摘要
医学图像的质量对于患者疾病的诊断、治疗乃至科学研究起着重要的作用.然而,受医疗设备和放射剂量等因素的影响,医学CT图像的分辨率普遍较低.为了实现医学CT图像超分辨重建,提出一种结合反卷积的神经网络算法,通过引入反卷积操作,有效地建立了低/高分辨率图像之间端到端的映射.首先选取肺部、脑部、心脏和脊椎等部位的1 500幅CT图像作为训练数据,将训练数据下采样后输入网络模型;然后建立正反卷积网络模型学习图像特征,网络模型用caffe框架实现,激活函数使用PReLU;最后基于学习到的这些特征重建出高分辨率图像,采用平均方法重建图像.实验结果表明,文中算法能够更好地重建出图像的轮廓和边缘纹理;与已有算法相比,所构建的4层网络结构在重建结果的峰值信噪比、结构相似性、信息熵及重建速度等性能指标上均取得了更好的效果.
The quality of medical images plays an important role in the diagnosis,treatment and even scientific research of patients’diseases.However,due to the influence of medical equipment and radiation dose,the resolution of medical CT images is generally low.Therefore,this paper proposes a neural network algorithm combined with deconvolution for achieving super-resolution reconstruction of medical CT images.The proposed algorithm adds the operation of deconvolution,which effectively establishes the end-to-end mapping between low and high-resolution images.Firstly,1 500 CT images of lung,brain,heart and spine are selected as training data,and they are down-sampled and then input into network model.Secondly,through the establishment of the convolution and deconvolution network model to learn image features,the network model is implemented using the caffe framework,and the activation function uses PReLU.Finally,the algorithm reconstructs high-resolution images using these features,where the image of reconstruction are averaged.The experimental results show that the proposed algorithm can reconstruct the contour and edge texture of the image better.Compared with the traditional super-resolution algorithm,the constructed four-layer network in this paper achieves better results in peak signal-to-noise ratio(PSNR),structural similarity(SSIM),information entropy(IE)and reconstruction speed.
作者
徐军
刘慧
郭强
张彩明
Xu Jun;Liu Hui;Guo Qiang;Zhang Caiming(School of Computer Science and Technology,Shandong University of Finance and Economics,Ji’nan 250014;Digital Media Technology Key Laboratory of Shandong Province,Ji’nan 250014;School of Computer Science and Technology,Shandong University,Ji’nan 250100;Shandong Co-Innovation Center of Future Intelligent Computing,Yantai 264025)
出处
《计算机辅助设计与图形学学报》
EI
CSCD
北大核心
2018年第11期2084-2092,共9页
Journal of Computer-Aided Design & Computer Graphics
基金
国家自然科学基金重点项目浙江联合基金(U1609218)
国家自然科学基金(61572286
61472220)
山东省重点研发计划(2017CXGC1504)
山东省自然科学基金(ZR2017JL029)
山东省高等学校优势学科人才团队培育计划
关键词
CT图像
超分辨重建
卷积神经网络
反卷积
PReLU
CT image
super-resolution reconstruction
convolution neural network
deconvolution
PReLU
