[Quantitative scintigraphy of the sacroiliac joints]

Effects of gender and age on quantitative sacroiliac joint imaging are discussed controversially. In most investigations the number of controls has been small and might not exactly reflect the change of sacroiliac/sacral (SI/S) ratios related to different age and gender. The aim of our study was to evaluate the changes SI/S ratios according to age and gender. In 125 patients without any history of either diseases or complaints of the sacroiliac joints a bone scintigraphy was obtained and the SI/S ratios were calculated. We observed a significant negative correlation of SI/S index with age. After separation into 4 different age groups a significant decline of the ratios could be shown. There were no significant differences between male and female patients. We conclude that the influence of age on SI/S ratios is substantial. But also many other factors like patient position, algorithm of SI/S ratio calculation, the time interval between application of the radiopharmaceutical and data acquisition may exert effects on SI/S ratios. It seems necessary for each department to evaluate their own age related reference values of SI/S ratios.