摘要
基于回波平面成像(echo planar image,EPI)序列的功能磁共振成像(functional magnetic resonance imaging,fMRI)是当前基础与临床脑功能研究实现快速成像的主要手段。但是,与常规成像序列相比,这种快速成像更容易受到各种噪声和伪影的干扰,从而影响fMRI的数据质量。如何及时发现和解决EPI的伪影和稳定性问题,是fMRI科研数据质量控制的一个核心问题。本文对笔者在过去五年fMRI质量控制工作中发现的成像问题进行整理,总结了fMRI应用中经常遇到的五种主要伪影,包括奈奎斯特鬼影、几何畸变、尖峰噪声、射频噪声和EPI稳定性相关的问题。并为每种伪影选取了具有代表性的案例,分析它们的特点、主要成因和应对方案。希望这些案例和分析结果能为fMRI用户和技术人员提供有益的借鉴。
Functional magnetic resonance imaging （fMRI） based on echo planar image （EPI） sequence is the major tool in basic and clinical brain function research. However, compared with the routine imaging sequence, EPI is much easier to suffer from the noises and artifacts, which affects the quality of fMRI data. So how to detect and resolve the artifacts and stability problem of EPI has become a core issue of fMRI quality control for research. In this paper, five types of fMRI artifacts are summarized and reviewed, which often occur in the application of fMRI based on authors’ 5 years experience of fMRI quality control. They are the Nyquist ghost, geometric distortion, spike noise, RF noise and stability problems in the time course. The selected cases, found in fMRI quality control process, are adopted for each type of artifact for further analysis including its feature, major causes and trouble shooting guideline. We expect that these cases and their detailed analysis can be good references for the researchers and technicians to assure the quality of their fMRI data.
出处
《磁共振成像》
CAS
2012年第2期144-148,共5页
Chinese Journal of Magnetic Resonance Imaging
基金
国家自然科学基金(项目编号:81171318)资助
关键词
功能磁共振成像
回波平面成像
伪影
鬼影
质量控制
Functional magnetic resonance imaging
Echo planar image
Artifact
Ghost
Quality Control
