Scintigraphic imaging of knee synovitis in osteoarthritis after intra-articular injection of technetium-99m pertechnetate in the unilateral knee

A case of left knee synovitis scintigraphic imaging is presented in a 66-year-old patient with bilateral knee osteoarthritis and a right knee Baker's cyst, who had undergone a 74 MBq (99m)Tc-pertechnetate intra-articular injection in the right knee. The findings in this case were compared with the intravenously injected methylene disphosphonate technetium-99m ((99m)Tc-MDP) scintigraphic findings and could be interpreted as the result of (99m)Tc-pertechenate through blood communication from the right to the left knee. This case implies that (99m)Tc-pertechnetate may be useful in imaging the synovitis in multiple arthroses even up to 60 min after its administration, instead of the 5 min imaging after the injection of (99m)Tc-MDP.