Ultrasound evaluation of the thyroid.

Ultrasound provides a safe noninvasive means of imaging the thyroid gland. It affords a reliable method of distinguishing cystic masses from other types of hypofunctioning thyroid nodules that might require surgical exploration. Due to the reported small frequency of false positive ultrasonic diagnoses (i.e., solid or complex masses being misdiagnosed as cysts), all cystic masses should be confirmed by aspiration. With gray-scale two-dimensional imaging, high-frequency transducers, and careful attention to technique, a reduction in the number of incorrect diagnoses can be expected.