Ultrasonographic evaluation of thyroid nodules in 900 patients: comparison among ultrasonographic, cytological, and histological findings.

Ultrasonography is the most useful tool for detection and evaluation of thyroid nodules. In this study, we present our classification system for ultrasonographic evaluation, which has been routinely performed since 1995. Of 1244 nodules identified by ultrasonography in 900 patients, 1145 nodules demonstrating adequate specimens on fine-needle aspiration biopsy were enrolled in the study.