基于Transformer的结构强化IVOCT导丝伪影去除方法

Guidewire artifact removal method of structure-enhanced IVOCT based on Transformer

为去除导丝伪影以提高血管内光学相干断层扫描(IVOCT)的图像质量,辅助医师更加准确地诊断心血管疾病,降低误诊及漏诊的概率,针对IVOCT图像结构信息复杂且伪影区域占比大的难点,提出一种采用生成对抗网络(GAN)架构的基于Transformer的结构强化网络(SETN)。首先,GAN的生成器在提取纹理特征的原始图像(ORI)主干生成网络的基础上,并联了RTV(Relative Total Variation)图像强化生成网络用于获取图像的结构信息;其次,在ORI/RTV图像的伪影区域重建过程中,引入了分别关注时/空间域信息的Transformer编码器,用于捕获IVOCT图像序列的上下文信息以及纹理/结构特征之间的关联性;最后,利用结构特征融合模块将不同层次的结构特征融入ORI主干生成网络的解码阶段,配合判别器完成导丝伪影区域的图像重建。实验结果表明,SETN的导丝伪影去除结果在纹理和结构的重建上均十分优秀。此外,导丝伪影去除后IVOCT图像质量的提高,对于IVOCT图像的易损斑块分割及管腔轮廓线提取任务均具有积极意义。

Improving the image quality of IntraVascular Optical Coherence Tomography(IVOCT)through guidewire artifact removal can assist physicians in diagnosing cardiovascular diseases more accurately,which reduces the probabilities of misdiagnosis and missed diagnosis.Aiming at the difficulties of complex structure information and a large proportion of artifact areas in IVOCT images,a Structure-Enhanced Transformer Network(SETN)using Generative Adversarial Network(GAN)architecture was proposed for guidewire artifact removal of IVOCT images.Firstly,based on the ORiginal Image(ORI)backbone generation network for extracting texture features,the generator of GAN was combined with RTV(Relative Total Variation)image enhanced generation network in parallel to obtain image structure information.Next,during the artifact area reconstruction of ORI/RTV image,Transformer encoders focusing on the temporal/spatial domain information respectively were introduced to capture the contextual information and the correlation between texture/structure features of IVOCT image sequence.Finally,the structural feature fusion module was used to integrate the structural features of different levels into the decoding stage of the ORI backbone generation network,so that the generator was cooperated with the discriminator for completing the image reconstruction of the guidewire artifact area.Experimental results show that the guidewire artifact removal results of SETN are excellent in both texture and structure reconstruction.Besides,the improvement of IVOCT image quality after guidewire artifact removal is positive for both vulnerable plaque segmentation and lumen contour extraction tasks of IVOCT image.