CT模拟定位机扫描条件对图像质量的影响  

The influence of scanning condition of CT simulated positioner on image quality

作　　者：张坤 韩晶晶 李芳[2] 王学敏 邓佳 杨迪 吴湘阳 ZHANG Kun;HAN Jingjing;LI Fang;WANG Xuemin;DENG Jia;YANG Di;WU Xiangyang(Department of Radiation Oncology,Shaanxi Province Cancer Hospital,Shaanxi Xi'an 710061,China;The Second Affiliated Hospital of Xi'an Jiaotong University,Shaanxi Xi'an 710004,China)

机构地区：[1]陕西省肿瘤医院放疗科,陕西西安710061 [2]西安交通大学第二附属医院,陕西西安710004

出　　处：《现代肿瘤医学》2022年第4期693-697,共5页Journal of Modern Oncology

基　　金：陕西省卫建委项目(编号:2018A007)。

摘　　要：目的:分析大孔径CT模拟定位机不同扫描条件对CT图像的影响,为模拟定位工作中扫描协议的选择提供参考。方法:利用飞利浦大孔径CT模拟定位机扫描Catphan504模体,分析管电压、管电流、层厚、过滤器、扫描方式、扫描视野、摆放位置等扫描条件对CT图像的影响。结果:CT值参数受管电压及过滤器影响明显,140 kV管电压CT值最大偏差为69.6 HU;Sharp Edge过滤器最大偏差为215.3 HU。图像均匀性受过滤器Detail、Y-Sharp、Y-Detail影响明显。空间分辨率参数受矩阵、过滤器、摆放位置参数影响明显。对比度分辨率参数受管电流及过滤器影响明显。结论:管电压、管电流、过滤器、矩阵、摆放位置对CT图像的影响不可忽略,临床工作中可根据实际需要选择合适的扫描条件,在保证CT值准确的同时提高图像质量。Objective:To analyze the influence of different scanning conditions of large-size CT simulation positioning machine on images quality,and provide reference for the selection of scanning protocol in simulation positioning work.Methods:The Catphan504 phantom was scanned with a Philips large-aperture CT simulation positioning machine,and the influence of scanning conditions such as tube voltage,tube current,layer thickness,filter,scanning method,scanning field of view,and placement position on the CT image was analyzed.Results:The CT grayscale value was obviously affected by the tube voltage and the filter.The deviation of CT grayscale value is 69.6 HU for the 140 kV tube voltage.The maximum deviation of CT grayscale value was 215.3 HU for the Sharp Edge filter.The image uniformity was obviously affected by the filters Detail,Y-Sharp,and Y-Detail.The spatial resolution parameters were significantly affected by the matrix,filter,and placement parameters.The contrast resolution parameter was obviously affected by the tube current and the filter.Conclusion:The influence of tube voltage,tube current,filter,matrix,and placement position on CT images cannot be ignored.In clinical work,appropriate scanning conditions should be selected according to clinical requirements to improve the image quality while ensuring the accuracy of CT values.

关 键 词：放射治疗 CT模拟定位机 扫描协议 图像质量 

分 类 号：R730.55[医药卫生—肿瘤]