摘要
目的评价64层CT冠状动脉成像中前瞻性轴面扫描不同kV设置对射线剂量及图像质量的影响及临床应用价值，探讨〈1mSv冠状动脉检查的可行性。方法从拟行冠状动脉成像的患者中连续选取90例体质量指数（BMI）〈21．5kg／m2，且心率满足前瞻性门控轴面扫描条件的患者，平均心率（54±6）次／min（bpm）。90例患者数字表法随机分成A、B2组，A组45例扫描时管电压为100kV，B组45例扫描时管电压为120kV，根据患者BMI选择管电流，记录扫描中患者所受射线剂量，并对其图像质量进行评价（5分优，1分差）。采用配对t检验对2组的射线剂量和图像质量进行统计学分析。结果A组平均扫描剂量为（0．88±0．32）mSv，图像质量评分平均为（4．32±0．28）分；B组平均扫描剂量为（1．47±0．41）mSv，图像质量评分平均为（4．52±0．34）分。A、B组之间图像质量评分差异无统计学意义（t=0．771，P〉0．05）：A组扫描剂量与B组相比较差异有统计学意义（t=12．125，P〈0．0t），平均减少40％。结论64层CT冠状动脉成像前瞻性轴面扫描中，对于BMI〈21．5kg／m2。的患者，可采用100kV管电压扫描，其辐射剂量可降到1mSv以下，并且其图像质量能满足临床诊断需要。
Objective To evaluate radiation dose and image quality of prospective electrocardiograph （ECG）-triggered coronary 64-slice CT angiography （CTA） with different kV, and the feasibility of coronary scan with 〈 1 mSv radiation dose. Methods Ninety consecutive patients[ heart rate： （54 ±6） bpm, BMI 〈 21.5 kg/m2 ] underwent 64-slice CTA using prospective ECG-triggered axial scan protocol. They were divided into two groups： 45 were in group A（ 100 kV） , 45 were in group B（ 120 kV） , and their electric currents were tailored to patient＇s BMI. The radiation dose was recorded and the image quality（5 fur excellent, 1 for bad）was blindly evaluated. Statistical t-test was performed between two groups on dose and image quality. Results The radiation dose of group A, B was （ 0. 88 ±0. 32 ） , （ 1.47 ±0. 41 ） mSv respectively. There was no significant difference between image quality of group A with 100 kV （4. 32±0. 28） and that of group B with 120 kV （4. 52 ±0. 34） （t =0. 771 ,P 〉0. 05）. And radiation dose of the patient using axial scan protocol at 100 kV was decreased by 40% compared with that of group B at 120 kV（t = 12. 125, P 〈 0. 01 ）. Conclusion Prospective ECG-triggered axial scan in 64-slice coronary CTA can significantly reduce radiation exposure. For low-BMl （ 〈 21.5 kg/m2 ） patients, super low dose scan （ 〈 1 mSv） at 100 kV using prospective ECG-triggered axial scan could be selected. And the image quality can meet clinical diagnostic needs.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2009年第12期1255-1259,共5页
Chinese Journal of Radiology
