]화 D 조[（4．42±1．16）mSv]，D 조[（4．42±1．16）mSv]화E조[（5．43±1．14）mSv]적복사제량상비교균유통계학차이（P＜0．05），채용착창방안전첨성심전문공기술적복사제량최소；이각조간도상질량，균무통계학차이（P＞0．05）。결론：전첨성심전문공통과평소획득최가시상，당심솔＜65차/분시，선택폭광총장1％적시간창，이당심솔≥65차/분시，선택폭광총장10％적시간창，능획득고질량적、만족진단요구적도상，병가유효지강저복사량。
Objective:To evaluate the image quality and radiation dose of dual-source CT coronary angiography (CT-CA)with a more narrow exposure window.Methods:In all,360 cases underwent dual-source CTCA and were randomly di-vided into five groups according to the heart rate and scanning protocol.Group A,retrospective ECG-gated scan of the pa-tients with heart rate <65 beats per minute (bpm)was performed from 70% to 80%of the R-R interval to reconstruct cor-onary artery;Group B,prospective ECG-gated scan of the patients with heart rate <65bpm was performed with 1% of the total length of the exposure window;Group C,retrospective ECG-gated scan of the patients with heart rate ≥65bpm was performed from 30% to 80% of the R-R interval to reconstruct coronary artery;Group D,prospective ECG-gated scan of the patients with heart rate ≥65bpm was performed with 10% exposure window;Group E,low dose retrospective ECG-ga-ted scan of the patients with heart rate ≥65bpm was performed.The average effective radiation dose and image quality of coronary arteries (4-point scale)were calculated for each group,and statistical analysis was done.Results:Difference of radi-ation dose between each group was statistically significant (P<0.05).A narrowed scan window on prospective ECG gated dual-source CTCA could reduce the radiation dose;while there was no significant difference in the image quality between the groups (P>0.05).Conclusion:Prospective ECG-gated dual-source CTCA can reduce the radiation dose while maintaining good image quality by selecting 1% of the total length of the exposure window(heart rate <65bpm),and 10% of the total length of the exposure window (heart rate ≥65bpm)after obtaining the optimal interval by plain scan.