 Carotid duplex -7% 3  USG neck -2% -15% 5  CT scan -4% -11% 6  PET Scan -30% -40%. 4,7,8 Solid thyroid nodules more than 1 cm in size should undergo ultrasound-guided fine-needle aspiration biopsy according to American Thyroid Association guidelines. Consideration for biopsy of thyroid nodules less than 1 cm should be restricted to nodules with atypical USG characteristics and potential nodules that are positive on PET scan due to their higher rate of malignancy. ABSTRACTBackground: Incidental thyroid nodules are typically non-palpable thyroid nodules found during radiographic evaluation for a non-thyroid related issue (USG neck, CT scan, PET scan, carotid duplex).The prevalence of thyroid incidentalomas ranges from 1.6% to 67% based on radiographic modality of detection. The rate of malignancy in incidental thyroid nodule can again quite variable based on how it was discovered and range from 4% to 50%. (The overall risk is approximately 15%).