Autoradiographic findings in experimental sinusitis in rabbits.

In order to study the effect of a purulent infection in the sinus cavity on the uptake of radionuclide in the surrounding bone, two series of experiments were performed; one using 45Ca-chloride (T1/2 = 153 d), that was given intravenously in a dose of 50 MBq to the previously infected animal, and in the other 99Tcm-DP was used in a dose of 530-1600 MBq. The animals were killed 4-6 hours later and analyzed using an autoradiographic technique and histological examination. Chronic unilateral infection of the maxillary sinus was induced experimentally according to the technique described by Kumlien and Schiratzki (1985). An acute unilateral maxillary sinusitis was induced experimentally according to Johansson et al. (1988). An increased uptake of 99Tcm-DP in the bone surrounding the sinus cavity with an infected mucosa could be seen. This uptake could be seen four days after induction of an acute, purulent, pneumococcal sinusitis, and five months after the induction of an purulent, chronic sinusitis. No increase in uptake could be seen in the mucosa of the sinus with purulent infection. The beta-emitting nuclide gave better resolution in autoradiography than did the gamma-emitting nuclide, and would give better possibilities in identifying structures; however, the specificity to bone of 45Ca was not high enough to be suitable.