Computed tomography of the thyroid vascular, encapsulated structure made up of right and left lobes, which are connected at the midline by the isthmus. Each lobe is about 2 cm thick, 3 cm wide, and 5 cm long. The thyroid apex is located superiorly at the level of the mid-thyroid cartilage. The inferior margin of the gland is at the level of the fifth or sixth tracheal ring. The thyroid gland is encapsulated by the middle layer of deep cervical fascia and is part of the visceral space in the infrahyoid neck. It wraps around the trachea and is separated from the oesophagus by the
Thyroid genes being highly thyroid specific. The corresponding specific proteins are mainly involved in thyroid hormone synthesis, such as thyroglobulin, TPO and IYD, and expressed in follicular cells. Other proteins elevated in the thyroid are calcitonin related proteins such as CALCA and CALCB, expressed in the parafollicular c-cells. Excessive production of the thyroid hormones is called hyperthyroidism, which is most commonly a result of Graves' disease, a toxic multinodular goitre, a solitary thyroid adenoma, or inflammation. Other causes include drug-induced excess of iodine, particularly from amiodarone, an antiarrhythmic medication; an excess caused by the preferential uptake of iodine by the thyroid