Sonography of the thyroid gland

Sonography of the thyroid gland is one of the basic tools in the diagnosis of thyroid diseases and allows the quantification of thyroid volume, morphology and localisation of thyroid nodules. Sonography can help to determine size and morphology of thyroid nodules. Although the majority of malignant thyroid nodules are of low echogenicity, this parameter, however, is of low specificity. Color-coded duplex sonography allows quantification of thyroid tissue and assessment of nodules vascularity in recent years. Use of color-coded duplex sonography might be helpful in special cases (hyperthyroidism in Graves' disease, sublocalisation of thyroid nodules with normal echogenicity), but appears to play a minor role in routine diagnostics. Since sonography and color-encoded sonography did not differentiate malignant and benign lesions, scintigraphy and fine-needle aspiration of cold thyroid nodules further play a major role in diagnosis of thyroid nodules.