目标与方法

Hp根除的胃黏膜图像特征是地图样发红。在本系统中，我们量化了LCI模式下胃黏膜的这种地图样发红图像，并提高了Hp阳性或阴性（根除后）诊断的准确性。通过使用LCI模式观察，地图样发红表现为薰衣草紫色，背景胃黏膜为杏色。图1显示了具有地图样发红的图像。首先，提取图像上具有薰衣草紫色的高色调值的区域作为感兴趣区域（ROI）。其次，在图像上确定ROI的重心。然后，以ROI的最外层像素到重心的欧氏距离为半径的圆被描绘为感兴趣的圆（COI）。最后，如果观察到图像的像素具有高ROI比率且在COI中具有大的色调方差值，则将其识别为具有地图样发红的图像。在胃黏膜图像中检测到地图样发红的病例被视为无菌和Hp阴性。图2用图表说明了传统方法和建议方法。在本研究中，使用朝日大学医院的200张内镜检查（LCI观察）图像（共40例；32例Hp阳性，8例根除后）并对该系统进行评估。结果，常规检查中，40例患者中有29例诊断正确。相比之下，通过使用开发的系统，40例患者中有37例得到了正确诊断。这些结果表明，量化地图样发红（Hp根除的特征）可提高系统的准确性。

Aims and methods: The characteristic of a gastric mucosa image, representing Hp eradication, is to have a map-like redness. In the proposed system, we quantify this map-like redness for images of gastric mucosa obtained from LCI, and improve the accuracy of diagnosis of Hp positive or negative (post eradication). By using LCI, the map-like redness is observed as lavender color, while background gastric mucosa is observed as apricot color. Figure 1 shows an image with map-like redness. First, a region on the image having a high hue value indicating a lavender color is extracted as a region of interest (ROI). Second, the center of gravity of the ROI is identified on the image. Thereafter, a circle, of radius equivalent to the Euclidean distance of the outermost pixel of the ROI from the center of gravity, is depicted as a circle of interest (COI). Finally, if an image having a high ROI ratio for all pixels and a large hue variance value in the COI is observed, it is identified as an image having map-like redness. Cases where map-like redness is detected in the gastric mucosa image, are considered as sterile and Hp negative. Figure 2 shows a schematic diagram of the conventional system and the proposed method. In this study, 200 images (40 cases; 32 cases are Hp positive and 8 cases are after eradication) of endoscopic examination (LCI observation) at Asahi University Hospital were used to evaluate the system. Result In the conventional system, 29 of the 40 cases were correctly diagnosed. In comparison, by using the proposed system, 37 of the 40 cases were correctly diagnosed. These results show that quantification of the map-like redness, which is characteristic of Hp eradication, leads to an improvement in the accuracy of the system.