在磁共振成像过程中由于患者的运动会在图像中造成运动伪影,从而造成图像的退化,严重影响临床诊断.本文对M R I图像刚性平移运动伪影提出了一个改进的后处理方法:首先用谱平移理论消除频率编码方向平移运动;然后建立模糊模型表示图像的...在磁共振成像过程中由于患者的运动会在图像中造成运动伪影,从而造成图像的退化,严重影响临床诊断.本文对M R I图像刚性平移运动伪影提出了一个改进的后处理方法:首先用谱平移理论消除频率编码方向平移运动;然后建立模糊模型表示图像的背景并对其进行抑制,用数学形态学的方法确定图像的支撑域;最后以能量熵为收敛准则,用相位恢复算法对频率编码方向残余的子像素移动造成的伪影和相位编码方向的伪影进行消除.实验表明,应用本研究提出的方法能够明显地消除图像空间运动造成的伪影.展开更多
A numerical method that compensates image distortions caused by random fluctuations of the distance to an object in spectral-domain optical coherence tomography(SD OCT)has been proposed and verified experimentally.The...A numerical method that compensates image distortions caused by random fluctuations of the distance to an object in spectral-domain optical coherence tomography(SD OCT)has been proposed and verified experimentally.The proposed method is based on the analysis of the phase shifts between adjacent scans that are caused by micrometer-scale displacements and the subsequent compensation for the displacements through phase-frequency correction in the spectral space.The efficiency of the method is demonstrated in model experiments with harmonic and random movements of a scattering object as well as during in vivo imaging of the retina of the human eye.展开更多
文摘在磁共振成像过程中由于患者的运动会在图像中造成运动伪影,从而造成图像的退化,严重影响临床诊断.本文对M R I图像刚性平移运动伪影提出了一个改进的后处理方法:首先用谱平移理论消除频率编码方向平移运动;然后建立模糊模型表示图像的背景并对其进行抑制,用数学形态学的方法确定图像的支撑域;最后以能量熵为收敛准则,用相位恢复算法对频率编码方向残余的子像素移动造成的伪影和相位编码方向的伪影进行消除.实验表明,应用本研究提出的方法能够明显地消除图像空间运动造成的伪影.
基金the State task for IAP RAS(project No.0035-2019-0013)in part of method development by the Russian scientific foundation(project No.17-15-01507)in part of model experiments and setup creatingthe Russian Federal target program(project 14.610.21.0014 unique No.RFMEFI61017X0014)in part of retinal imaging experiments.
文摘A numerical method that compensates image distortions caused by random fluctuations of the distance to an object in spectral-domain optical coherence tomography(SD OCT)has been proposed and verified experimentally.The proposed method is based on the analysis of the phase shifts between adjacent scans that are caused by micrometer-scale displacements and the subsequent compensation for the displacements through phase-frequency correction in the spectral space.The efficiency of the method is demonstrated in model experiments with harmonic and random movements of a scattering object as well as during in vivo imaging of the retina of the human eye.
