Iodine-129 as a "nonradioactive" tracer.
D000201:Activation Analysis; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D011874:Radiometry; D013960:Thyroid Function Tests; D013970:Thyronines; D014284:Triiodothyronine
D007457:Iodine Radioisotopes; D013970:Thyronines; D014284:Triiodothyronine