College of Information Management, Nanjing Agricultural University, Nanjing, 210095, China; School of Information Engineering, Shandong Huayu University of Technology, Dezhou, 253034, China.
School of Information Engineering, Shandong Huayu University of Technology, Dezhou, 253034, China.
Comput Methods Programs Biomed. 2022 Nov;226:107101. doi: 10.1016/j.cmpb.2022.107101. Epub 2022 Sep 10.
Currently, the morbidity and mortality of lung cancer rank first among malignant tumors worldwide. Improving the resolution of thin-slice CT of the lung is particularly important for the early diagnosis of lung cancer screening.
Aiming at the problems of network training difficulty and low utilization of feature information caused by the deepening of network layers in super-resolution (SR) reconstruction technology, we propose the dual attention mechanism network for single image super-resolution (SISR). Firstly, the feature of a low-resolution image is extracted directly to retain the feature information. Secondly, several independent dual attention mechanism modules are constructed to extract high-frequency details. The introduction of residual connections can effectively solve the gradient disappearance caused by network deepening, and long and short skip connections can effectively enhance the data features. Furthermore, a hybrid loss function speeds up the network's convergence and improves image SR restoration ability. Finally, through the upsampling operation, the reconstructed high-resolution image is obtained.
The results on the Set5 dataset for 4 × enlargement show that compared with traditional SR methods such as Bicubic, VDSR, and DRRN, the average PSNR/SSIM is increased by 3.33 dB / 0.079, 0.41 dB / 0.007 and 0.22 dB / 0.006 respectively. The experimental data fully show that DAMN can better restore the image contour features, obtain higher PSNR, SSIM, and better visual effect.
Through the DAMN reconstruction method, the image quality can be improved without increasing radiation exposure and scanning time. Radiologists can enhance their confidence in diagnosing early lung cancer, provide a basis for clinical experts to choose treatment plans, formulate follow-up strategies, and benefit patients in the early stage.
目前,肺癌的发病率和死亡率在全球恶性肿瘤中位居首位。提高肺部薄层 CT 的分辨率对于肺癌筛查的早期诊断尤为重要。
针对超分辨率(SR)重建技术中网络加深导致的网络训练困难和特征信息利用率低的问题,提出了一种用于单图像超分辨率(SISR)的双注意力机制网络。首先,直接提取低分辨率图像的特征,保留特征信息。其次,构建了几个独立的双注意力机制模块,以提取高频细节。引入残差连接可以有效地解决网络加深导致的梯度消失问题,长、短跳跃连接可以有效地增强数据特征。此外,混合损失函数可以加快网络的收敛速度,提高图像 SR 恢复能力。最后,通过上采样操作得到重建的高分辨率图像。
在 Set5 数据集上进行 4 倍放大的结果表明,与传统的 SR 方法(如 Bicubic、VDSR 和 DRRN)相比,平均 PSNR/SSIM 分别提高了 3.33dB/0.079、0.41dB/0.007 和 0.22dB/0.006。实验数据充分表明,DAMN 可以更好地恢复图像轮廓特征,获得更高的 PSNR、SSIM 和更好的视觉效果。
通过 DAMN 重建方法,可以在不增加辐射暴露和扫描时间的情况下提高图像质量。放射科医生可以增强对早期肺癌诊断的信心,为临床专家选择治疗方案、制定随访策略提供依据,并使早期患者受益。