Table 2. Serum TSH level and Ug FNB If the serum TSH level is depressed, the findings of a radionuclide thyroid scan should be correlated with  those of U/S. If the nodule of interest is hot, an Ug FNB is contraindicated.   If the serum TSH is normal or elevated, an U/S should be performed to determine if sonographic criteria for Ug FNB are met and if the nodule should be biopsied. Incidentally discovered thyroid nodules an Ug FNB neednot be delayed if the patient is undergoing sonography and the results of the serum TSH level are not available. References: 10-13