[The scintigraphic investigation of the sacroiliac joints in ankylosing spondylitis ].

Quantitative sacroiliac scintigraphy was performed in 41 patients with ankylosing spondylitis (Sp.a.) and in 90 control subjects. The sacroiliac/sacrum ratio (Index ISG/sacrum) was calculated. We examined the correlation between activity ratio on the one hand and age, subjective complaints, erythrocyte sedimentation rate, and antiinflammatory therapy on the other. Significantly increased uptakes were found in the patient group as a whole compared with the controls. The activity index was highest in the early periods of the disease, so we conclude that scintigraphy is useful in the early diagnosis of Sp.a.