基于形变场灰度场插值网络的切片间超分辨率  

Inter-slice Super-resolution Based on Deformation Field and Grey Field Interpolation Networks

作　　者：刘迅 张东[1] 袁达龙 LIU Xun;ZHANG Dong;YUNG Da-long(School of Physics and Technology,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学物理科学与技术学院,湖北武汉430072

出　　处：《计算机与现代化》2024年第3期67-71,共5页Computer and Modernization

基　　金：国家重点研发计划项目(2011CB707900)。

摘　　要：磁共振成像是一种常见的医学影像方法。由于硬件等因素的限制,MR图像切片间分辨率会远低于切片内分辨率,图像的质量较低,影响医生对患者病情的诊断,因此需要提高切片间分辨率,以便显示图像更多的细节。为了实现切片间超分辨率,提出一种基于非参数化形变场和灰度场插值网络的算法。首先,根据图像配准原理,利用近似U-Net的网络对低分辨率图像中2张相邻切片进行无监督训练,以生成切片间的双向形变场。然后,利用第一张切片与形变场生成配准后的图像,将配准后的图像与第二张切片进行训练,得到它们之间的双向灰度场,由此得到相邻2张切片中间任意位置的形变场和灰度场。最后,利用插值的方法获得中间的任一位置切片。与其他现有的算法相比,该算法在视觉效果和客观评价指标上都有显著提升,其中PSNR和SSIM分别均在30 dB和0.99以上。Magnetic resonance imaging is a widely used medical imaging method.Constrained by hardware conditions and other factors,the inter-slice resolution of MR images is much lower than the intra-slice resolution,resulting in low image quality and affecting the doctor’s diagnosis of the patient’s condition.Therefore,it is necessary to improve the inter-slice resolution to dis⁃play more details of the image.In order to achieve super resolution between slices,an algorithm based on non-parametric defor⁃mation field and gray field interpolation network is proposed.Firstly,according to the principle of image registration,an approxi⁃mate U-Net network is used for unsupervised training of two adjacent slices in low-resolution images to generate bidirectional de⁃formation fields between slices.Then,the registered image is generated by using the first slice and the deformation field,and the registered image and the second slice are trained to obtain the bidirectional gray field between them,from which the deformation field and gray field at any position in the middle of the adjacent two slices can be obtained.Finally,any position slice in the middle can be obtained by interpolation method.Compared to other existing algorithms,this algorithm has significant improve⁃ment in visual effect and objective evaluation index,with PSNR and SSIM above 30 dB and 0.99,respectively.

关 键 词：磁共振成像 超分辨率 形变场 灰度场 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]