摘要
目的探讨在超重患者双源CT冠状动脉成像中低管电压技术的应用价值，评价其图像质量和辐射剂量．方法将66例接受双源CT冠状动脉检查，体质量〈85kg、且体质量指数（BMI）为25．0～30．0kg／m^2的患者完全随机化分为A、B2组。A组30例，管电压为120kVp；B组36例，管电压为100kVp。所有患者均采用回顾性心电门控螺旋扫描和四维智能在线剂量调控（CARE Dose 4D）技术，严格控制扫描范围。对2组的扫描数据分别进行多种图像后处理，由影像科副主任医师和副主任技师各1名采用双盲法评估图像质量．测量并计算信噪比（SNR）、对比信噪比（CNR）．记录CT容积剂量指数（CTDIvol）和剂量长度乘积（DLP），计算有效辐射剂量（ED）。应用两独立样本t检验比较2组患者图像ROI的CT值、噪声、SNR、CNR、辐射剂量及对比剂用量、图像质量评分等。应用Х^2检验比较两组患者冠状动脉图像质量分级显示段数。应用Kappa检验判断2名评价者评分的一致性。以P〈0．05为差异有统计学意义。结果图像ROI内CT值、噪声（以标准差SD计算）、SNR测量值：A组右冠状动脉（RCA）起始部分别为（429．3±77．4）HU、24．0±8．2、21．8±9．9，左冠状动脉主干（LMA）起始部分别为（436．7±79．0）HU、19．4±7．3、22．3±9．8；B组RCA分别为（503．5±95．4）HU、34．0±12．6、21．0±10．7，LMA分别为（491．7±96．2）HU、33．4±15．5、20．6±11．4；CNR测量值：A组为24．4±10．3，B组为21．9±8．2。2组患者冠状动脉向管腔内强化平均CT值、噪声比较，B组大于A组，差异有统计学意义（P值均〈0．05）；2组间SNR、CNR差异无统计学意义（P值均〉0．05）；2组CTDIvol比较，A组为（42．2±13．8）mGy，B组为（20．2±6．5）mGy，差异有统计学意义（P〈0．05）；A组ED为（9．5±3．6）mSv，B组为（4．8±1．7）mSv，差异有统计学意�
Objective To investigate the image quality and the radiation dose of dual-source computed tomography coronary angiography by using low kilovoltage combination with low tube current in overweight patients. Methods Sixty-six patients with body mass index （BMI） 25.0 30. 0 kg/m^2 and a body weight 〈 85 kg were randomized two groups （group A and group B）. Thirty patients in group A were examined with 120 kVp, and 36 patients in group B with 100 kVp. ECG-pulsing and care dose 4D for radiation duse reduction were used in all patients. All inmges were transterred to Siemens workstation for post processing and analysis. Two observers blinded to elinieal data independently assessed the image quality of each coronary segment by using a 5-point scoring scale （5： excellent, 1 ： no diagnostic） , and measured the different image parameters including image noise, signal-to-noise ratio （SNR） and contrast-to-noise ratio （CNR）. The effective dose （ED） was calculated by using CT dose volume index （CTDIvol） and the doselength product （DLP）. The mean intraluminal attenuation, image noise, SNR, CNR, radiation dose, volume of contrast medium, and mean image quality scores were compared between the two groups with t test. The grading quantity of coronary artery segment was compared with Chi-square test. The interobserver agreement was determined by Kappa statistics. Results The mean intraluminal attenuation, image noise, SNR in group A were （429.3 ±77.4） HU, 24.0 ±8.2, 21.8 ±9.9 in right coronary artery （RCA） , and （436.7 ±79.0） HU, 19.4 ±7.3, 22. 3 ±9.8 in left main coronary artery （LMA）, and that in group B were （503.5±95.4） HU, 34.0±12.6, 21.0±10.7 in RCA, and （491.7 ±96.2） HU, 33.4±15.5, 20. 6 ±11.4 in LMA. The CNR were 24. 4 ±10. 3 in group A and 21.9 ±8.2 in group B. The mean intraluminal attenuation and image noise were significantly higher for group B compared with group A （ P 〈 0. 05 ）. There were no difference in SNR and CNR between the two groups
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2011年第5期486-491,共6页
Chinese Journal of Radiology
关键词
冠状血管
体重
体层摄影术
螺旋计算机
辐射剂量
Coronary vessels
Body weight
Tomography,spiral computed
Radiation dosage
