Accuracy of 18F-Fluorocholine PET/MR and NeuroEXPLORER PET/CT Imaging for Localization of Parathyroid Tumors

Background: People have 4 parathyroid glands near the thyroid gland in the neck. Surgery is needed to remove a parathyroid gland that is too large or has a tumor. These glands can be in different places, so doctors use an imaging scan with contrast dye to help find them before surgery. Researchers want to know if a different type of scan and a new tracer can make it easier to find the tumors in the parathyroid glands. Objective: To see if PET/MRI and NeuroEXPLORER PET-CT scans with a 18F-FCH tracer are better than existing methods for finding the parathyroid glands. Eligibility: People aged 18 years or older who are scheduled for surgery to remove a parathyroid gland. Design: Participants will have up to 4 clinic or hospital visits. They will be screened. They will have a physical exam and give blood samples. Participants will have a 4-dimensional computed tomography (4D-CT) scan. This is the current way doctors look for parathyroid glands. They will be injected with an iodine-based dye for the 4D-CT scan. They will lie on a padded table that slides into a donut-shaped machine. Participants will have a positron emission tomography (PET)-magnetic resonance imaging (MRI) and NeuroEXPLORER PET-CT scan. For these scans, they will be injected with a radioactive tracer (18F-FCH). They will wait about 30 to 60 minutes for their body to absorb the tracer. They will lie on a padded table that slides into a tube. Their vital signs will be monitored during the scan. Participants will have surgery to remove the target gland. They may need to stay in the hospital for up to 3 nights. Participants will have a follow-up visit 6 months after the surgery. This may be done remotely....