Abstract: CLINICAL APPLICATION OF REVERSE T_3 RADIOIMMUNOASSAY IN THYROIDAL DISEASES Wu Yingzhen;Luo Jia;Wu Guozhen（Chongqing University of Medical Sciences, Department of Nuclear Medicine, First Hospital, 630042）ABSRACT The change of rT_3 in 182 patients with thyroidal diseases before ， during and afteer treatment isstudied and compared with T_3，T_4． The results show that levels of rT_3 in untreated and unrecovered hy-perthyroidism higher than control values． Serum rT_3 slowly declines in patients with hyperthyredism re-covered after treatment with antithyroidal drugs．Serum rT_3 concentrations fell significantly in patientswith hypothyroidism. However，there is significant difference between treated group with recoveryand normal controls．The mechanism and signi ficance of results are discussed in detail． It is pointedout that the measurement of serum rT_3 may be considered as an effective method for evaluating the thy-roidal function and the effectiveness of medical treatment. Key words rT_3 hyperthyroidism hypothyroidism