朱红伟　王素娟　王晔　马士华

低辐射剂量在超重和肥胖人群冠状动脉CTA中的应用研究

朱红伟王素娟王晔马士华

【摘要】目的初步探讨通过降低kV降低超重和肥胖人群冠状动脉CTA辐射剂量的可行性。方法连续收集超重患者60例、肥胖患者72例，每组均分成低剂量组和常规剂量组，分别记作A1和A2、B1和B2组，A1组采用100 kV、A2和B1组120 kV、B2组采用140 kV，对比剂选用碘海醇(350mg/ml)进行增扫描。对冠状动脉9个主要节段图像进行主观评分，对右冠状动脉近段(RCA-p)、左主干LM(LMA)、左前降支近段(LAD-p)、左回旋支近段(LCX-p)4个主要节段管腔增强后CT值及SD和同水平前胸壁肌肉组织的CT值及SD进行记录。对A1和A2、B1和B2以上增强水平、图像评分、图像噪声、信噪比(SNR)、噪声比(CNR)、有效辐射剂量(ED)等进行分析比较。结果所有纳入病例均完成冠脉检查，图像质量满足诊断要求。9个冠脉节段图像评分、4个冠脉节段增强水平、图像噪声、SNR差异无明显统计学意义，CNR、ED差异具有统计学意义。A1组和A2组ED分别为(8.47±0.76)mSv和(12.22±2.41)mSv，B1和B2组ED分别为(13.69±1.142)mSv和(20.31±1.36)mSv。结论对于超重和肥胖人群进行冠脉检查，可通过降低kV减少检查个体的有效辐射剂量，降低冠脉图像CNR。

【关键词】对比剂;超重;肥胖;体重指数;体层摄影术，X线计算机;辐射剂量

【中图分类号】R 445.3

【文献标识码】A

【文章编号】1002－7386(2015)16－2418－04

doi:10.3969/j.issn.1002－7386.2015.16.005

【Abstract】Objective To investigate the feasibility of reducing coronary CTA radiation dose through decreasing kV in overweight and obesity patients.Methods Sixty overweight patients and 72 obesity patients were selected consecutively.These patients were divided into low-dose group and conventional-dose group，which were denoted as group A1，group A2，group B1 and group B2，respectively.100kV for group A1，120kV for group A2 and group B1，140kV for group B2.The contrast agent(iohexol，350mg/ml)was used for enhancement scanning.The image quality of the ninemajor segments of coronary artery were evaluated by subjective scoring.The enhanced CT values of the four segments including proximal right coronary artery(RCA-p)，leftmain artery(LMA)，proximal left anterior descending artery(LAD-p)，proximal left circumflex artery(LCX-p)andmuscle tissue of chest wall at the same levels were recorded.The enhancement levels above A1，A2，B1，B2，image quality score，image noise，signal to noise ratio(SNR)，contrast to noise ratio(CNR)，effective radiation dose(ED)were analyzed and compared bymeans of two independent samples t-test.Results All the patients completed coronary artery examination，and the image qualitymet the diagnostic requirement.There were no significant differences in image score of 9 coronary segments，enhancement levels，image noise and SNR of the four coronary segments，however，there were significant differences between CNR and ED.The ED in group A1 and A2 were(8.47±0.76)mSv and(12.22±2.41)mSv，respectively，which in group B1 and B2 were(13.69±1.142)mSv and(20.31±1.36)mSv，respectively.Conclusion The coronary artery examination for overweight and obesity patients can reduce kV to decrease effective radiation dosage and decrease coronary image CNR.

收稿日期:(2015－02－13)

作者单位: 071051河北省保定市第二医院(朱红伟、王素娟、王晔);河北省保定市第一医院CT/MRI室(马士华)

Application of low radiation dosage of coronary CTA in overweight and obese patients

ZHU Hongwei，WANG Sujuan，WANG Ye，et al.CT Department，The Second Hospital of Baoding City，Hebei，Baoding 071000，China

【Key words】contrastmedia; overweight，obesity; BMI; tomography，X-ray computed; radiation dosage

进行放射线检查个体的辐射剂量是近几年研究的热点。自从1895年发现放射线以来，它给人类带来的丰富影像信息的同时，也对我们的身体健康造成了损害［1，2］，所以影像工作者总是在求证各种减少辐射剂量［3－6］的方法，力求每种方法即能满足诊断需要又符合辐射剂量合理化和最优化原则。……