不同管电压64层螺旋CT对儿童CTA图像质量和辐射剂量的影响  

Impact of different tube voltage protocols on image quality and radiation dosage for pediatric 64-slice cardiovascular CT angiography

作　　者：张健[1] 杨明[1] 莫绪明[2] 靳激扬[1] 刘斌[1] 黎玲玲[1] 滕皋军[1] 

机构地区：[1]东南大学附属中大医院放射科,江苏南京210009 [2]南京医科大学附属南京儿童医院心胸外科,江苏南京210008

出　　处：《中国医学影像技术》2012年第6期1213-1217,共5页Chinese Journal of Medical Imaging Technology

摘　　要：目的用64层螺旋CT观察不同管电压(80kVp及100kVp)对儿童CTA图像质量(IQ)和辐射剂量(ED)的影响。方法回顾性分析52例先天性心脏病患儿心脏CTA检查资料,根据扫描管电压分为80kVp组(n=30)及100kVp组(n=22),均采用自动管电流调制技术。采用bolus tracking技术自动注射对比剂,记录增强后心腔和大血管的密度,测量背景噪声,计算SNR、对比噪声比(CNR)及有效剂量(ED)。由2名医师采用单盲法评估图像质量。结果 80kVp和100kVp两组心腔大血管平均密度、SNR及CNR差异均无统计学意义(P均>0.05);IQ评分分别为4.17±0.70、4.23±0.53(P=0.834);80kVp组平均ED为(0.458±0.085)mSv,低于100kVp组的(1.074±0.290)mSv(P<0.001)。结论儿童心脏CTA检查中,与100kVp相比,80kVp管电压可明显降低ED而不影响IQ。Objective To evaluate the impact of 80 and 100 kVp tube voltage on image quality（IQ） and radiation dosage in pediatric cardiovascular CT angiography（CTA） with 64-slice CT.Methods CTA was performed in 52 children with suspected congenital heart disease.Children were randomly assigned to 80 kVp（n=30） or 100 kVp（n=22） group.Other scanning parameters were kept constant.Contrast medium was injected automatically with bolus tracking.Enhancement of heart chamber and great vessels and SNR,contrast-to-noise ratio（CNR） and effective dose（ED） were calculated.Subjective vessel contrast was assessed by two radiologists in consensus.Results There was no statistical difference of mean vessel attenuation,SNR and CNR between the two groups（all P0.05）,nor of subjective IQ（4.17±0.70 vs 4.23±0.53,P=0.834）.Mean ED for 80 kVp group（[0.458±0.085]mSv） was significantly lower than that for 100 kVp group（[1.074±0.290]mSv,P0.001）.Conclusion Reduction of tube voltage from 100 to 80 kVp can result in significant decrease of ED in pediatric cardiovascular CTA without deteriorating image quality.

关 键 词：儿童 心脏缺损 先天性 体层摄影术 X线计算机 血管造影术 图像质量 辐射剂量 

分 类 号：R814.42[医药卫生—影像医学与核医学] R541.1[医药卫生—放射医学]