The 24-hour uptake of I131 by the thyroid gland does not always reflect the true clinical picture of thyroid disease. Hence, additional confirmatory tests were introduced in order to clarify the discrepancies. This presentation correlates the 24-hour I131 uptake, salivary tests, and conversion ratios with the clinical status of a group of euthyroid, hyperthyroid, and hypothyroid patients diagnosed by history, physical examination, and other laboratory procedures.
This study included 164 patients referred for thyroid evaluation. Each patient was thoroughly investigated clinically. None of the patients had any previous radioiodine therapy. The 24-hour I131 uptake, conversion ratio, and salivary count were done 24 hours after the oral administration of about 50μc of I131 in 25 cc. of tap water.The tracer doses of I were accurately measured in terms of microcuries, using a modified Braestrup ionization chamber and linear electrometer circuit calibrated with a 20γ U. S.