An abdominal CT can give you an idea how the flat plate is taken and what is seen on the flat plate. The most common clinical question to be answered using an abdominal flat plate is mechanical bowel obstruction vs. adynamic ileus, to make this determination, we rely on changes in the pattern of gas in the bowel lumen, so it is important to be able to recognize both of these. The gas within the bowel provides a natural luncency that outlines the intestinal lumen. This is very useful in detecting abdominal disease.
Gas is usually present in stomach.
The small bowel may be partially filled with gas. Gas may also be seen throughout the entire colon. The outlines of soft tissue is made possible by radiolucent fat which surrounds intra-abdominal organs. These structures may not always be visible. Technical problems, such as overlying bowel gas, may obscure the liver's edge.