基于多感受野的生成对抗网络医学MRI影像超分辨率重建  

Medical MRI image super-resolution reconstruction based on multi-receptive field generative adversarial network

作　　者：刘朋伟 高媛[1,2,3] 秦品乐[1,2,3] 殷喆 王丽芳[1,2,3] LIU Pengwei;GAO Yuan;QIN Pinle;YIN Zhe;WANG Lifang(Shanxi Medical Imaging and Data Analysis Engineering Research Center(North University of China),Taiyuan Shanxi 030051,China;School of Data Science and Technology,North University of China,Taiyuan Shanxi 030051,China;Shanxi Medical Imaging Artificial Intelligence Engineering Technology Research Center(North University of China),Taiyuan Shanxi 030051,China)

机构地区：[1]山西省医学影像与数据分析工程研究中心(中北大学),太原030051 [2]中北大学大数据学院,太原030051 [3]山西省医学影像人工智能工程技术研究中心(中北大学),太原030051

出　　处：《计算机应用》2022年第3期938-945,共8页journal of Computer Applications

基　　金：山西省自然科学基金资助项目(201901D111152)。

摘　　要：针对医学磁共振成像(MRI)过程中由于噪声、成像技术和成像原理等干扰因素引起的图像细节丢失、纹理不清晰等问题,提出了基于多感受野的生成对抗网络医学MRI影像超分辨率重建算法。首先,利用多感受野特征提取块获取不同感受野下图像的全局特征信息,为避免感受野过小或过大导致图像的细节纹理丢失,将每组特征分为两组,其中一组用于反馈不同尺度感受野下的全局特征信息,另一组用于丰富下一组特征的局部细节纹理信息;然后,使用多感受野特征提取块构建特征融合组,并在每个特征融合组中添加空间注意力模块,充分获取图像的空间特征信息,减少了浅层和局部特征在网络中的丢失,在图像的细节上取得了更逼真的还原度;其次,将低分辨率图像的梯度图转化为高分辨率图像的梯度图辅助重建超分辨率图像;最终将恢复后的梯度图集成到超分辨率分支中,为超分辨率重建提供结构先验信息,有助于生成高质量的超分辨率图像。实验结果表明,相比基于梯度引导的结构保留超分辨率算法(SPSR),所提算法在×2、×3、×4尺度下的峰值信噪比(PSNR)分别提升了4.8%、2.7%、3.5%,重建出的医学MRI影像纹理细节更加丰富、视觉效果更加逼真。To solve the problems of image detail loss and unclear texture caused by interference factors such as noise,imaging technology and imaging principles in the medical Magnetic Resonance Imaging(MRI)process,a multi-receptive field generative adversarial network for medical MRI image super-resolution reconstruction was proposed.First,the multireceptive field feature extraction block was used to obtain the global feature information of the image under different receptive fields.In order to avoid the loss of detailed texture due to too small or too large receptive fields,each set of features was divided into two groups,and one of which was used to feedback global feature information under different scales of receptive fields,and the other group was used to enrich the local detailed texture information of the next set of features;then,the multi-receptive field feature extraction block was used to construct feature fusion group,and spatial attention module was added to each feature fusion group to adequately obtain the spatial feature information of the image,reducing the loss of shallow and local features in the network,and achieving a more realistic degree in the details of the image.Secondly,the gradient map of the low-resolution image was converted into the gradient map of the high-resolution image to assist the reconstruction of the super-resolution image.Finally,the restored gradient map was integrated into the super-resolution branch to provide structural prior information for super-resolution reconstruction,which was helpful to generate high quality super-resolution images.The experimental results show that compared with the Structure-Preserving Super-Resolution with gradient guidance(SPSR)algorithm,the proposed algorithm improves the Peak Signal-to-Noise Ratio(PSNR)by 4.8%,2.7% and 3.5% at ×2,×3 and ×4 scales,respectively,and the reconstructed medical MRI images have richer texture details and more realistic visual effects.

关 键 词：超分辨率 多感受野 空洞卷积 空间注意力机制 梯度图 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]