基于深度模糊学习的牙科CBCT运动伪影校正算法

A deep blur learning-based motion artifact reduction algorithm for dental cone-beam computed tomography images

目的 针对牙科CBCT扫描中患者不自主运动导致的重建图像运动伪影问题,提出了一种基于深度模糊学习的牙科CBCT运动伪影校正算法(DMBL),以提升牙科CBCT的成像质量。方法 首先使用模糊编码模块提取运动退化特征,从而对运动导致的退化过程进行建模,然后将得到的运动退化特征输入伪影校正模块进行运动伪影去除。其中,伪影校正模块采用了图像模糊去除和图像模糊仿真的联合学习框架,可有效处理空间变化且随机的运动模式。为验证所提方法的有效性,本文分别在仿真运动数据集和临床数据集上进行对比实验。结果 仿真数据集实验结果表明,本文方法峰值信噪比提升了2.88%,结构相似性(SSIM)提升了0.89%,均方根误差(RMSE)减少了10.58%;临床数据集实验结果表明,本文方法取得了最高的专家主观图像质量评分4.417(5分制),且与对比方法结果的评分具有显著性差异(P<0.001)。结论 本文提出的DMBL算法,通过构建深度模糊联合学习网络结构,能够有效地去除牙科CBCT图像中的运动伪影,实现高质量的图像恢复。

Objective We propose a motion artifact correction algorithm(DMBL)for reducing motion artifacts in reconstructed dental cone-beam computed tomography(CBCT)images based on deep blur learning.Methods A blur encoder was used to extract motion-related degradation features to model the degradation process caused by motion,and the obtained motion degradation features were imported in the artifact correction module for artifact removal.The artifact correction module adopts a joint learning framework for image blur removal and image blur simulation for treatment of spatially varying and random motion patterns.Comparative experiments were conducted to verify the effectiveness of the proposed method using both simulated motion data sets and clinical data sets.Results The experimental results with the simulated dataset showed that compared with the existing methods,the PSNR of the proposed method increased by 2.88%,the SSIM increased by 0.89%,and the RMSE decreased by 10.58%.The results with the clinical dataset showed that the proposed method achieved the highest expert level with a subjective image quality score of 4.417(in a 5-point scale),significantly higher than those of the comparison methods.Conclusion The proposed DMBL algorithm with a deep blur joint learning network structure can effectively reduce motion artifacts in dental CBCT images and achieve high-quality image restoration.