Objective:To investigate the application value of dual-phase 18F-fluorocholine (FCH) PET/CT imaging in uremic hyperparathyroidism (uHPT). Methods:Twenty patients (10 males, 10 females, age: (46.8±12.3) years) who were diagnosed with uHPT and underwent neck ultrasound and dual-phase (5, 45 min) 18F-FCH PET/CT imaging at Affiliated Hospital of Southwest Medical University between December 2019 and March 2022 were retrospectively analyzed. Patients underwent parathyroidectomy within 1 month after PET/CT imaging. The sensitivity of neck ultrasound and dual-phase 18F-FCH PET/CT imaging for the diagnosis of hyperfunctioning parathyroid glands were compared based on the surgical results. The early- and late-phase 18F-FCH PET/CT images were compared visually and quantitatively, and the difference of SUV max between parathyroid hyperplasia and parathyroid adenoma was compared. The correlations between SUV max and important laboratory parameters and the volume of lesions measured on CT were tested. Fisher exact test, paired t test, independent-sample t test and Spearman rank correlation analysis were used for statistical analysis. Results:A total of 69 masses were removed in 20 patients with uHPT, and 55 parathyroid hyperplasia and 10 parathyroid adenomas were identified by pathology. Dual-phase 18F-FCH PET/CT imaging (87.69%, 57/65) was more sensitive than neck ultrasound (56.92%, 37/65) for the diagnosis of hyperfunction of the parathyroid gland ( P=0.001). The early imaging detected more lesions than late imaging (57 vs 49) respectively, which showing higher sensitivity (87.69%(57/65) vs 75.38%(49/65); P<0.001). The SUV max(5.75±2.21 vs 4.08±1.51) and the corresponding parathyroid-to-thyroid ratio (2.99±0.99 vs 3.57±1.30) were both significantly different between early and late imaging ( t values: 8.28, 4.33, both P<0.001). There were no significant differences between parathyroid hyperplasia and parathyroid adenoma in SUV max(early imaging: 5.08±2.27 vs 6.58±2.24; t=-1.90, P=0.063; late imaging: 3.89±1.54 vs 4.93±1.04; t=-1.94, P=0.059). The sum of SUV max of all lesions in early imaging was not correlated with preoperative serum parathyroid hormone (PTH) or Ca or P or lesion size ( rs values: from -0.22 to 0.06, all P>0.05). Conclusions:Dual-phase 18F-FCH PET/CT imaging has high sensitivity in the diagnosis of uHPT, and early and late imaging shows advantages in different aspects, with good preoperative localization ability. Therefore, for patients with uHPT, it is recommended to complete the dual-phase 18F-FCH PET/CT examination before surgery.