Describe the phases of a three-phase bone scan. List eight causes of focal extraosseous uptake List seven causes of increased renal uptake List six causes of decreased renal uptake List six causes of diffuse (widespread) extraosseous uptake What are the indications for a three-phase bone scan? Book traversal links for Extraosseous activity ‹ Bone Scans Up Describe the phases of a three-phase bone scan. ›