Extraction of stomach region from barium-filled stomach image by a feedback method

The method is described of extracting the stomach region from the upright X-ray barium-filled stomach image in group examination. The approximate stomach region is obtained through the light intensity and its differentiation. Values of the parameters in this procedure are first obtained from statistics of the overall image light intensity. If the stomach region is inappropriate, the procedure is repeated by changing the parameter values. By this feedback, apparent error is avoided, so that an approximate stomach region is obtained for variety of the objectives. Subsequently, main parts of the stomach are determined and the overapping intestines are separated. Finally, the exact boundary is determined on the basis of local light intensity at the boundary of the approximate stomach region. In an experiment with the X-ray photographs taken randomly, the valid result could be obtained. (Mori, K.)