应用腹平片结合电脑图像处理技术进行肠道气体的定量分析

Quantitative analysis of bowel gas by plain abdominal radiograph combined with computer image processing

目的 探讨应用腹平片及电脑图像处理技术定量分析肠道气体的可行性。方法2 5名肠易激综合征 (irritablebowelsyndrome ,简称IBS)患者及 2 0名正常志愿者的X线腹平片由 1名放射科医师及 1名消化科医师独自勾画出界定矩形框内 (第 10胸椎下缘水平线及耻骨联合上缘水平线相交于髂前上嵴垂线 )的肠气轮廓 ,用数码相机将胶片数字化 ,输入计算机 ,利用Histogram功能计算指定范围像素值 ,以肠气像素值与矩形框像素值之比表示肠气量 ,即气体容积积分 (GVS)。比较 2名医师的测定结果。正常组中 5例在 1周后重复摄片 ,比较前后 2次的GVS值 ,了解重复性。结果 腹平片清晰显示肠气 ,大小肠均在所设矩形框内 ;放射科医师及消化科医师均能在 10min内完成测定 ,2名医师测定结果具有高度一致性 ,相关系数r=0 986,重复摄片的 5例前后 2次的GVS值差异无显著性意义 (t=0 2 85 ,P >0 0 5 )。结论 本实验方法能间接定量反映肠气 ,具有简单、快捷。

Objective To establish a method for quantitative analysis of bowel gas by plain abdo minal radiograph and computer graphics. Methods Plain abdo minal radiographs in supine position from 25 patients with irritable bowel syndrome (IBS) and 20 health controls were studied. A gastroenterologist and a radiologist independently conducted the following procedure on each radiograph. After the outline of bowel gas was traced by axe pen, the radiograph was digitized by a digital camera and transmitted to the computer with Histogram software. The total gas area was deter mined as the pixel value on images. The ratio of the bowel gas quantity to the pixel value in the region surrounded by a horizontal line tangential to the superior pubic symphysis margin, a horizontal line tangential to the tenth dorsal vertebra inferior margin, and the lateral line tangential to the right and left anteriosuperior iliac crest, was defined as the gas volume score (GVS). To exa mine the sequential reproducibility, a second plain abdo minal radiograph was performed in 5 normal controls 1 week later, and the GVS were compared. Results Bowel gas was easily identified on the plain abdo minal radiograph. Both large and small intestine located in the selected region. Both observers could finish one radiographic measurement in less than 10 mins. The correlation coefficient between the two observers was 0.986. There was no statistical difference on GVS between the two sequential radiographs in 5 health controls. Conclusion Quantification of bowel gas based on plain abdo minal radiograph and computer is simple, rapid, and reliable.