Abstract
One of the most valuable diagnostic procedures in the field of Radiology is the examination of the upper GI tract by means of an opaque media. Cannon was the first to study the upper GI tract. He studied the movements of the stomach and intestines on cats after the injection of food and bismuth paste mixture. Since Cannon's work, which was done in the latter part of the 19th century, the method of upper GI tract examination has been" improved, almost to the point of perfection, by the outstanding work of our physicists, technicians and radiologists. | Becher was the first to record his observations on the outline of the stomach and intestines of a guinea pig after feeding it a mixture containing lead acetate. He then decided, that to make further progress in this field, a solution must be used in the stomach, which will not harm this organ, and at the same time cast an opaque.shadow on a fluroscopic screen or x-ray film. Following this Rumpel outlined a dilated esophagus by filling it with a suspension of bismuth subnitrate.