<prompt> On 3 phase 99m Tc - MDP bone scan, which of the following bone lesions will show least osteoblastic activity -Paget diseaseOsteoid osteomaFibrous dysplasiaFibrous cortical defect  <response>: Osteoid osteoma, Pagets disease and fibrous dysplasia have osteoblastic activity, therefore, show increased radioisotope uptake on bone scan.Fibrous cortical defect shows no radioisotope uptake as it has no osteoblastic activity. 