RESUMO
To identify causes of the superscan picture on 99mTc-MDP bone scintigraphy in our clinical environment. Design: A descriptive study. Place and Duration of Study: The study was conducted over a period of two years [January 1997 to December 1998] at the Nuclear Medicine Department [NMD], Institute of Radiotherapy and Nuclear Medicine [IRNUM], Peshawar. Subjects and A total of 27 cases [23 females and 4 males] having super-scan pictures of metabolic bone disease were prospectively evaluated. After three-observer confirmation of bone scan, serum calcium and parathyroid hormone [PTH] estimation was done. The patients having serum PTH greater than 250 pg /ml underwent two-phase parathyroid MIBI scintigraphy [2PP MIBI scan] for the detection of parathyroid adenoma. The patients having positive scans for parathyroid adenoma were subjected to surgery and histopathological confirmation was obtained. Selected cases [N=19] underwent a trial of depot-preparation of vitamin D3 and calcium supplementation. The final diagnosis of 16 patients was osteomalacia [59%], six were histopathologically confirmed cases of parathyroid adenoma [22.2%], One case had toxic adenoma thyroid [3.7%] and one had chronic renal failure [3.7%]. In three cases, final diagnosis could not be made [11.1%]. Osteomalacia and parathyroid adenoma are the two most common causes for the superscan picture on bone scintigraphy