Total thyroidal content of iodine in thyrotoxic patients measured by in vivo neutron activation analysis.

This paper describes an in vivo method for measuring total thyroidal iodine stores by activation analysis, its evaluation and measurements in thyrotoxic patients. There was good correlation between measurements of solutions of iodine and post-mortem thyroids by activation analysis and chemical analysis. Measurements in thyrotoxic patients showed low levels in untreated and treated (antithyroid drugs) patients and a marked increase in patients studied whilst in clinical remission. The practical importance of this method of measurement of thyroidal iodine stores is that it is a reliable in vivo measurement obtained at a single visit and should enable the definition of the relationship of thyroidal iodine stores to pathophysiology and prognosis.