Abstract
In hypothyroidism, which is as old as humanity, ultrasound has been the first and most important imaging examination in recent decades. This disease is involved in almost all steps in the spectrum from inflammatory diseases to cancer of the thyroid gland. Thyroid ultrasound is a critical tool in the differential diagnosis of hypothyroidism. if thyroid antibodies are negative. It is helpful to determine whether the thyroid is present and to visualize the parenchyma. In a hypothyroid patient, the US may lead to cost savings. if a typical autoimmune pattern is present on US, as a cost-reducing move, further investigations may not be required for the diagnosis of Hashimoto’s thyroiditis. Moreover, the ultrasound image may contribute to the decision process whether to treat patients with positive antithyroid antibodies who are euthyroid or have only a mild subclinical hypothyroidism.