Clinical Application of Thyroid and Parathyroid Ultrasonography in the Outpatient Clinic

Thyroid and parathyroid ultrasonography is a noninvasive, quick, and convenient method for observing morphologic abnormalities of the thyroid and parathyroid glands. The examination is also inexpensive in some countries. Given these qualities, the method can be used in outpatient clinics as a stethoscope for physical examination. When a pure cyst is observed, aspiration can be performed to treat the lesion, without the additional cost of cytology. Ultrasonography enables subacute thyroiditis to be easily differentiated from other lesions. If a hypoechoic lesion is observed associated with microcalcification, papillary or medullary thyroid cancers can be suspected early on the basis of ultrasonography. Combining information regarding the extent of the cancer lesions using ultrasonography and differentiation of cancer lesions by cytomorphology enables the most suitable method of surgery and management to be chosen for patients. This examination method is also important in the follow-up of papillary thyroid cancer recurrence in the neck lymph nodes, with or without elevation of serum thyroglobulin levels. Color Doppler is helpful in following up activity in Graves disease to determine whether medication can be discontinued. Ultrasonography is also useful in determining when to operate on patients with Graves disease or Hashimoto thyroiditis associated with thyroid nodules, and in avoiding unnecessary surgery in euthyroid patients with ectopic thyroid nodules. In patients with elevated serum calcium and parathyroid hormone levels, parathyroid ultrasonography is useful in determining the location of abnormal parathyroid glands and in reducing the need for a parathyroid sestamibi scan. In conclusion, it is of economic and medical importance to move the ultrasonography machine out of the examination laboratory and into the outpatient clinic.