Osteoporosis. Coloured gamma scan (scintigram) of a spine showing vertebral damage (dark) due to osteoporosis. Osteoporosis is a lowering of bone density causing bones to become brittle and liable to fracture. Vertebral fractures due to this disease may cause the bones to crumble and press painfully on the spinal cord. Elderly women are most commonly affected by osteoporosis. At the bottom of the image are pelvic bones. Gamma scanning involves introducing a radioactive isotope tracer into the body. These isotopes (such as Technetium-99m) are chosen for their ability to highlight inshot spotsins such as areas of increased blood supply and inflammation.