Nagy Szilvia, Sziová Brigita, Pipek János
Széchenyi István University, Egyetem tér 1, H-9026 Gyor, Hungary.
Budapest University of Technology and Economics, Budafoki út 8, H-1111 Budapest, Hungary.
Entropy (Basel). 2019 Mar 6;21(3):256. doi: 10.3390/e21030256.
Colonoscopy is the standard device for diagnosing colorectal cancer, which develops from little lesions on the bowel wall called polyps. The Rényi entropies-based structural entropy and spatial filling factor are two scale- and resolution-independent quantities that characterize the shape of a probability distribution with the help of characteristic curves of the structural entropy-spatial filling factor map. This alternative definition of structural entropy is easy to calculate, independent of the image resolution, and does not require the calculation of neighbor statistics, unlike the other graph-based structural entropies.The distant goal of this study was to help computer aided diagnosis in finding colorectal polyps by making the Rényi entropy based structural entropy more understood. The direct goal was to determine characteristic curves that can differentiate between polyps and other structure on the picture. After analyzing the distribution of colonoscopy picture color channels, the typical structures were modeled with simple geometrical functions and the structural entropy-spatial filling factor characteristic curves were determined for these model structures for various parameter sets. A colonoscopy image analying method, i.e., the line- or column-wise scanning of the picture, was also tested, with satisfactory matching of the characteristic curve and the image.
结肠镜检查是诊断结直肠癌的标准手段,结直肠癌由肠壁上称为息肉的小病变发展而来。基于雷尼熵的结构熵和空间填充因子是两个与尺度和分辨率无关的量,它们借助结构熵-空间填充因子图的特征曲线来表征概率分布的形状。这种结构熵的替代定义易于计算,与图像分辨率无关,并且与其他基于图形的结构熵不同,不需要计算邻域统计量。本研究的长远目标是通过使基于雷尼熵的结构熵更容易理解,来帮助计算机辅助诊断发现结直肠息肉。直接目标是确定能够区分息肉和图片上其他结构的特征曲线。在分析了结肠镜检查图片颜色通道的分布后,用简单几何函数对典型结构进行建模,并针对这些模型结构在各种参数集下确定了结构熵-空间填充因子特征曲线。还测试了一种结肠镜图像分析方法,即逐行或逐列扫描图片,特征曲线与图像的匹配效果令人满意。