How good is Ultrasound for detecting thyroid abnormalities?
US is very sensitive for identifying nonpalpable thyroid abnormalities. When a focal abnormality is noted in the thyroid parenchyma, it is called a nodule. Screening studies have shown that thyroid nodules are extremely common, especially those less than 1 cm, are more prevalent in women than men, and occur with increasing frequency with advancing age. Up to 67% of senior adults will have focal thyroid lesions when evaluated by US. The vast majority of focal nodules in the thyroid gland prove to be hyperplastic regions containing nonneoplastic cells in which the orderly follicular architecture is disrupted by regions of larger and irregularly shaped follicles, often with abundant colloid and cystic appearance on US.