BACKGROUND: METHODS: RESULTS: Of the 60 patients, 4D-CT accurately lateralized 73% and localized 60% of abnormal glands found at operation. Single candidate lesions (46/60) were confirmed at operation in 70%. When multiple lesions were identified on 4D-CT (14/60), accuracy dropped to 29% (P = .03). The accuracy of 4D-CT was not different between primary and reoperative cases (P = .79). Of the 8 patients with multigland disease diagnosed perioperatively, 5 had multiple candidate lesions noted on 4D-CT. In 94% (48/51) of patients, a >50% drop in intraoperative parathormone (IOPTH) level was achieved after resection and 87% (48/55) had long-term cure with a median follow-up of 221 days. CONCLUSION