Cheong Haris, Krishna Devalla Sripad, Chuangsuwanich Thanadet, Tun Tin A, Wang Xiaofei, Aung Tin, Schmetterer Leopold, Buist Martin L, Boote Craig, Thiéry Alexandre H, Girard Michaël J A
Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore.
Biomed Opt Express. 2021 Feb 19;12(3):1482-1498. doi: 10.1364/BOE.412156. eCollection 2021 Mar 1.
Speckle noise and retinal shadows within OCT B-scans occlude important edges, fine textures and deep tissues, preventing accurate and robust diagnosis by algorithms and clinicians. We developed a single process that successfully removed both noise and retinal shadows from unseen single-frame B-scans within 10.4ms. Mean average gradient magnitude (AGM) for the proposed algorithm was 57.2% higher than current state-of-the-art, while mean peak signal to noise ratio (PSNR), contrast to noise ratio (CNR), and structural similarity index metric (SSIM) increased by 11.1%, 154% and 187% respectively compared to single-frame B-scans. Mean intralayer contrast (ILC) improvement for the retinal nerve fiber layer (RNFL), photoreceptor layer (PR) and retinal pigment epithelium (RPE) layers decreased from 0.362 ± 0.133 to 0.142 ± 0.102, 0.449 ± 0.116 to 0.0904 ± 0.0769, 0.381 ± 0.100 to 0.0590 ± 0.0451 respectively. The proposed algorithm reduces the necessity for long image acquisition times, minimizes expensive hardware requirements and reduces motion artifacts in OCT images.
光学相干断层扫描（OCT）B 扫描中的斑点噪声和视网膜阴影会遮挡重要边缘、精细纹理和深层组织，阻碍算法和临床医生进行准确可靠的诊断。我们开发了一个单一流程，能够在 10.4 毫秒内成功从未经处理的单帧 B 扫描中去除噪声和视网膜阴影。所提算法的平均梯度幅值（AGM）比当前最先进技术高 57.2%，而与单帧 B 扫描相比，平均峰值信噪比（PSNR）、对比度噪声比（CNR）和结构相似性指数测量值（SSIM）分别提高了 11.1%、154%和 187%。视网膜神经纤维层（RNFL）、光感受器层（PR）和视网膜色素上皮（RPE）层的平均层内对比度（ILC）改善分别从 0.362±0.133 降至 0.142±0.102、从 0.449±0.116 降至 0.0904±0.0769、从 0.381±0.100 降至 0.0590±0.0451。所提算法减少了长时间图像采集的必要性，将昂贵的硬件需求降至最低，并减少了 OCT 图像中的运动伪影。
