Accuracy of Neck Ultrasonography in Predicting the Size and Location of Parathyroid Adenomas

Objectives: Ultrasonography (US) is a reliable tool for the preoperative localization of parathyroid adenomas (PTAs). The aim of this study was to evaluate the accuracy of US for estimating both the size and the location of PTAs and the effect of operator expertise. Study Design: Retrospective cohort study. Setting: A single tertiary medical center. Subjects and Methods: All patients who underwent parathyroidectomy for primary hyperparathyroidism between 1996 and 2012 were included. The estimated PTA localization and size by preoperative ultrasound were compared with the intraoperative findings and pathology report. Results: The cohort included 410 patients. US correctly localized the adenoma in 76% of cases with a sensitivity of 76.2% and a positive predictive value of 86.8%. Measurements were least accurate for adenomas measuring <1 cm in diameter (24%). Scans made by a single senior operator specializing in the neck had a higher accuracy rate than scans made by multiple operators, with a significant difference for small adenomas (P <.001). Conclusions: US is an accurate and sensitive tool for evaluating PTA size and location. Neck US is less accurate for small adenomas (<1 cm). In these cases particularly, the experience and expertise of the US operator may play an important role.