Background  Ultrasound and radionuclide are the most commonly used preoperative imaging methods for localization of primary hyperparathyroidism, but the optimal choice has not been determined.

  Objective  To investigate the diagnostic value of primary hyperparathyroidism (PHPT) by high frequency ultrasound combined with radionuclide.

  Methods  A retrospective analysis was performed in 103 patients with primary hyperparathyroidism confirmed by surgical resection and pathology in Chinese PLA General Hospital from January 2017 to December 2019. High frequency ultrasound and radionuclide examination were performed before operation. Biochemical indexes before and after operation were recorded. Based on the pathological results as the gold standard, the diagnostic performance of the two imaging methods alone and the combination was calculated.

  Results  A total of 115 nodules were resected, including 108 parathyroid nodules. The sensitivity of ultrasonography, radionuclide and their combination for diagnosis of PHPT was 88.0%, 93.5% and 98.1%, the specificity was 42.9%, 57.1% and 85.7%, the accuracy was 85.2%, 91.3% and 97.4%, and the AUC was 0.654, 0.753 and 0.919, respectively. Chi-square test for association and McNemar test between ultrasound alone and gold standard demonstrated statistically significant differences (P＜0.05, respectively). There were statistically significant differences in the Chi-square test for association between nuclide with gold standard, and the combination with gold standard (P＜0.01, respectively), and no statistically significant difference was found in McNemar test (P＞0.05).

  Conclusion  Ultrasound combined with radionuclide can improve the preoperative localization diagnosis accuracy for parathyroid lesions.