Neck ultrasound can be used to try to identify abnormal parathyroid gland. This is best left to be done by the surgeon before operation. Negative ultrasound does not exclude possibility of small tumor.
Sestamibi scan is nuclear medicine procedure for localization of abnormal parathyroid tissue. This involves administration of radioactive contrast and several imaging sessions after that. This method cannot uncover all cases and should be used judiciously.
Fine needle aspiration
Fine needle aspiration is a method of obtaining a tissue sample from suspected parathyroid tumor. This is rarely necessary.