柱状金属模体CT伪影的相关分析与研究  

Correlation analysis and research of CT artifacts of columnar metal phantom

作　　者：李巍伟[1] 连涛[1] 翟继良[1] Li Weiwei;Lian Tao;Zhai Jiliang(Department of Radiology,Tai＇an Central Hospital Branch,Tai＇an 271000,China)

机构地区：[1]泰安市中心医院分院放射科,山东省271000

出　　处：《中华消化病与影像杂志（电子版）》2018年第3期112-115,共4页Chinese Journal of Digestion and Medical Imageology(Electronic Edition)

摘　　要：目的通过对不同直径柱状金属模体扫描并与空扫图像对比,研究金属模体伪影对周围像素CT值影响。方法相同条件扫描不同直径柱状金属模体,并与空扫图像作对照,确定研究像素的范围,以单一像素测量单位,测量两种模体图像对应研究区域的像素CT值并与空扫形成像素CT值数据做对照,研究分析CT值变化特点。结果通过不同直径金属模体扫描并与空扫对比,柱状金属模体对周围像素的CT值均产生确切影响,导致周围像素CT值较空扫均不同程度增加,不同直径模体间对像素CT值影响程度存在差异。射束硬化在柱状金属周缘形成环状伪影,其像素CT值显著区别于邻近像素CT值的变化。结论金属模体对其周围像素CT值影响与模体直径正相关,与像素和模体距离负相关,射束硬化现象使金属模体周缘像素CT值远低于邻近像素。Objective To investigate the effects of metal artifact artifacts on the CT values of surrounding pixels are investigated by scanning different diameter columnarcylindrical metal modules and comparing them with empty scanning images. Methods The same scanning of different diameter columnar metal modules were scanned in the same condition,and compared with empty scanning images. The range of pixel was mould body,and empty scan images were determined. on the range of pixels,a single pixel CT pixel unit of measurement,measurement of The pixel CT values of two kinds of phantom images corresponding to the study area were measured by single pixel measurement unit,and compared with value and air scan form pixelthe CT values of empty scanning images data control,analysis t. The changing characteristicses of CT values were analyzed. Results Through the comparison of different diameter metal module scanning and emptyair scanning,the columnarcylindrical metal mold has had a definite influence on the CT value of the surrounding pixels,resulting in the increase of the CT value of the surrounding pixels to different degrees comapred with empty scanning,and t. The influence degree of pixel CT value between different diameter modules wais different. The ring artifact was formed by beam hardening is formed by a circular artifact atin the columnar metal peripheryrim,and its pixel CT value wais significantly different from the change in the CT value of the adjacent pixels. Conclusion The influence of the metal module on the CT value of the surrounding pixel is positively related to the moduledie diameter,and is negatively related to the pixel and module distance. The beam hardening causes the CT value of the peripheral pixel of the metal module to be much lower than that of the neighboring pixel.

关 键 词：金属伪影 射束硬化伪影 CT值 

分 类 号：R814[医药卫生—影像医学与核医学]