The thyroid gland is a butterfly-shaped endocrine gland located in the front of the neck, just below the larynx (voice box). It produces thyroid hormones (T3 and T4) that regulate the body’s metabolism, growth, and development, as well as calcitonin, which helps regulate calcium levels. On ultrasound, the normal thyroid appears as a homogeneous, moderately echogenic (bright) structure, more echogenic than the surrounding strap muscles. Thyroid ultrasound is one of the most commonly performed ultrasound examinations, used to evaluate thyroid nodules, goiter (enlargement), thyroiditis (inflammation), and to guide fine needle aspiration biopsy of suspicious nodules. The TI-RADS classification system provides a standardized framework for assessing thyroid nodule risk based on sonographic features.
Sonography Term