Skeletal SystemJing ChenDpt. of Nuclear Medicine, Tongji Hospital, Tongji Medical College, HUST E Skeletal scintigraphyuSPECT scanuPET scan SPECT bone scanradiopharmaceuticalsorganic compound of bone（骨胶原纤维束、粘多糖蛋白等）osteoid formationmineralization of osteoidMetabolic activityBlood flowSympathetic toneMechanism Radiopharmaceutical加速器生产| Strontium 85 Sr（锶）85A. First radionuclide widely used for bone imagingB. Calcium analog-ion exchangeC. Disadvantage1. High energy gamma emission (514 keV)2. Delayed imaging time（64 d） | Strontium 87m( Sr)87mA. Obtained by yttrium 87( Y)- Sr generator.87 87mB. Lower energy gamma ray-388keV; shorter T1/2-2.8hC. Disadvantages.Slow blood and soft-tissue clearanceLow target-to-background ratios