How long would it take for small fracture to show up on a bone scan?

If acute fracture,: If u have sustained an acute fracture( which bone ?) it show show up on a 3- phase bone scan almost immediately. If , by small u mean size of the fracture. If u mean small( like it may not have broke) then the bone scan will probably be negative.

24 -48 hrs: Usually most fractures are evident at 24 to 48 hours following acute fracture. Fractures in small bones of hands and feet as well as ribs can be detected. Detection some times depends on mineralization of patient. Neurologically insufficient and osteoporotic patients delay the time scale. Definition of small fracture enters into the equation. Bone scan will not show soft tissue injuries.