Hybrid imaging of benign skeletal diseases

^99mTc-methylene diphosphonate (^99mTc-MDP) is the most commonly used bone radiopharmaceutical for scintigraphic assessment of skeletal abnormalities. The compound, an analogue of pyrophosphate, is chemisorbed onto bone surface. Its uptake depends on local blood flow and bone turnover. As little as 5-10% change in lesion to normal bone uptake ratio is required to detect pathology on bone scintigraphy (BS) preceding their detection on plain radiographs or CT by 2-18 months.1 Based on these characteristics, BS with ^99mTc-MDP is highly sensitive for the detection of various benign skeletal abnormalities associated with increased bone turnover including trauma, osteomyelitis, osteoporosis, metabolic skeletal disease, degenerative changes, etc.