Diagnostic role of ultrasound and elastosonography in nodular goiter

Among several ultrasound patterns, thyroid nodule hypoechogenicity, spot microcalcifications, and an absent halo sign are used for predicting increased risk of thyroid malignancy. The predictive value of ultrasound, however, increases at the expense of its sensitivity, and malignancy is predicted with high specificity only when multiple ultrasound features are simultaneously present. Ultrasound features are important in determining the strength of the indication for carrying out fine needle aspiration. To this end, a system for standardization of ultrasound features (Thyroid Imaging Reporting and Data System) aids in establishing risk of malignancy. Ultrasound elastosonography is a technique that assesses hardness as an indicator of malignancy risk. It has been carried out in selected studies of patients with thyroid nodules, and has been shown to have a high predictive value for malignancy, which is also maintained in cytologically indeterminate and non-diagnostic nodules. Although conventional ultrasound maintains its pivotal role in defining which nodules are candidates for ultrasound elastosonography characterization, the latter seems to have considerable potential in the diagnosis, or exclusion, of thyroid cancer. This especially concerns thyroid nodules with indeterminate cytology at fine-needle aspiration.