Summary
A large number of different radioisotopes have been used for measurement of disease conditions in the human body. They may measure liquid volumes, rates of flow or rates of transfer through organs or membranes; they may show the behavior of internal organs; they may differentiate between normal and malignant tissues. Hundreds of hospitals are now making thousands of these tests annually.
This does not mean that all the diagnostic problems have been solved. Much of the work is on an experimental rather than a routine basis. Improvements in techniques are still being made. As quantities of radioisotopes available for these purposes grow, and as the cost continues to drop, it is expected there will be still more applications. Finally, this does not mean we no longer need the doctor’s diagnostic skill. All radioisotope procedures are merely tools to aid the skilled physician. As the practice of medicine has changed from an art to a science, radioisotopes have played a useful part.