Clinical diagnostic potentials of thyroid ultrasonography and scintigraphy: an evaluation.

This prospective study was designed to evaluate the potential contributions of high resolution ultrasonography (US) and Tc-99m scintigraphy in the routine diagnosis of thyroid disease. The diagnostic impacts of US and Tc-99m scintigraphy results in 177 patients visiting our thyroid clinic were assessed and scored according to the following criteria: when the information provided by either test supported, confirmed or changed the initial clinical diagnosis, they received scores of 2, 3 and 4 respectively, while score 1 was given when the test itself was useless for the differential diagnosis. US identified focal lesions that both palpation and scintigraphy had failed to detect in 14 (12.1%) of 116 patients with diffuse thyroid diseases, suggesting the necessity of routine US examinations in such patients. US scored higher than scintigraphy in the diagnosis of Hashimoto's thyroiditis, adenoma, adenocarcinoma and adenomatous goiter, and vice versa in the diagnosis of hyperthyroid and euthyroid Graves' diseases. Thus, the advantages of US over scintigraphy for morphological evaluation were confirmed. US was particularly useful for the differential diagnosis of adenomatous goiter from Hashimoto's thyroiditis or a single nodular disease. In contrast, scintigraphy gave functional images, being especially helpful for the differential diagnosis of thyrotoxicosis.