THE TEN-MINUTE UPTAKE OF I131: A CLINICAL STUDY AND COMPARISON WITH OTHER TESTS OF THYROID FUNCTION

Abstract

The value of estimating the ten-minute uptake of I131 by the thyroid was studied in 333 cases. In hyperthyroidism the deviation from normal values was greater than with the 24-hour uptake. In some mild but definite cases of hyperthyroidism, the ten-minute uptake was clearly abnormal when the 24-hour uptake was normal. The reverse did not occur. In Graves'' disease the deviation from normal of the ten-minute uptake was greater than the deviation from normal of the serum protein-bound iodine level, whereas in toxic nodular goiter the degree of elevation above normal of the two values was comparable. Among 221 patients without thyroid disorders, in only 1 was the ten-minute thyroidal uptake of I131 above the normal range. One of 33 patients with Graves'' disease, and 3 of 20 patients with toxic nodular goiter had ten-minute uptakes in the normal range. The short duration of the test renders it practicable, and allows its adaptation to the use of I132. It does not distinguish iodine deficiency from hyperthyroidism; it is useless in the diagnosis of hypothyroidism, and suffers the slight disadvantage of requiring an intravenous injection.