[Scintigraphic study of the sacroiliac joints].

Scintigraphic and radiometric investigation with 99mTc-pyrophosphate was carried out on the sacro-iliac joints of 79 patients: 48 with positive form of Behterev disease, 26 -- with probable form of the disease, 2 -- with Reiter syndrome and 2 -- with rheumatoid arthritis. Scintigraphy was combined with radiometric investigation (determination of sacro-iliac -- sacral index) with a view to obtaining quantitative information about the degree of accumulation of pyrophosphate in sacro-iliac joints. The data from the scintigraphic and radiometric investigations were juxaposed to clinical laboratory and X-ray investigations. Forty of the patients examined were HLA-B27 positive and 38 of them-HLA-B27 negative. Sacro-iliac index, determined in 13 healthy subjects (26 sacro-iliac joints) was within the limits of 1.18 +/- 0.094. The average value of the index of the 78 patients examined was 1.41 +/- 0.20. The index, during the first and second X-ray stage was 1.43 +/- 0.13 and 1.45 +/- 0.19 resp. The values decreased to 1.39 +/- 0.18 during the third X-ray stage, whereas in the fourth stage with completely ankylosis of the joints, the index was 1.20 +/- 0.07, being close to that of the control group of healthy subjects.