Brief Answer: INFECTION, INJURY, INFLAMMATION OR MALIGNANCY. Detailed Answer: Hello Thanks for writing to us with your health concern. See, basically during a bone scan, radioactive substance is injected, which is specifically picked up the bones. Wherever there is enhanced blood flow to the bone, more substance is concentrated leading to hot spots or hyperaemia being seen. This hyperaemia can indicate a lot of things - so a bone scan is not specific in that sense. Commonly, areas of fracture / bone injury show up as hyperaemic spots. Inflammation such as arthritis in the pelvic bone, or infection due to abscess within the bone can give a hyperaemic picture. Primary malignancy within the bone, or that which has spread from other organs, can given rise to a hyperaemic appearance. Similarly, healing bone fractures, and healing infections / inflammations also have areas of heightened blood flow around, so they too appear hyperaemic. Basically, it is a wide range of possibilities. Please upload your report ( not the scan pictures, but the typed worded report ) and write a bit more about your symptoms, so that I can be more specific. All the best. Please feel free to discuss further.