摘要
目的探究在低kVp CT结肠造影(CTC)应用不同权重自适应统计迭代重组算法(ASIR-V)的图像质量和辐射剂量,探寻超低辐射剂量CTC的最佳ASIR-V权重。方法前瞻性搜集行CTC扫描的患者35例[体质量指数(BMI)≤25 kg/m^(2)],所有患者均采用Revolution CT扫描。患者取双体位(仰卧位和俯卧位)扫描,俯卧位扫描管电压120 kVp(A组),应用30%ASIR-V重组图像,仰卧位采用70 kVp,重组30%~90%(间隔10%)ASIR-V图像(B1~B7组)。测量轴位图像中肿物及肠腔空气(背景)均匀处CT值和噪声(SD)值,计算信噪比(SNR)及对比噪声比(CNR),记录患者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)。由两位观察者采用双盲法独立对两组图像质量行5分制评分并行一致性检验。比较A、B组图像主客观质量及辐射剂量。结果A、B组图像CT值均无差异(P>0.05),随着ASIR-V权重的增加,B组30%~90%ASIR-V图像SD降低,SNR和CNR增加(P<0.05),其中60%ASIR-V图像SD、SNR及CNR与A组无差异(P>0.05),70%~90%ASIR-V图像的SD值显著低于A组,SNR和CNR明显高于A组(P<0.05)。两位观察者对所有图像主观评分一致性较好(Kappa值0.712~0.863,P<0.05),所有ASIR-V重组图像均能满足诊断要求,70%ASIR-V图像主观评分最高5.0(5.0,5.0)。B组CTDIvol和ED分别为(1.59±0.14)mGy和(1.15±0.15)mSv,与A组相比,分别降低了62.73%和64.20%(P<0.05)。结论在超低辐射剂量CTC扫描中,应用ASIR-V能够有效改善图像噪声,提高图像对比度,显著降低辐射剂量,其中70%ASIR-V为最佳权重。
Objective To explore the image quality and radiation dose of the application of adaptive statistical iteration algorithm(ASIR-V)in low kVp CT colonography(CTC),the optimal ASIR-V weight of low radiation dose CTC was explored.Methods 35 patients who underwent CTC scans(BMI≤25 kg/m^(2))by Revolution CT.Patients were scanned in a two-body position(supine and prone positions)with a tube voltage of 120 kVp(group A)and a 30%ASIR-V reconstruction image was applied,and 70 kVp was used in the supine position to reconstruct 30%to 90%(10%interval)ASIR-V images(B1 to B7 groups).The mass and the air of the intestinal cavity(background)of CT and SD values were measured at the axial image,the SNR and CNR were calculated,the CTDIvol and DLP were recorded,and the ED was calculated.Two observers independently performed consistency tests on image quality line-5-point scale scores using a double-blind method.The subjective and objective quality of the images and the radiation dose of groups A and B were compared.Results There was no difference in CT values between groups A and B(P>0.05).With the increase of ASIR-V weights,SD of 30%-90%ASIR-V images in group B decreased,while SNR and CNR increased(P<0.05),the SD,SNR and CNR of 60%ASIR-V images were not different from those of group A(P>0.05),the SD values of 70%-90%ASIR-V images were significantly lower than those of group A,and the SNR and CNR of group A were significantly higher than those of group A.(P<0.05).The two observers had good consistency in the subjective scores of all images(Kappa value=0.712-0.863,P<0.05),all ASIR-V reconstructed images could meet the diagnostic requirements,and 70%of ASIR-V images had the highest subjective score of 5.0(5.0,5.0).CTDIvol and ED in group B were(1.59±0.14)mGy and(1.15±0.15)mSv,respectively,which were 62.73%and 64.20%lower than those in group A(P<0.05).Conclusion In ultra-low radiation dose CTC scanning,the application of ASIR-V can effectively improve image noise,improve image contrast,and significantly reduce radiation dose,of which
作者
李贝贝
刘义军
赵明月
王旭
魏巍
刘爱连
LI Beibei;LIU Yijun;ZHAO Mingyue(The First Affiliated Hospital of Dalian Medical University,Dalian,Liaoning Province 116011,P.R.China)
出处
《临床放射学杂志》
北大核心
2023年第2期322-327,共6页
Journal of Clinical Radiology
关键词
低剂量
迭代重组算法
CT结肠造影
辐射剂量
Low dose
Iterative reconstruction algorithm
CT colonography
Radiation dose
