[Imaging techniques in rheumatology: scintigraphy in rheumatoid arthritis].

Bone scintigraphy is an important tool for staging and follow-up in patients with rheumatoid arthritis, and is part of the training for board certified physicians in nuclear medicine in Germany. Bone scintigraphy uses the accumulation of i.v. injected technetium-99m labeled phosphonates imaged with a gamma camera. Different phases can be defined: perfusion phase (0-60 s p. i.), blood pool phase (2-5 min p. i.), and bone (turnover) phase (2-5 h p. i.). The blood pool phase allowes judgement of inflammatory (soft tissue) components of joint disease ("arthritis"), the bone (turnover) phase of longer lasting bone processes ("arthrosis"). The technical details including documentation of the scintigraphic results are presented according to the procedure guidelines of the German Society of Nuclear Medicine (www.nuklearmedizin. de).