<prompt> Cold lesion on bone scan suggest:OsteomyelitisLytic lesionOsteoblastic LesionSequestrum  <response>: Ans: B. Osteoclastic activity:cold uptake Ref: Internet Source: Explanation: Interpretation of Bone scans Regional Hyperactivity may be due to: Normal bone growth and remodeling Increased Blood Flow trauma, heterotopic ossification Reactive osteoblastic activity active infections, tumors Reparative bone process healing fractures, tumors, infections Hyper-metabolic activity metabolic disorders They induce an increase in blood flow and osteoblastic activity.which enhance Ca Phosphate local accretion into the hydroxyapatite matrix Cold Spots may be caused by: Malignant Tumors Lung 2-4 Breast 5 Renal 10 Neuroblastomas bone marrow mets Thyroid most cases Multiple Myeloma most cases Bone Abscesses they are surrounded by activity Bone ischemia AVN, sickle cell etc Hemangiomas normal or decreased activity 