Parathyroid adenoma best diagnosed by

Ans d Tc99m-Th201 scan. (Ref. Grainger, Diagnostic Radiology 4th ed., 1380)PARATHYROID SCINTIGRAPHY# Tc-99m -thallium substraction scan has 70-92% sensitivity & 43% specificity# Tc-99m sestamibi has 88-100% sensitivity & 91-98% specificity best scan.# Radionuclide scintigraphy with 201 (Technetium-thallium) or "m Tc- MIBI (Technetium-99m sestamibi), using a subtraction technique whereby the image of thyroid gland as shown by "m Tc or 123 I is removed, is thus a noninvasive & other best technique for tumor & other lesions localization of parathyroid gland.Educational points:# Presently, Tc-99m sestambi is the best available agent for parathyroid scanning.# Parathyroid adenoma is the most common cause of primary hyperparathyroidism.# Subperiosteal resorption of bones including erosion of lamina dura, "Pepper-pot" skull, phalangeal erosions, platyspondyly, osteitis fibrosa cystica, Brown's tumors are few typical X-ray findings of hyperparathyroidism.# "Superscan" appearance on Tc99m-MDP bone scan is a prominent feature of hyperparathyroidism.# A notable point - in primary hyperparathyroidism osteoporosis is common feature while in secondray hyperparathy- roidism osteosclerosis ("Rugger-Jersey spine") is a important feature.