Why should iodine uptake tests not be abandoned

Sine Iodine 132 has a too short half-life to be of value for the evaluation of hypothyroidism whereas Iodine 123, with a half-life of 12 hours and an ideal gamma energy, is too expensive for routine work, and has a too short shelf-life, some centers use Tc 99m for the evaluation of hyperthyroidism, and others have abandoned the uptake test altogether, relying entirely on in vitro tests. The intention of this paper is to show that the Iodine uptake test still remains the most useful test for the diagnosis of thyroid disorders, especially hypothyroidism. Relying only on in vitro tests could conduce to an incorrect diagnosis. (B.G.)