Clinical applications of thyroid ultrasonography

Ultrasound, as applied to the thyroid nodule, was first used in clinical practice for the assessment of thyroid disorders. Differentiating cysts from solid thyroid nodules was determined to be the best indication for ultrasonographic examination of thyroid nodules that had been identified by thyroid scanning. Screening by ultrasound may be of value for small thyroid cancers identified in radiation-exposed individuals. Currently, the clinical applications of thyroid ultrasonography include: 1) assessing thyroid nodule size after radioiodine therapy in patients with toxic adenoma, 2) identifying local recurrences of thyroid cancer, 3) adjunctive studies of thyroid nodules in specific diseases such as acromegaly, and 4) determining the effect of pregnancy on thyroid nodule formation. Ultrasound and fine needle aspiration have been used in the treatment of recurrent thyroid cysts and, more recently, ultrasound-guided laser thermal ablation of thyroid nodules. The pre- and intraoperative management of patients with thyroid cancer is improved with ultrasound examination, according to one report. Thyroid ultrasonography uses no radiation, is easily performed, and is low in cost. The procedure requires experienced operators and interobserver crosschecking to accurately interpret findings.