Investigation of choice in parathyroid pathology is -

Ans. is 'd' i.e., Technetium-99 sestamibi scan Localization studieso The diagnosis of primary hyperparathyroidism is established by appropriate biochemical testing.# Localization studies with ultrasonography, technetium-99m sestamibi, CT, or MRI scanning should not be used to establish the diagnosis of primary hyperparathyroidism.# Their utility is questionable when bilateral neck exploration is planned.# However, they are commonly used now. along with intraoperative PTH monitoring, to facilitate unilateral exploration and minimally invasive surgery in those with probable single gland disease.