摘要
扩散张量成像(Diffusion tensor image,DTI)是一种磁共振成像技术,可以提供白质纤维的走行等独特信息,且具有非侵入和不需要造影剂等优点,因此在理论研究和临床应用领域引起了极大的关注.然而在DTI成像过程中,由于受噪声的影响,导致获得的图像边缘信息模糊不清,给病灶的识别带来了难度.为了减少噪声对DTI图像的影响并且有效地保留边缘结构信息,通过结合结构张量和各向异性平滑技术提出一种新型的DTI去噪方法.首先利用结构张量将DTI图像中的像素分成均匀平坦区域和边缘轮廓区域,然后在均匀区域内进行各向同性滤波,而在边缘轮廓区域进行各向异性平滑处理,从而得到去噪后的DTI图像.实验结果表明,基于结构张量和各向异性平滑的DTI去噪方法明显降低了噪声的影响,同时有效地保留了图像的边缘结构信息.
Diffusion tensor image( DTI) is a magnetic resonance imaging technology that can provide unique information such as the white matter tractography,and has the advantages of non-invasive technique and requires no contrast medium. It is all the facts above have stirred great interest toward DTI in theory research and clinical application. However,in the procession of DTI imaging,due to the impact of noise,the edge information of the obtained image is blurred,which brings difficulty to the identification of diseases. In order to reduce the influence of noise on DTI image and preserve the edge information effectively,a newDTI denoising method is proposed by combining structure tensor and anisotropic smoothing technique. Firstly,the pixels of the DTI image are divided into homogeneous areas and edge regions by structure tensor. Then,the isotropic filtering is performed in the homogeneous region,and the anisotropic smoothing is performed in the edge region. Finally,the denoised DTI image is obtained. The experimental results showthat the DTI denoising method based on structure tensor and anisotropic smoothing can reduce the influence of noise significantly,and preserve the edge structure information of the DTI image effectively.
引文
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