School of Science, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.
Department of Mathematics, Nanjing University, Nanjing, Jiangsu, China.
Med Phys. 2021 Nov;48(11):7099-7111. doi: 10.1002/mp.15201. Epub 2021 Sep 13.
Fully automatic lumen segmentation in intravascular optical coherence tomography (OCT) images can assist physicians in quickly estimating the health status of vessels. However, OCT images are usually degraded by residual blood, catheter walls, guide wire artifacts, etc., which significantly reduce the quality of segmentation. To achieve accurate lumen segmentation in low-quality images, we propose a novel segmentation algorithm named SPACIAL: Shape Prior generation and geodesic Active Contour Interactive iterAting aLgorithm, which is guided by an adaptively generated shape prior.
In this framework, the active contour evolves under the guidance of shape prior, while the shape prior is automatically and adaptively generated based on the active contour. The active contour and the shape prior interactively iterate each other, which can generate the adaptive shape prior and consequently lead to accurate segmentation results. In addition, a fast algorithm is introduced to accelerate the segmentation in 3D images.
The validity of the model is verified in 3240 images from 12 OCT pullbacks. The experimental results show satisfactory segmentation accuracy and time efficiency: the average Dice coefficient of SPACIAL is 93.6(2.4)%, and 5.7 times faster than that of the classical level set method.
The proposed SPACIAL can quickly and efficiently perform accurate lumen segmentation on low quality OCT images, which is of great importance to cardiovascular disease diagnosis . The SPACIAL method shows great potential in clinical applications.
在血管内光学相干断层扫描(OCT)图像中实现全自动管腔分割,可以帮助医生快速评估血管的健康状况。然而,OCT 图像通常会因残留血液、导管壁、导丝伪影等因素而退化,从而显著降低分割质量。为了在低质量图像中实现准确的管腔分割,我们提出了一种名为 SPACIAL 的新型分割算法:形状先验生成和测地线主动轮廓交互迭代算法,该算法由自适应生成的形状先验引导。
在该框架中,主动轮廓在形状先验的引导下演变,而形状先验则根据主动轮廓自动和自适应生成。主动轮廓和形状先验相互迭代,从而可以生成自适应的形状先验,进而得到准确的分割结果。此外,引入了一种快速算法来加速 3D 图像的分割。
该模型在 12 次 OCT 拉回中 3240 张图像上进行了验证。实验结果表明分割精度和时间效率均令人满意:SPACIAL 的平均 Dice 系数为 93.6(2.4)%,比经典水平集方法快 5.7 倍。
所提出的 SPACIAL 可以快速有效地对低质量的 OCT 图像进行准确的管腔分割,这对心血管疾病的诊断具有重要意义。SPACIAL 方法在临床应用中具有很大的潜力。