Final answer:
Medullary thyroid carcinoma can be diagnosed using a PET scan with 18-FDG, a Gallium-67 scan, and blood tests for thyroid hormone levels to confirm the presence of the disease.
Step-by-step explanation:
The diagnosis of Medullary thyroid carcinoma (MTC) involves various tests beyond initial thyroid scans using iodine isotopes like Na¹³¹I or Na¹²³I, which are commonly used for evaluation of thyroid function. In the context of MTC, additional diagnostic measures can include a positron emission tomography (PET) scan using 18-fluorodeoxyglucose (18-FDG), as it may help in identifying metastatic disease due to its ability to trace glucose metabolism, which is often increased in cancer cells. Another test that can be utilized is a Gallium-67 scan because Gallium-67 tends to accumulate in areas of rapid cell growth, such as tumors. These diagnostics are supplemented by blood tests to measure levels of thyroid hormones and other related markers to achieve a conclusive diagnosis.