The Added Value of Second-Look Ultrasound in Patients With Primary Hyperparathyroidism With Discordant or Negative Previous Imaging Findings

ObjectiveThe preoperative localization for patients with primary hyperparathyroidism with negative or discordant previous imaging results has always been a difficult problem to be solved in clinical practice. Second-look ultrasound (US) is a viable but underestimated method. This study aimed to assess the added value of second-look US and explore the attributing factors.MethodsAmong 711 surgically confirmed patients with primary hyperparathyroidism, 63 patients with negative or discordant first-time US and ^99mTc-MIBI imaging results were retrospectively studied. All 63 patients underwent second-look US, and the results were compared with intraoperative findings and histopathologic diagnosis. The diagnostic value of second-look US was calculated, and the reasons for changed second-look US results were analyzed.ResultsSixty-three parathyroid lesions were found in 63 patients. The sensitivity, positive predictive value, and accuracy of second-look US were 92.1%, 95.1%, and 88.1%, respectively. Comparing the results of first-time and second-look US, we found that 54.0% of the patients got benefits from second-look US because 34 patients with negative results in the first-time US revealed localization with second-look US. Second-look US was more likely to produce changes in results for lesions with a lower location (OR, 3.23; 95% CI, 1.11-9.43, P < .05) and larger length-to-thickness ratio (3.0 vs 2.4, P < .05).ConclusionSecond-look US is a promising method to determine preoperative localization in patients with negative or discordant results of previous imaging findings. Lesions with elongated shape and lower location are more expected to be detected in second-look US when missed at the first time.