Contour analysis of endoscopic images in the diagnosis of early gastric cancer

The purpose of the study: The main purpose of the study is creation of a system for digital processing of endoscopic images in white light and narrow band imaging for the early diagnosis of early forms of stomach cancer.

Materials and methods: The object of the study is endoscopic images (6320 cases) with PENTAX EG-2790K and OLYMPUS H180 devices. The subjects of the research are mathematical models of gastric epithelial neoplasias, classifi cation of these tissues, methods of digital image processing and contour analysis, methods of mathematical modeling.

Results: The work is divided into two stages to obtain quantitative estimates of the studied characteristics: 1. To make a diagnostic map — the image is segmented, then the boundaries between the pathologically altered tissues and the normal mucous membrane are drawn. 2. The calculation of the characteristics of the contour associated with diagnostic signs is made. As a measure of the symmetry of the figure, the symmetry coefficient k was used, defined as the ratio of the number of samples of the normalized autocorrelation function that exceeded the specified threshold in level to the total number of samples. The study revealed that the contours of malignant neoplasms have a symmetry coefficient k < 0,05, and the contours of benign neoplasms k > 0,2. This suggests the possibility of automated differentiation of neoplasms based on the analysis of their shape.

The conclusion: An objective assessment of endoscopic signs of early gastric cancer is necessary to standardize and systematize the diagnostic approach. The unified digital processing of endoscopic images will allow the endoscopist to increase the frequency of detecting early forms of gastric cancer, which will affect to reduce mortality.

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