滤波反投影法与自适应迭代法关于双低儿童胸部CT增强体模的图像质量评估  

Comparison Between Filtered Back Projection Versus Adaptive Iterative Dose Reduction in Pediatric Phantom Chest CT Using Low-Concentration Iodinated Contrast Agent and Low Tube Voltage and Current

作　　者：胡立伟[1] 朱亚新 刘阿利 杜隽[1] 曹少平[2] 钟玉敏[1] HU Liwei;ZHU Yaxin;LIU Ali;DU Jun;CAO Shaopin;ZHONG Yumin(Department of Radiology,Shanghai Jiao Tong University School of Medicine,Shanghai 200127,China;Department of Medical Equipment,Shanghai Children’s Medical Center,Shanghai Jiao Tong University School of Medicine,Shanghai 200127,China;Department of Clinic Research,Canon Medical Systems,Beijing 100015,China)

机构地区：[1]上海交通大学医学院附属上海儿童医学中心放射科,上海200127 [2]上海交通大学医学院附属上海儿童医学中心设备科,上海200127 [3]佳能医疗系统临床研究部,北京100015

出　　处：《中国医疗设备》2020年第4期52-54,64,共4页China Medical Devices

基　　金：十三五科技部重大专项“增材制造与激光制造”子课题(2018YFB1107105);上海市科学技术委员会重点项目(17DZ1930505)。

摘　　要：目的使用儿童胸部模型评估滤波反投影(Filtered Back Projection,FBP)算法与AIDR 3D算法对噪声降低和优化图像质量的差异。方法一个仿真1岁儿童胸部模型的胸腔内配备了6组含有不同碘浓度的管状塑料管,浓度范围0.89~5.29 mgI/mL。该模型在320排CT扫描仪选用低管电压(80 kV)和低电流(13、16、19、22、24、27 mAs)下扫描。图像重建采用FBP、自适应迭代AIDR 3D和AIDR 3D Strong三种方法。测量不同碘浓度的塑料管内和模型组织部分的CT值、图像噪声、对比噪声比(Contrast to Noise Ratio,CNR)。两位放射科医生对影像质量进行独立评估。结果相对于FBP法,AIDR 3D在相同剂量水平下有效降低图像噪声。采用AIDR 3D Strong算法对80 kV和13、16、19、22 mAs儿童胸部模型图像进行了高质量评分(AIDR 3D Strong:3.85±0.39,AIDR 3D:3.54±0.46,FBP:3.17±0.68)。与相同的低剂量方案相比,使用AIDR 3D Strong重建试管(4.42 mgI/mL)的CNR值高于FBP重建试管(5.29 mgI/mL)。结论相比FBP,AIDR 3D Strong显著降低了图像噪声,提高图像质量。对于儿童CT扫描在低辐射剂量下,有进一步降低造影剂的浓度的可能。儿科胸部模型验证可尝试多种低浓度碘化造影剂和低剂量扫描,优化CT扫描方案。Objective To evaluate the impact of the AIDR 3D algorithm on noise reduction and the image quality compared to that of the filtered back projection(FBP)algorithm using a pediatric chest phantom.Methods The cardiac chamber of an anthropomorphic chest phantom was equipped with 6 tubular inserts containing different iodine concentrations,ranging from 0.89 to 5.29 mgI/mL.The phantom was performed on a 320-detector-row CT scanner at low tube voltage(80 kV)and current(13,16,19,22,24,27 mAs).Images were reconstructed with the following algorithms:FBP,adaptive iterative dose reduction 3D(AIDR 3D)and AIDR 3D Strong.The CT attenuation values,image noise,contrast to noise ratios(CNR)of the tubular with different iodine concentrations and muscle part of the phantom were measured.The image quality was assessed independently by two radiologists using a 4-point scale.Results AIDR 3D Strong improved ability to reduce image noise of compared with both FBP and AIDR 3D at same dose levels.The pediatric chest phantom images had highly image quality score in 80 kV and 13,16,19,22 mAs using AIDR 3D Strong algorithm(AIDR 3D Strong:3.85±0.39;AIDR 3D:3.54±0.46;FBP:3.17±0.68).Compared with the same low dose protocol,the use of low-concentration iodinated contrast agent(4.42 mgI/mL)was higher than the CNR of iodinated contrast agent(5.29 mgI/mL)while compared with FBP and AIDR 3D Strong.Conclusion AIDR 3D Strong significantly reduces the image noise compared with FBP and enhances the SNR and CNR with improved image quality.Under the low radiation dose,it has potential to reduce the concentration of contrast agent.

关 键 词：滤波反投影 迭代重建技术 3D打印技术 CT 胸部体膜 儿童 

分 类 号：R144[医药卫生—公共卫生与预防医学] R318