Abstract
Summary
A method of counting at a distance over the thyroid was used in animal and human subjects. This method involves the shielding of the Geiger counter tube from all radiation except the thyroid gland, by enclosing the counter in a long lead tube opening over the thyroid. The statistical error inherent in long distance counting is thereby effectively reduced. Independent beta assays were done on the thyroids of 5 dogs and 1 human adult who were subjected to total thyroidectomy immediately after counting with the above technic. Comparison of radioactivity of these glands, as determined by beta assays and by long distance gamma counting, showed a maximal deviation of the order of 20%, with the majority agreeing within about 5%.
Suggestions are made regarding improvement of in vivo measurements such as employed in this technic.
Get full access to this article
View all access options for this article.