[Value and limitatious of scintigraphy of the sacro-iliac joints using technetium pyrophosphate]

Scintigraphic exploration of the sacroiliac (S.I.) joints by 99 m-technetium pyrophosphate is simple and free of all danger. The fixation of the isotope in the right sacroiliac (R.S.I.) and the "normal" limits of the fixation ratios R.S.I./L.R. and the lumbar rachis (L.R.), visible on the same film. A series of 28 controls having made it possible to calculate the "normal" limits of the fixation ratios R.S.I./L.R. and L.S.I./L.R., the isotopic fixation was measured in 25 patients with sacroiliac inflammation, 21 of whom were rheumatic, 3 infectious. It was shown that scintigraphy could yield useful information on the evolution of sacroiliac inflammation, making an early diagnosis possible, and also contributing to differentiation between rheumatic and infectious inflammation.