Comparison of Scintigraphy and CT-scan techniques in the diagnosis of cat hyperthyroidism

Hyperthyroidism is one of the common diseases in felines. For confirming this disease, the scintigraphy technique can be used. In Iran, the use of the scintigraphy method is not common due to the limited access to radiopharmaceuticals, gamma cameras, and keeping of animals following scintigraphy due to the excretion of radioactive material. This study aimed to evaluate the possibility of diagnosing this disease using CT scan technique is an alternative compared to scintigraphy. 19 cats suspected of hyperthyroidism were used in this study. Each of the animals was examined using blood samples to check thyroid hormones. Then the scintigraphy has done and after that, they were isolated for 24 hours to dispose of the radiopharmaceutical. Finally, the thyroid gland of the animals was examined by CT scan and the results of the tests were compared with each other. Statistically, there was no significant difference between the parameters obtained from the blood serum hormone and the parameters obtained from the CT scan, such as length, width, height, volume, heterogeneity, and radiation attenuation, between the two patient and healthy groups. However, the scintigraphy parameters of the two groups contains healthy and patients, such as the density ratio of the thyroid gland to the salivary glands density, as well as the thyroid gland density to the background area, had statistically significant differences. The results of this study showed that it is not possible to diagnose hyperthyroidism in cats using the CT scan technique as an alternative to the scintigraphy technique.