TC-99M AND I-131 THYROID SCINTIGRAPHY IN NORMAL AND RADIOTHYROIDECTOMIZED COCKATIELS (NYMPHICUS-HOLLANDICUS)

Thyroid scintigraphy using sodium Technetium-99m pertechnetate (TcO4-) -Tc-99 was performed in normal and radiothyroidectomized cockatiels (N ymphicus hollandicus). I-131 scintigraphy was performed in the course of ablating the thyroid glands. The thyroid glands in normal birds wer e clearly visualized, but were not individually resolvable. Thyroid gl ands were not visualized in thyroid-ablated birds. With (TcO4-)-Tc-99m scans, thyroid (or other region of interest)/body count density ratio s were used for comparisons of normal and thyroid-ablated birds. Norma l (TcO4-)-Tc-99m thyroid/body ratios (mean +/- SD) for the dorsal and lateral views were 1.83 +/- 0.31 and 1.70 +/- 0.34 respectively. Perte chnetate thyroid/body count density ratios decreased (to 0.93 +/- 0.14 and 0.88 +/- 0.12 for dorsal and lateral views respectively) after th yroid ablation, while crop/body ratios increased. (TcO4-)-Tc-99m thyro id scintigraphy, therefore, was capable of detecting hypofunctional th yroid abnormalities in I-131 radiothyroidectomized cockatiels.