多层螺旋CT图像常见伪影的影响因素与解决方案

摘要

目的:探讨多层螺旋CT成像过程中常见伪影的影响因素与解决方案,提高图像质量,获取优质的CT影像.方法:选取139例患者64层螺旋CT扫描后的影像资料,其中头部伪影38例、胸部伪影53例、腹部伪影29例以及盆腔伪影19例,对CT图像伪影的形态和成因逐一进行分析.结果:头部伪影包括:射线束硬化伪影24例、探测器故障伪影1例、斑马样伪影2例、运动伪影1例、金属伪影10例;胸部伪影包括:射线束硬化伪影8例、部分容积效应伪影9例、光子不足伪影9例、欠采样伪影1例、散射伪影3例、运动伪影21例、金属伪影1例、投影数据不完全伪影1例;腹部伪影包括:部分容积效应伪影10例、散射伪影5例、运动伪影4例、金属伪影10例;盆腔伪影包括:光子不足伪影5例、金属伪影14例.分析产生伪影的原因,主要为设备固有因素与检查技术因素两类;提出相应解决方案.结论:多层螺旋CT图像的伪影与设备固有及成像检查技术的诸多因素有关,优化扫描技术参数,可有效消除、抑制或避免图像伪影,获得优质图像.%Objective:To discuss the influence factors and solution of common artifact in the imaging process of multi-slice computed tomography (MSCT), so as to improve the image quality and obtain better quality for image document.Methods: 139 patients once were scanned by using PHILIPS 64-MSCT were enrolled and their documents were analyzed, and these cases included 38 cases with head artifact, 53 cases with chest artifact, 29 cases with abdominal artifact and 19 cases with pelvic artifact. To analyze the morphology and cause of every CT image artifact.Results:In 38 cases with head artifact, 24 cases were caused by hardening of bundle of rays, 1 case was caused by fault of detector, 2 cases were caused by interpolating algorithm, 1 case was caused by motion, 10 cases were caused by metal material. In 53 cases with chest artifact, 8 cases were caused by hardening of bundle of rays, 9 cases were caused by partial volume effect, 9 cases were caused by insufficient photon, 1 case was caused by under-sampling, 3 cases were caused by scattering, 21 cases was caused by motion, 1 case was caused by metal material, and 1 case was caused by data incomplete of projection. In 29 cases with abdomen artifact, 10 cases were caused by partial volume effect, 5 cases were caused by scattering, 4 cases was caused by motion, and 10 cases were caused by metal material. In 19 cases with pelvic artifact, 5 cases were caused by insufficient photon, and 14 cases was caused by metal material.Conclusion: The artifact of MSCT image are related to many factors, the optimizing scan parameters can effectively eliminate, suppress or avoid image artifact, and obtain high quality image.