摘要
目的比较64排CT冠状动脉成像的三种管电流曝光技术,探讨其最为合适的管电流控制方式。方法从900例CT冠状动脉成像患者中,回顾性地分析180例CT冠状动脉成像的图像质量,分A、B、C三组,每组60例,使每组病例在年龄、性别、体重、心率四方面无显著性差异（P〉0.05）,A组固定管电流700mA扫描;B组按体重为50~65kg、66~80kg、〉80kg分三小组,分别用330~430mA、430~530mA、530~630mA扫描;C组用ECG调制管电流曝光技术扫描;A、B、C三组其余扫描和重建方式相同：120kV、0.35s/360°、层厚0.625mm、螺距pitch0.20~0.26,按标准算法重建图像。由两名副主任医师以双盲法分别对A、B、C三组图像进行质量评分,比较A、B、C三组各自平均CT剂量指数（CTDI）、累计受照射剂量（DLP）和有效剂量（ED）的差值。结果①A、B、C三组图像质量评分分别为3.77分±0.22、3.74分±0.32、3.75分±0.36,对A、B组间,A、C组间差异进行t检验,P〉0.05,无显著性差异。②A、B、C三组各自平均CTDI、DLP和ED分别为122.84±8.82mGy/slice、2356.80mGy-cm、40.07mSv;92.37±5.92mGy/slice、1772.20mGy-cm、30.13mSv;75.02±4.36mGy/slice、1314.00mGy-cm、22.34mSv。C组指标值低于B组,且C组明显低于A组,组间差异有显著性,P〈0.05结论运用ECG调制管电流曝光技术能获得优质的冠状动脉成像质量,同时能有效地减少曝光量及辐射剂量,减少患者的辐射危害。
Objective To investigate the optimal tube current control strategies on 64-row multidetector computed tomography coronary angiography. Methods One hundred and eighty consecutive patients underwent 64-row multidetector CT coronary angiography （CCTA） for coronary artery disease. They were divided into three groups （each group, n=60） according to different tube current control strategies. Age, weight, generator and mean heart rate were not significantly different among the groups.Group A had undergone CCTA with fixed tube current of 700 mA, group B with 330-430 mA, 43-530 mA and 530-630 mA, respectively, according to weight of 50-65 kg, 66-80 kg and 〉80 kg. However, group C with AutomA exposure control. The scan and reconstruction parameters were as follows： 120 kV, 0.35 s/360°, 0.6 mm section thickness and 0.20-0.26 pitch. The imaging scores were evaluated by two reviewers and the value of noise, CT does index-volume （CTDI）, dose length product （DLP） and effective dose （ED） were calculated among the groups, respectively. Results The mean score of imaging quality in group A, group B and group C was 3.77±0.22, 3.74±0.32 and 3.75±0.36, respectively.No significant difference of the mean score was found between group A and group B, group A and group C, respectively（P〉0.05）. The value of CTDI in group A, group B and group C was 122.84±8.82, 92.37±5.92 and 75.02±4.36 mGy/slice, respectively, DLP was 2356.80, 1772.20 and 1314.00 mGy-cm, respectively, ED was 40.07, 30.13 and 22.34 mSv, respectively. The value of CTDI, DLP and ED in group C were significant lower than those in group A or group B （P〈0.05）. Conclusion The application of ECG-gated AutomA exposure control at 64-row multidetector CT coronary angiography result in significant reduction of effective radiation dose, without significant loss of image quality.
出处
《中国医学影像技术》
CSCD
北大核心
2008年第9期1473-1475,共3页
Chinese Journal of Medical Imaging Technology
