摘要
目的:探讨身体质量指数(BMI)指导下对比剂不同流流率对冠脉CTA图像质量的影响。方法:前瞻性收集160例临床疑似冠心病的患者,分为A、B、C、D组,每组40例。A、B、C组注射剂量采用BMI指导下的对比剂剂量,注射时间分别为9s、10s、11s,计算相应流率;D组注射剂量为BMI指导下对比剂剂量+20ml,流率为C组流率。记录4组患者监测时ROI达到阈值时的监测时间、监测次数、达到阈值时的CT值和有效辐射剂量(ED)。评价图像质量,客观评价指标包括主动脉根部(AO)的信噪比(SNR)和对比噪声比(CNR),以及左冠状动脉主干(LM)、右冠状动脉近段(RCA)的CNR,并对血管节段进行主观评分。结果:4组达到阈值时的监测时间分别为(6.6±1.8)、(7.5±2.2)、(8.2±2.3)和(9.0±2.8)秒,ED分别为(0.120±0.047)、(0.141±0.051)、(0.152±0.064)和(0.179±0.075)m Sv,差异均有统计学意义(P均<0.05)。4组间AO、RCA和LM的SNR和CNR的差异均无统计学意义(P均>0.05);图像质量评分差异无统计学意义(P>0.05)。结论:在BMI指导下行冠状动脉CTA检查,适当改变对比剂的流速对图像质量无明显改变,增大对比剂用量不能提高冠脉CT值;相对注射速度越快,阈值监测时间越短,所受辐射剂量越少。
Objective： To investigate the effects of the quality of coronary CTA images with different flow rate of contrast media under the guidance of body mass index （BMI）.Methods： This prospective study including 120 patients with suspected coronary artery disease （CAD）.The patients were divided into groups A,B,C and D （n = 40 for each group）.The contrast agent used in The patients of groups A,B and C were under the guidance of BMI.The injection time was 9s,10 s,11S,respectively,and the corresponding flow rate was calculated.The dose of group D was the dose of group C ＋ 20 ml.The monitoring time when CT density of the region of interest （ROI） reached the threshold,the CT value and the effective dose （ED） in the 4 groups were recorded.To evaluate the image quality,the objective evaluation included signal noise ratio （SNR） and contrast noise ratio （CNR） of aorta （AO）,CNR of left main coronary artery （LM） and right coronary artery （RCA）,and the subjective score was recorded for each coronary artery segment.Results： The monitoring time of to reach the threshold in groups A,B,C and D were （6.6 ± 1.8） 、 （7.5 ± 2.2） 、 （8.2 ± 2.3） and （9.0 ± 2.8） sec,and ED were （0.120 ± 0.047）,（0.141 ± 0.051）,（0.152 ± 0.064） and （0.179 ± 0.075） m Sv,with the significant difference （P 0.05）.There was no significant difference in AO （SNR and CNR）,LM （CNR）,RCA （CNR） and Subjective image quality scores among the 4 groups,respectively （P 0.05）.Conclusions： When examining coronary artery CTA by BMI guiding,there is no obvious change on image quality with changing the contrast velocity,increasing the amount of contrast agent can＇t improve coronary CT value,the faster the relation injected,threshold monitoring time shorter and the radiation dose less.
出处
《现代医用影像学》
2017年第4期881-886,共6页
Modern Medical Imageology
基金
南方医科大学第五附属医院院长基金
关键词
冠状血管
体层摄影术
X线计算机
触发扫描技术
Coronary vessels
Tomography, X - ray computed
Bolus - tracking trigger scanning technology
