The radioisotopic technique has been recognized as the best method of measuring gastric emptying all over the world, but several problems which must be solved have remained in it.
The first is the confusion in the choice of a standard meal of ordinary food labeled with radioisotope. A meal for use in this studies must be reproducible in quality, and radioisotope must be homogenously distributed in it. It is necessary to consider the efficiency of examination, and to release a examinee's agony, therefore a meal must leave the stomach within the tolerable limits of a patient who keeps himself unshaken during measurement. If a liquid meal is used, we can easily make use of foods on the market. But, if a solid meal, a practical difficulty stands in front of us; Who prepares to cook it ? Unless this problem has been solved, the radioisotopic method is never found general acceptance as a clinical examination.
The second is the confusion in the choice of a posture during measurement. We must select such posture that never alter a patient's characteristics of his gastric emptying. For example, it is difficult to prove rapid evacuation in a patient with dumping syndrome, if we examine him in supine position.
A final problem is to re-examine what kinds of index are necessary to investigate the gastric emptying curve with many variations except of half-emptying time which has been used popularly as the index of the rate of it.
We gave an out-line of the methods of measuring gastric emptying using radioisotope and a suggestion of its some problems awaiting solution.