CT扫描参数及重建算法对胸部CT值影响的在体研究  

In Vivo Study of the Influence of CT Acquisition and Reconstruction Parameters on Chest CT Number

作　　者：李晶晶 张丽 刘梦雯 杨守鑫 李蒙 姜九明 于卫军 LI Jingjing;ZHANG Li;LIU Mengwen;YANG Shouxin;LI Meng;JIANG Jiuming;YU Weijun(Departments of Radiology,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100021,China;Department of Radiology,Peking University Cancer Hospital&Institute,Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education),Beijing 100142,China)

机构地区：[1]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院影像诊断科,北京100021 [2]北京大学肿瘤医院暨北京市肿瘤防治研究所医学影像科/恶性肿瘤发病机制及转化研究教育部重点实验室,北京100142

出　　处：《CT理论与应用研究（中英文）》2023年第4期480-486,共7页Computerized Tomography Theory and Applications

基　　金：北京市自然科学基金(以像元灰度为基础的影像学特征在早期肺腺癌预后判断中的研究(7184238));国家自然科学基金(基于基线CT放射组学的肺亚实性结节生长模式预测及分子病理基础研究(81701692))。

摘　　要：目的:探讨不同扫描参数及重建算法对在体胸部各组织CT值的影响。方法:在不同CT扫描条件下测量人体胸部的气管、血管、肺、椎体与肌肉的CT值。分别设定6组不同扫描参数及重建算法:S1层厚5 mm、50%多模型自适应迭代重建技术(ASIR-V)、低剂量;S2层厚5 mm、滤波反投影(FBP)、常规剂量;S3层厚1.25 mm、50%ASIR-V、低剂量;S4层厚1.25 mm、50%ASIR-V、常规剂量;S5层厚1.25 mm、FBP、低剂量;S6层厚1.25 mm、FBP、常规剂量。扫描的辐射剂量采用两种噪声指数(NI)来进行控制,包括低剂量(NI=40)和常规剂量(NI=10)。采用t检验或秩和检验分析比较不同的两个组之间CT值的差异。结果:扫描剂量仅对气管CT值的影响具有统计学意义,对其他组织CT值无影响;扫描层厚与重建算法对胸部各个组织CT值的影响均未见统计学差异。结论:人体胸部组织CT值受CT层厚、重建算法和CT剂量的影响小,具有良好的稳定性。Objective:To explore the influence of different CT acquisition and reconstruction parameters on the CT number of the chest in vivo.Methods:The CT number of the trachea,blood vessels,lungs,vertebral bodies,and muscles of the human chest were measured under different CT scanning parameters.Six groups of different scanning parameters and reconstruction algorithms were set respectively:slice thickness 5 mm,50%multi-model adaptive statistical iterative reconstruction Veo(ASIR-V)and low-dose for S1;slice thickness 5 mm,filtered back projection(FBP)and standard-dose for S2;slice thickness 1.25 mm,50%ASIR-V and low-dose for S3;slice thickness 1.25 mm,50%ASIR-V and standard-dose for S4;slice thickness 1.25 mm,FBP,low-dose for S5;slice thickness 1.25 mm,FBP,standard-dose for S6.The radiation dose of the scan was controlled using two noise indexes(NI),including low-dose(NI=40)and standard-dose(NI=10).Differences in CT number between two groups were compared using t-test or rank-sum test.Results:Significant differences of CT number of the trachea were detected between low-dose and standard-dose,but no significant differences of CT number of other tissues were detected between low-dose and standard-dose.No significant differences of CT number of chest tissues were detected between either 5 mm thickness and 1.25 mm thickness or 50%ASIR-V and FBP.Conclusion:The CT number of human chest tissues showed well stability which was scarcely influenced by slices thickness,reconstruction algorithm and scan dose.

关 键 词：CT扫描参数 重建算法 CT值 扫描剂量 

分 类 号：O242[理学—计算数学] TP391[理学—数学]