Thoracic low-dose CT image processing using an artifact suppressed large-scale nonlocal means
Thoracic low-dose CT image processing using an artifact suppressed large-scale nonlocal means
复制标题
使用伪影抑制大规模非局部方法进行胸部低剂量 CT 图像处理
DOI：
10.1088/0031-9155/57/9/2667
复制
发表时间：
2012-05-07
影响因子：
3.5
通讯作者：
Toumoulin, Christine
中科院分区：
文献类型：
--
作者：
Chen, Yang;Yang, Zhou;Toumoulin, Christine
X射线对患者的暴露已成为计算机断层扫描（CT）的主要关注点，并最大程度地减少辐射暴露一直是CT领域的主要努力之一。由于在人体胸部有足够的高衰减组织，在低剂量扫描方案下，胸腔低剂量CT（LDCT）图像往往会因过度斑驳的噪声和非平稳性伪像而严重降解。他们的去除是一项具有挑战性的任务，因为具有方向突出的条纹伪像通常很难与正常组织的衰减信息区分开。本文介绍了一种两步处理方案，称为“伪影抑制了大规模非局部手段”，用于抑制胸腔LDCT图像中的噪声和伪影。利用特定的比例和方向特性来区分噪声和伪影与图像结构。已经引入了并行实现，以加快整个处理超过100次。幻影和患者CT图像都是为了评估目的。进行了比较定性和定量分析，都可以就我们方法改善胸腔LDCT数据的疗效结论。
The x-ray exposure to patients has become a major concern in computed tomography (CT) and minimizing the radiation exposure has been one of the major efforts in the CT field. Due to plenty high-attenuation tissues in the human chest, under low-dose scan protocols, thoracic low-dose CT (LDCT) images tend to be severely degraded by excessive mottled noise and non-stationary streak artifacts. Their removal is rather a challenging task because the streak artifacts with directional prominence are often hard to discriminate from the attenuation information of normal tissues. This paper describes a two-step processing scheme called ‘artifact suppressed large-scale nonlocal means’ for suppressing both noise and artifacts in thoracic LDCT images. Specific scale and direction properties were exploited to discriminate the noise and artifacts from image structures. Parallel implementation has been introduced to speed up the whole processing by more than 100 times. Phantom and patient CT images were both acquired for evaluation purpose. Comparative qualitative and quantitative analyses were both performed that allows conclusion on the efficacy of our method in improving thoracic LDCT data.