Blood Levels of 1-131 after Tracer Doses in the Diagnosis of Hyperthyroidism

Abstract

Present methods of using I131 in the diagnosis of thyroid disorders are unsatisfactory. In a consecutive series of 24 normals and 30 hyperthyroids it is shown that blood levels of I131 at 72 hrs. after tracer doses of 100 microcuries provide a sharp differentiation of the 2 groups. There is an avg. of more than 10 times the radioactivity in the blood of the hyperthyroids than in the blood of normals, and this activity is due to protein bound I131. The Q-gas counter, Model D 46, Nuclear Instrument Co., Chicago, was used. This method provides the best diagnostic procedure now available.